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Megalin, a type I transmembrane protein, serves as a multi-ligand endocytic receptor in the apical membrane of proximal tubules. Its ectodomain and full-length forms are excreted into human urine, with the former being more abundant. We previously developed two types of sandwich enzyme-linked immunosorbent assays (ELISAs) utilizing monoclonal antibodies that target the amino-terminal ligand-binding domain-I and the carboxyl-terminal cytoplasmic region of human megalin, respectively. The former, termed "A-megalin" ELISA, primarily identifies ectodomains of megalin, whereas the latter, "C-megalin" ELISA, specifically recognizes full-length megalin originating from urinary extracellular vesicles. This study developed novel sandwich ELISAs to assess mouse urinary A-megalin and C-megalin, thereby facilitating studies involving these biomarkers in mouse disease models. Immunoblotting and immunohistochemistry of monoclonal antibodies against human megalin were performed to assess their compatibility with mouse megalin in novel sandwich ELISAs, which were constructed and validated using human assay protocols. Immunoblot analysis of megalin in urinary extracellular vesicles and supernatant was performed to investigate the ratio of ectodomain to full-length forms in mouse urine. Stable measurements having a precision and accuracy within 15 % were achieved in the measurement of quality control samples. A-megalin and C-megalin were detectable in the urine of C57BL/6 mice, whereas most urine samples from kidney-specific conditional megalin-knockout mice were below detection limits. Ectodomain forms of megalin were at least approximately 70 times more abundant than the full-length form, even in mouse urine. In conclusion, we successfully developed sandwich ELISAs for assessing mouse urinary A-megalin and C-megalin to evaluate primarily ectodomain and full-length forms of megalin, respectively., Competing Interests: Declaration of competing interest A.S. received research grants from Denka Co., Ltd., (Copyright © 2024. Published by Elsevier B.V.)

Early diagnosis of pregnancy is directly related to cost-effective livestock production. We produced a rat monoclonal antibody (mAb) against synthesized porcine early pregnancy factor (pEPF) using conventional hybridoma technology and used it as a tool for the detection of early pregnancy in Duroc sows. The rat pEPF-mAb showed reactivity to uterine tissues of pregnant sows 20 or 30 days post-mating (day 0 defined as the day of mating) and non-pregnant sows (confirmed signs of estrus) in western blotting. Immunohistochemical analysis confirmed that pEPF was located in the stromal and grand epithelial tissues of pregnant sows 20 or 30 days post-mating. In the enzyme-linked immunosorbent assay, pEPF expression in urine and blood showed similar results, with the highest expression observed in pregnant sows 20 days post-mating, whereas there was no significant difference in expression levels between non-pregnant sows and pregnant sows 30 days post-mating. The pEPF-mAb-based pregnancy diagnostic kit can be applied to pig urine samples non-invasively collected at 20 days post-mating with 70 % accuracy. Further improvements to the kit's diagnostic performance may lead to substantial benefits for the swine industry, facilitating more efficient and accurate reproductive management., Competing Interests: Declaration of competing interest No potential conflict of interest was reported by the author(s)., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: An in-house Histoplasma urine antigen test for cats might be desirable in certain situations., Objective: To validate and compare the diagnostic performance of a monoclonal antibody-based IMMY urine Histoplasma antigen enzyme immunoassay (IMMY EIA) to the commercially available urine Histoplasma antigen enzyme immunoassay (MiraVista Diagnostics, MV EIA)., Animals: One hundred ninety-three urine samples from 105 client-owned and purpose-bred research cats., Methods: Cats were classified as Histoplasma positive or negative based on diagnostic investigation. The IMMY EIA and MV EIA were performed on all urine samples. Correlation and agreement between the assays were determined. Diagnostic performance was determined and compared between assays., Results: The IMMY EIA, with a 0.25 ng/mL diagnostic cutoff, provided a diagnostic sensitivity (DSe), diagnostic specificity (DSp), and diagnostic accuracy (DAc) of 89% (95% confidence interval [CI]; 73%-97%), 80% (67%-89%), and 83% (74%-90%), respectively. The IMMY EIA, with a 1.1 ng/mL diagnostic cutoff, provided a DSe, DSp, and DAc of 77% (95% CI 60%-90%), 97% (88%-100%), and 89% (81%-95%), respectively. The MV EIA provided a DSe, DSp, and DAc of 94% (95% CI 81%-99%), 97% (89%-100%), and 96% (90%-99%), respectively. Moderate overall agreement was found between MV EIA and IMMY EIA using the 0.25 ng/mL cut-off (к = 0.44; 95% CI 0.31-0.57) and the 1.1 ng/mL cut-off (к = 0.43, 95% CI, 0.31-0.56)., Conclusions and Clinical Importance: The IMMY EIA might be useful as a diagnostic test for histoplasmosis in cats. Further modifications of the IMMY EIA are required to achieve the diagnostic performance of the MV EIA., (© 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Leptospirosis is underdiagnosed due to low sensitivity, need of specialised equipment, and expensive reagents for serological and molecular diagnosis respectively. Considering the sensitivity, rapidity, inexpensive reagents and collection of clinical samples, the monoclonal antibody based antigen detection method from urine samples has been developed and evaluated. LigA (LK90) based B-cell specific epitopes were predicted and synthesised as peptides for the production of monoclonal antibody. LK90 543 : SNAQKNQGNA (amino acids: 543 to 552), and LK90 1110 : DHHTQSSYTP (amino acids: 1110 to 1119) with VaxiJen score of 1.3719 and 1.2215, respectively were used. Thirty two and 28 urine samples from confirmed and seronegative healthy human subjects, respectively were included for the evaluation of MAb-based dot blot ELISA. The specificity of the evaluated MAbs, P1B1 and P4W2 were found to be in the range of ~93-96%. Moreover, the MAbs did not show cross-reactivity with other bacterial antigens as confirmed by IgG ELISA, further validating its specificity for leptospiral antigens. These findings suggest that the developed MAb based dot blot ELISA is a simple, rapid performed in less than 8 h, inexpensive with a ICER of $8.7/QALY, and affordable in developing countries and area where laboratory facilities are limited.

Objective: To generate monoclonal antibodies (MAbs) for developing a rapid malaria diagnostic urine-based assay (RUBDA), using Plasmodium-infected human urinary antigens., Methods: Plasmodium-infected human urinary (PAgHU) and cultured parasite (CPfAg) antigens were used to generate mouse MAbs. The reactivity and accuracy of the MAbs produced were then evaluated using microplate ELISA, SDS-PAGE, Western blotting assay, microscopy and immunochromatographic tests., Results: Ninety-six MAb clones were generated, of which 68.8% reacted to both PAgHU and CPfAg, 31.3% reacted to PAgHU only, and none reacted to CPfAg only. One promising MAb (UCP4W7) reacted in WBA, to both PAgHU and CPfAg, but not to Plasmodium-negative human urine and blood, Schistosoma haematobium and S. mansoni antigens nor measles and poliomyelitis vaccines., Conclusion: MAb UCP4W7 seems promising for diagnosing Plasmodium infection. Urine is a reliable biomarker source for developing non-invasive malaria diagnostic tests. SDS-PAGE and MAb-based WBA appear explorable in assays for detecting different levels of Plasmodium parasitaemia., (© 2016 John Wiley & Sons Ltd.)

The introduction of the serum-free light-chain (S-FLC) assay has been a breakthrough in the diagnosis and management of plasma cell dyscrasias, particularly monoclonal light-chain diseases. The first method, proposed in 2001, quantifies serum-free light-chains using polyclonal antibodies. More recently, assays based on monoclonal antibodies have entered into clinical practice. S-FLC measurement plays a central role in the screening for multiple myeloma and related conditions, in association with electrophoretic techniques. Analysis of S-FLC is essential in assessing the risk of progression of precursor diseases to overt plasma cell dyscrasias. It is also useful for risk stratification in solitary plasmacytoma and AL amyloidosis. The S-FLC measurement is part of the new diagnostic criteria for multiple myeloma, and provides a marker to follow changes in clonal substructure over time. Finally, the evaluation of S-FLC is fundamental for assessing the response to treatment in monoclonal light chain diseases.

Rationale: Use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to monitor serum and urine samples for endogenous monoclonal immunoglobulins. MALDI-TOFMS is faster, fully automatable, and provides superior specificity compared to protein gel electrophoresis (PEL)., Methods: Samples were enriched for immunoglobulins in 5 min using Melon Gel™ followed by reduction with dithiothreitol for 15 min to separate immunoglobulin light chains and heavy chains. Samples were then desalted using C4 ZipTips, mixed with sinapinic acid matrix, and analyzed on a Bruker Biflex III MALDI-TOF mass spectrometer., Results: Monoclonal immunoglobulin light chains were identified in serum and urine samples from patients with a known monoclonal gammopathy using MALDI-TOFMS with minimal sample preparation., Conclusions: MALDI-TOFMS can identify a monoclonal immunoglobulin in serum and urine samples. The molecular mass of the monoclonal immunoglobulin light chain is obtained providing unprecedented specificity compared to PEL. In addition, the methodology can be automated, making it a practical alternative to PEL., (Copyright © 2015 John Wiley & Sons, Ltd.)

Background: Different patterns between serum immunofixation electrophoresis (SIFE) and urine immunofixation electrophoresis (UIFE) happen occasionally and laboratorians should understand the mechanisms behind the differences and additional tests required for complicated cases., Methods: We investigated a complicated multiple myeloma case that showed inconsistent patterns of SIFE and UIFE. To differentiate monoclonal proteins (M-proteins), the urine sample was treated with dithiothreitol to open up the IgA molecule and urine free light chain assay was used for free light chain analysis., Results: The patient's SIFE indicated 2 IgA λ and 1 IgM κ M-proteins, while UIFE revealed monoclonal free λ light chains and a suspicious monoclonal IgA κ protein. Subsequent treatment of the urine sample with dithiothreitol and urine free light chain assay demonstrated that the suspicious monoclonal IgA κ protein was actually a monoclonal IgA λ and a free κ light chain that had similar electrophoretic mobility., Conclusions: The differences identified between SIFE and UIFE in this case are due to the limitation of immunofixation electrophoresis on different specimen types and intra-molecular disulfide bonds formation in IgA. The laboratorians must be cognizant of the strengths and limitations of the procedure being performed and the ancillary testing techniques available to solve the problem., (Copyright © 2014 Elsevier B.V. All rights reserved.)

This study examined the effects of denosumab, an anti-RANKL antibody that inhibits bone resorption, on bone histomorphometry in adult ovariectomized cynomolgus monkeys (OVX cynos). A month after surgery, OVX cynos were treated with subcutaneous vehicle (OVX-Veh) or denosumab (25 or 50mg/kg/month) for 16months (n=14-20/group). Sham controls were treated with vehicle (Sham-Veh; n=17). Areal and volumetric BMD, urine NTx, and serum osteocalcin were measured at baseline and months 3, 6, 12, and 16. Double fluorochrome labels were injected prior to iliac and rib biopsies at month 6 and month 12, and prior to sacrifice at month 16. Histomorphometry was performed on these biopsies, the tibial diaphysis, the L2 vertebra, and the proximal femur. Strength of humeral cortical beams, femur diaphysis, femur neck, and trabecular cores of L5-L6 vertebrae was determined by destructive biomechanical testing. There was no evidence of woven bone, osteomalacia, or other bone histopathologic changes with OVX or with denosumab. OVX-Veh animals exhibited significantly greater bone remodeling at all skeletal sites relative to Sham-Veh controls. Both doses of denosumab markedly inhibited bone remodeling at all sites, including significant reductions in trabecular eroded surfaces (48-86% lower than OVX-Veh controls), cortical porosity (28-72% lower), and dynamic parameters of bone formation (81-100% lower). Decreased fluorochrome labeling with denosumab was related to reductions in cortical porosity and trabecular eroded surfaces, and regression analyses suggested that these reductions contributed to denosumab-related increments in BMD and bone strength. Denosumab-treated animals with the lowest levels of fluorescent labeling exhibited the greatest structural bone strength values at each site. Intracortical remodeling had no relationship with material properties including ultimate strength, elastic modulus or toughness (r(2)=0.00-0.01). These data suggest that remodeling inhibition with denosumab improved structural strength without altering material properties under these experimental conditions. Greater structural strength in the denosumab-treated animals can be primarily explained by the combined effects of increased trabecular and cortical bone mass, and reductions in trabecular eroded surfaces and cortical porosity., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Purpose: Anti-Aβ Ab2 (Ab2) is a humanized monoclonal antibody against amino acids 3-6 of primate (but not rodent) amyloid β (Aβ) and is being evaluated for the treatment of Alzheimer's disease (AD). This study was conducted to predict the human pharmacokinetics of Ab2., Methods: In vivo PK profile of Ab2 in preclinical species and in vitro mechanistic studies in preclinical and human systems were used for pharmacokinetic predictions., Results: In Tg2576 and PSAPP mice that have ~100-fold higher circulating levels of human Aβ compared to humans, elimination of Ab2 was target-mediated, such that exposure was 5-10 fold lower compared to wild-type rodents or to PDAPP mice that have human Aβ concentrations in plasma similar to humans. In cynomolgus monkeys, the t(1/2) of Ab2 was faster (<2.5 days) compared to that of the control antibody (~13 days). The fast elimination of Ab2 in cynomolgus monkeys was linked to off-target binding to cynomolgus monkey fibrinogen that was also causing incomplete recovery of Ab2 in cynomolgus monkey serum in blood partitioning experiments. Ab2 had significantly weaker to undetectable binding to human (and mouse) fibrinogen and had good recovery in human serum in blood partitioning experiments., Conclusions: These data predict that elimination of Ab2 in healthy or AD humans is expected to be slow, with t(1/2) similar to that observed for other humanized antibodies.

Background and Objectives: Membranoproliferative glomerulonephritis (MPGN) is an immune complex-mediated glomerulonephritis characterized by subendothelial and mesangial deposition of immune complexes. Autoimmune diseases and chronic infections, such as hepatitis C, are commonly recognized causes of MPGN; however, monoclonal gammopathy is a less widely recognized cause of MPGN., Design, Setting, Participants, & Measurements: We reviewed all renal biopsies of MPGN in Mayo Clinic patients during a 6-year period to determine the association of monoclonal gammopathy with MPGN. Results were correlated with electrophoresis studies and bone marrow biopsies to clarify the relationship between MPGN and gammopathies., Results: Of 126 patients with MPGN, 20 did not have workup for hepatitis B or C. Of the remaining 106 patients, 25 (23.5%) were positive for hepatitis B or C. Of the 81 hepatitis-negative patients, 13 were not evaluated for gammopathies. Of the remaining 68 patients, 28 (41.1%) had serum and/or urine electrophoresis studies positive for monoclonal gammopathy. Serum immunofixation electrophoresis was the most sensitive method for diagnosing monoclonal gammopathy. Renal biopsy showed a membranoproliferative pattern of injury; immunofluorescence microscopy was often instrumental in diagnosing the underlying gammopathy. On the basis of the bone marrow biopsy, monoclonal gammopathy of undetermined significance was the most common entity associated with MPGN. Other, less common causes included multiple myeloma, low-grade B cell lymphoma, and chronic lymphocytic leukemia., Conclusions: Monoclonal gammopathy is an important and common cause of MPGN; therefore, all patients with a diagnosis of MPGN should be evaluated for an underlying monoclonal gammopathy.

Background: A nephelometric assay for identifying free light chains (FLC) of immunoglobulin in serum is commercially available. Although this assay is not specific for monoclonal FLC, an abnormal kappa/lambda ratio is thought to presumptively identify monoclonal FLCs. It has been proposed that serum FLC assays can replace urine immunofixation electrophoresis (IFE) for routine detection. This proposal seems to be based upon testing of samples retrospectively drawn from patients mostly with myeloma or known primary amyloidosis-conditions that are less frequently observed in general laboratory practice., Methods: Prospective analysis of 5 patient samples by standard care techniques with serum/urine IFE compared with serum FLC nephelometric assay. Rather than classical myeloma, cases were selected on the basis of unusual or equivocal atypical serum protein electrophoresis patterns., Results: In all 5 cases, the nephelometric method for free light chains was negative by virtue of serum FLC kappa/lambda ratio being within the reference range, contrasting with monoclonal proteins or free light chains detected by serum/urine IFE., Conclusions: Since peculiar or unusual patterns are more commonly observed in general practice, these cases illustrate the pitfalls of relying solely on the serum free light chain analysis method in order to establish the presence of monoclonal FLC.

In this study, we prepared monoclonal antibodies against morphine, methadone, babital, methamphetamine, and phencyclidine, then developed a dot-ELISA method by such antibodies to test their efficacy in clinical application and the screening of urine samples. It was found that there were 36 narcotics-positive drug users, including 28 morphine positive, six methamphetamine positive, and two positive for both. All the results were confirmed by commercial drug testing kits.

Cast nephropathy is the most common cause of renal disease in multiple myeloma, however, treatment with plasma exchange remains controversial even after 3 randomized controlled studies. We sought to determine the importance of diagnostic confirmation and goal directed therapy in the treatment of cast nephropathy in forty patients with confirmed multiple myeloma and renal failure who underwent plasma exchange. A positive renal response was defined as a decrease by half in the presenting serum creatinine and dialysis independence. No baseline differences were noted between eventual renal responders and non-responders. Three quarters of the patients with biopsy proven cast nephropathy resolved their renal disease when the free light chains present in the serum were reduced by half or more but there was no significant response when the reduction was less. The median time to a response was about 2 months. In patients without cast nephropathy, renal recovery occurred despite reductions in free light chain levels of the serum. No association was found between free light chains in the serum, urinary monoclonal proteins, overall proteinuria and cast nephropathy. We found that the relationship between renal recovery and free light chain reduction was present only in patients with biopsy proven cast nephropathy showing the importance of extracorporeal light chain removal in this disease.

Ten years after the first clinical application of Rituximab, an anti-CD20 recombinant monoclonal antibody, immunotherapy has become common practice in oncology wards. Thanks to the great diversity of the immune system and the powerful methodology of genetic engineering, the pharmacologic potential of antibody-based therapy is far from exhaustion. The recent application of Trastuzumab, an antibody to a receptor tyrosine kinase, in adjuvant breast cancer therapy marks the beginning of a new phase in cancer treatment. Here we discuss molecular mechanisms of antibody-based therapy, the emerging ability to target minimal disease and the therapeutic potential of combining antibodies with other modalities.

Context: Emergency department physicians frequently request urine drug screens, but many are unaware of their limitations, including the potential for false-positive results. Promethazine, a phenothiazine derivative, is used for the treatment of allergies, agitation, nausea, and vomiting. Many patients taking promethazine are subject to urine drug screens and any potential interferences are important to recognize., Design: During an 11-month period, all patients presenting to the Massachusetts General Hospital emergency department who had a finding of promethazine in their serum drug screen, and who also had a urine drug screen performed, were selected for inclusion in the study. The urine drug screen results (n = 22 patients/samples) were then studied., Objective: To determine if promethazine use can cause false-positive urine amphetamine results in widely used drug of abuse immunoassays., Results: Thirty-six percent of patients taking promethazine had false-positive test results for urine amphetamines using the EMIT II Plus Monoclonal Amphetamine/Methamphetamine Immunoassay. Sixty-four percent of patients showed cross-reactivity greater than 20% higher than the blank calibrator rate. In a separate, related study, no promethazine-induced false-positive results were seen with the EMIT II Plus, Triage, and TesTcard 9 amphetamine assays, or the Triage methamphetamine assay. Reduced chlorpromazine interference was also seen with these other assays., Conclusions: False-positive urine amphetamine results can be obtained in patients taking promethazine. Promethazine metabolite(s), and not the parent compound, are the likely cause of these urine false-positive results obtained with EMIT II Plus Monoclonal Amphetamine/Methamphetamine Immunoassay. Immunoassays from different manufacturers can have very different "interference" profiles, which the pathologist and laboratory scientist must understand and relay to clinicians.

Among genitourinary malignancies, bladder cancer is a common, potentially dangerous and exceedingly costly disease entity. Predicated on substantial gains in our understanding of the natural history and molecular biology of bladder cancer, recent years have seen an explosion of new applied technologies to aid clinicians in the management of bladder cancer. Herein we present a systematic overview of general conceptual issues and specific strategies of potential relevance to the clinical evaluation of patients with bladder cancer. A number of basic epidemiological issues provide the relevant background within which we should consider candidate biomarkers. Within this framework, we highlight a number of important recent research findings representative of the large number of candidate bladder cancer biomarkers that have emerged. With several markers already having obtained regulatory approval for clinical use, this topic is of clear relevance not only to researchers but also to the practicing physician. Bladder cancer is a common, costly, and potentially dangerous disease with the opportunity for significant technological inroads in the area of applied biomarkers. An appreciation of basic epidemiological considerations informs our consideration of the state of the art and identifies specific strategies amenable to further innovation.

The detection of a monoclonal immunoglobulin in serum or urine usually raises concerns about the size of the underlying B-cell-derived clone and possible systemic effects caused by its expansion. However, a small clone can synthesize a very toxic protein, producing devastating systemic damage and protean clinical presentations. The resulting "monoclonal component-related diseases," although difficult to diagnose, may be progressive and even fatal. The monoclonal protein can aggregate and deposit systemically as occurs in light-chain amyloidosis, monoclonal immunoglobulin deposition disease, crystal-storing histiocytosis, and monoclonal cryoglobulinemia. Alternatively, some monoclonal proteins possess antibody activity toward autogenous antigens and cause chronic cold agglutinin disease, mixed cryoglobulinemia, and peripheral neuropathies. Other humoral mediators may contribute to neuropathy in variant disorders such as the POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome. The clone synthesizing the noxious monoclonal proteins is often small, and sensitive techniques may be required to detect these immunoglobulins. A delay in diagnosis can allow irreversible organ damage and dramatically shorten survival. Prompt recognition of suggestive signs and symptoms should trigger a thorough diagnostic approach to reach the correct diagnosis quickly, because this is the key to effective therapy. Although the treatment of these conditions is not optimal, significant advances have been made, improving the duration and quality of life.

The use of MoAb therapy for the treatment of HCL offers great promise and potential for improving progression-free survival. Rituximab has activity in the setting of previously treated HCL and the ability to eradicate MRD after 2-CdA given as frontline therapy. Alemtuzumab, epratuzumab, Hu-Max-CD20, and other candidate MoAb's should be studied in HCL. Appropriate pharmacologic investigation, use of antigen modulation, and assessments of soluble antigen levels should be considered with future clinical trial s of MoAb's in HCL to optimize therapeutic strategies.

Unlabelled: AIM of this study was the assessment of the radiation exposure from preparation and application of (90)Y-Zevalin, the measurement of the dose rate at the patient, the exposure of family members as well as the determination of the activity concentration in urine of patients., Methods: Overall data from 31 therapeutic administrations carried out in four institutions were evaluated. During preparation and application of (90)Y-Zevalin the finger exposures of radiochemists, technicians, and physicians were measured. The dose rate of the patient was measured immediately after radioimmunotherapy. In patients treated in a nuclear medicine therapy unit, urine was collected over a two day period and the corresponding activity was determined. Family members of outpatients were asked to wear a dosimeter over a seven day period., Results: During the preparation we found a maximum skin dose of 6 mSv at the average, and during application of 3 mSv, respectively. After administration of (90)Y the dose rate was 0.4 +/- 0.1 microSv/h at 2 m distance. Urine measurements yielded a cumulated 24 h excretion of 3.9 +/- 1.4% and 4.4 +/- 1.4% within 48 h, respectively, that is equivalent to 43 +/- 18 and 50 +/- 20 MBq of (90)Y, respectively. Family members received a radiation exposure of 40 +/- 14 microSv over seven days., Conclusion: During preparation and application of (90)Y-Zevalin appropriate radiation shielding is necessary. For family members as well as nursing staff no additional special radiation protection measures beyond those being common for other nuclear medicine procedures are necessary.

Background: Selective blockade of interactions between leukocytes and vascular endothelium in the gut is a promising strategy for the treatment of inflammatory bowel diseases., Methods: We conducted a multicenter, double-blind, placebo-controlled trial of MLN02, a humanized antibody to the alpha4beta7 integrin, in patients with active ulcerative colitis. We randomly assigned 181 patients to receive 0.5 mg of MLN02 per kilogram of body weight, 2.0 mg per kilogram, or an identical-appearing placebo intravenously on day 1 and day 29. Eligible patients also received concomitant mesalamine or no other treatment for colitis. Ulcerative colitis clinical scores and sigmoidoscopic assessments were evaluated six weeks after randomization., Results: Clinical remission rates at week 6 were 33 percent, 32 percent, and 14 percent for the group receiving 0.5 mg of MLN02 per kilogram, the group receiving 2.0 mg per kilogram, and the placebo group, respectively (P=0.03). The corresponding proportions of patients who improved by at least 3 points on the ulcerative colitis clinical score were 66 percent, 53 percent, and 33 percent (P=0.002). Twenty-eight percent of patients receiving 0.5 mg per kilogram and 12 percent of those receiving 2.0 mg per kilogram had endoscopically evident remission, as compared with 8 percent of those receiving placebo (P=0.007). For the minority of patients in whom an MLN02 antibody titer greater than 1:125 developed, incomplete saturation of the alpha4beta7 receptor on circulating lymphocytes was observed and no benefit of treatment was identifiable., Conclusions: In this short-term study, MLN02 was more effective than placebo for the induction of clinical and endoscopic remission in patients with active ulcerative colitis.

Fanconi's syndrome (FS) is a disorder of sodium-dependent proximal tubule reabsorption, which may complicate plasma cell disorders producing a free monoclonal light chain (LC). FS often occurs in the setting of smoldering myeloma and features cytoplasmic crystalline inclusions of monoclonal kappa LC in proximal tubular cells and malignant plasma cells. Although the clinical and pathological presentation may vary, including lack of crystal formation, monoclonal kappa LCs that underlie FS show a striking genetic and biochemical homogeneity: they almost always belong to the Vkappa1 subgroup of variability and originate from 2 germline genes, O2/O12 or O8/O18. Their variable domain sequences present unusual hydrophobic residues, responsible for the resistance to proteolysis, which leads to LC accumulation in the endocytic compartment of proximal tubule cells. We report a patient with slowly progressive Waldenstrom's macroglobulinemia and full-blown FS with accumulation of a monoclonal kappa LC within proximal tubules, but no detectable crystalline organization. This LC, which belonged to the unusual Vkappa3 subgroup and derived from the L2/L16 germline gene, showed no common substitution with previously described FS kappaI LC and was sensitive to trypsin digestion. These data show that molecular and biochemical characteristics of kappa LCs in patients with FS are more heterogeneous than initially suspected. Mechanisms other than resistance of LCs to endosomal proteolysis probably are involved in the pathogenesis of FS-associated plasma cell dyscrasias.

Radioimmunotherapy (RIT) with radiolabelled monoclonal antibodies (mAbs) is an effective method of achieving myeloablation in leukaemia patients prior to stem cell transplantation (SCT). We wished to compare the approaches of specific binding to leukaemic blasts and non-specific binding to benign red marrow cells, which results in a myeloablative "cross-fire" effect. Therefore, we prospectively evaluated the biodistribution and biokinetics of the anti-CD45 mAb YTH 24.5 and the anti-CD66 mAb BW 250/183 with regard to their suitability for myeloablative RIT. The red marrow selective anti-CD66 mAb BW 250/183 (IgG1) binds to normal granulopoietic cells. In contrast, the anti-CD45 mAb YTH 24.5 (IgG2b) binds to 85-90% of acute leukaemic blasts and almost all haematopoietic white cells. Patients with leukaemic blast infiltration of the marrow <25% and assigned for RIT and SCT were included. Twelve patients (eight male, four female; median age 46+/-7 years) with AML (5), CML (5) or ALL (2) were examined. Both mAbs were labelled with technetium-99m. Within 48 h, 906+/-209 MBq (99m)Tc-anti-CD66 mAb and 760+/-331 MBq (99m)Tc-anti-CD45 mAb were injected consecutively. Scintigraphic and urinary measurements were performed 1, 2, 4 and 24 h after injection. Serum activities were evaluated 2, 5, 10, 15, 30 and 60 min and 2, 4 and 24 h after injection. Compared with the anti-CD45 mAb, the anti-CD66 mAb showed an approximately fourfold higher accumulation in the red marrow, a 2.5-fold lower accumulation in the liver and similar accumulation in the kidneys. The serum activity (% of the injected dose) initially decreased faster for the anti-CD45 mAb but was similar for the two mAbs 24 h after injection: 3.3%+/-1.2% (anti-CD66 mAb) and 2.4%+/-1.1% (anti-CD45 mAb). The cumulated urinary excretion was 17%+/-6.6% (anti-CD66 mAb) and 27.3%+/-7.9% (anti-CD45 mAb) 24 h after application. In these patients with low tumour load, the anti-CD66 mAb BW 250/183 showed more favourable properties in terms of biodistribution and pharmacokinetics. Thus, it appears superior to anti-CD45 mAb YTH 24.5 in selectively increasing the marrow dose and avoiding extramedullary organ toxicity.

Objectives: To test the clinical value and role of uCyt+ as a noninvasive tool for the detection and surveillance of urothelial carcinoma., Methods: Included in this prospective study were 235 patients (mean age 71.5 years, range 32 to 86). Of these, 98 patients had signs and symptoms suggestive of bladder cancer and 137 patients were being followed up after complete transurethral resection of superficial urothelial cancer (UC). All patients underwent urinary cytology and the uCyt+ test performed on ThinPrep (thin layer). All underwent subsequent cystoscopy and evaluation of any suspicious lesion by biopsy., Results: A total of 102 patients had histologically proven UC. In the group of patients with signs and symptoms suspicious of UC, the sensitivity of cytology increased from 5% for G1 to 84.6% for G3 tumors; for uCyt+, it was 85% for G1, 100% for G2, and 92.3% for G3 tumors. Combining cytology and uCyt+, the sensitivity was 85% for G1 and 100% for G2 and G3. In the group of follow-up patients, the sensitivity of cytology increased from 4.3% for G1 to 94.4% for G3 tumors; for uCyt+, it was 78.2% for G1, 70% for G2, and 94.4% for G3 tumors. Combining both tests, the sensitivity was 78.2% for G1, 90% for G2, and 100% for G3., Conclusions: The uCyt+ is a valid test in the detection of UC of all grades and stages. It improves the sensitivity of cytology in low-grade tumors. The two tests combined may be a highly sensitive method to detect UC early in detection and surveillance.

Our previous studies have shown that human mesangial cells (HMCs) incubated with fibrogenic glomerulopathic monoclonal light chains (G-LCs) obtained from the urine of patients with light chain deposition disease produce increased extracellular matrix (ECM) when compared with HMCs not exposed to fibrogenic LCs. This overproduction of ECM proteins is regulated by transforming growth factor-beta (TGF-beta); blocking TGF-beta normalizes the production of ECM proteins. All ECM proteins, after synthesis, have to go through the secretory pathway in the endoplasmic reticulum (ER) and Golgi complex for final maturation and secretion. Blocking the secretory pathway may reduce the accumulation of ECM proteins. We tested the effect of tunicamycin, a specific inhibitor of N-linked glycosylation in the ER which inhibited glycosylation and brefeldin A, an inhibitor of vesicle transport between the endoplasmic reticulum and the Golgi complex, on ECM protein production, both resulting in subsequent upregulation of glucose-regulated protein 78. Overproduction of fibronectin and tenascin by HMCs was normalized by tunicamycin and brefeldin A. Similarly, when HMCs were exposed to exogenous TGF-beta, the increase in fibronectin was reversed by tunicamycin and brefeldin A. Exogenous platelet-derived growth factor-beta (PDGF-beta) did not induce fibronectin overproduction but significantly stimulated proliferation of HMCs. In summary, this study further supports the notion that fibrogenic G-LCs promote the accumulation of ECM proteins, through the actions of TGF-beta. Importantly, the data indicate that altering protein trafficking in the ER results in impairment of secretion of proteins into the ECM. Furthermore, the data also reveal that PDGF-beta and TGF-beta act independently and that PDGF-beta activation by itself cannot increase ECM proteins directly, but only by increasing the number of HMCs., (Copyright 2003 S. Karger AG, Basel)

Background: The aim of this study was to examine the biodistribution of (131)I-herceptin in C3H/Bi mice with transplantable mammary adenocarcinoma with a high frequency of C-erbB2 receptor expression., Material and Methods: Mice C3H/Bi with subcutaneously transplanted mammary adenocarcinoma were used as animal model to study the interaction between C-erbB2 receptor and hercepin, a humanized anti-C-erbB2 monoclonal antibody. The expression of the gene encoding C-erbB2 receptor in the tumours was studied by the RT-PCR technique., Results: Expression of this gene was found in 66% of the studied cases. Similarly, the presence of the C-erbB2 receptor in 77% of the tumours was detected by a Western blot analysis with the use of herceptin. Biodistribution experiments of iodine-labelled herceptin in mice C3H/Bi with adenocarcinoma revealed its maximal accumulation in the tumours at 48 hours since the i.v. injection (7% ID/g). The tumour/muscle radioactivity ratio reached its highest value (above 20) also at 48 hours after the injection., Conclusions: C3H/Bi mice with this adenocarcinoma may be a good experimental model to study herceptin, or its fragments, labelled with different radionuclids for preliminary evaluation of their usefulness in the therapeutic and diagnostic aspects of breast cancer.

The native chimeric human-mouse anti-CD20 antibody IDEC-C2B8 (rituximab) is therapeutically applied in relapsed non-Hodgkin's lymphoma (NHL). The purpose of this study was to evaluate the distribution and pharmacokinetics of iodine-131 labelled rituximab in humans for radioimmunotherapy of relapsed CD20-positive NHL. Thirty-five patients with relapsed NHL were administered 20-40 mg rituximab labelled with 250 MBq (131)I. Biodistribution was determined by the gamma camera whole-body scans, whole-body probe measurements and the analysis of serial blood and urine samples. Dosimetry was performed using the MIRDOSE 3 program. Antibody administration was well tolerated. The whole-body activity showed a mono-exponential decrease with a wide range of effective half-lives, the mean value (88 h) being significantly longer than the half-life of its murine counterpart, tositumomab. This led to appropriately higher dose factors for the whole body and organs. Activity was excreted mainly through the kidneys. Normal organs showed decreasing ratios of organ to whole-body activity over time, whereas the tumour tissue presented different kinetics, with increasing ratios of tumour to whole-body activity as evidence for specific antibody binding. It is concluded that (131)I-labelled rituximab is suitable for pretherapeutic dosimetry. Due to the wide range of whole-body and organ dose factors, individual dosimetry is necessary for radioimmunotherapy with (131)I-labelled rituximab. The therapeutic activities of (131)I-labelled rituximab required to deliver similar doses should be lower than those of its murine counterpart.

Background: This study reports summary biokinetics for 17 patients treated with huBrE-3 antibody labeled with indium-111 ((111)In) and yttrium-90 ((90)Y) in a Phase I dose escalation trial., Methods: Patients were infused with huBrE-3 antibody conjugated to 1-p-isothiocyanatobenzyl 3-methyl- and 1-p-isothiocyanatobenzyl 4-methyl-diethylenetriamine pentaacetic acid (MX-DTPA). The huBrE-3 was labeled with increasing amounts of (90)Y radioactivity according to the following activity regimen: 10 mCi/m(2), 20 mCi/m(2), 33 mCi/m(2), 50 mCi/m(2), and 70 mCi/m(2). In addition to the (90)Y activity, 3--5 mCi of (111)In was labeled to huBrE-3 to serve as an imaging agent. In characterizing the biokinetics of huBrE-3, serial urine and blood samples were acquired. Additionally, whole-body imaging using a scintillation camera was performed at four time points postinfusion., Results: Cumulative urine data yielded a plot of total-body biologic excretion that was relatively flat. Total body regions of interest derived from nuclear medicine scintigrams decreased according to a monoexponential function with a slope slightly greater than the rate of physical decay. When physical decay was combined with the urine biologic excretion rate, the calculated rate of activity decrease was indistinguishable from the scintigraphic rate of decrease in total-body activity., Conclusions: The authors concluded from these observations that the radioactivity remains essentially inside the patient, that biologic excretion of activity from the total body is not appreciable, and that the path for biologic excretion of activity that does occur is via the urine. The half-time associated with the beta (slow) phase for extraction from the blood averages 40.5 hours. Since large amounts of radioactivity do not appear in the urine, and total-body activity is decreased approximately according to physical decay (64.1 hours), activity must pool elsewhere after leaving the blood. The logical place is the skeleton, with possible selective binding to the bone marrow. Bone marrow biopsies from 4 of 7 patients who consented to serial biopsies were supportive of this conclusion., (Copyright 2002 American Cancer Society.)

Objectives: To assess the clinical performance of ImmunoCyt in the detection of upper urinary tract transitional cell carcinoma (UT-TCC). This newly developed immunocytochemical test detects three cellular markers specific for TCC., Methods: Thirty-seven patients with symptoms and/or findings on imaging suggestive of UT tumors were prospectively evaluated. All patients underwent a standard cytologic evaluation and ImmunoCyt testing of voided urine, as well as imaging studies. Urine samples were also obtained from the UT of 32 patients by ureteral catheterization and tested by cytologic analysis and ImmunoCyt., Results: Sixteen patients had UT-TCC as documented by the final histologic evaluation. The sensitivity of testing the voided urine from 37 patients was 50% for cytologic analysis, 75% for ImmunoCyt, and 87% for both methods combined. The cytologic evaluation detected no G1, 1 (17%) of 6 G2, and 7 (100%) of 7 G3 tumors. ImmunoCyt detected 1 (33%) of 3 G1, 6 (100%) of 6 G2, and 5 (71%) of 7 G3 tumors. The sensitivity in the 32 urine samples obtained from the UT was 82% for cytologic analysis, 91% for ImmunoCyt, and 100% for both methods combined. Cytologic analysis detected all G2 and G3 (100% sensitivity) and no G1 tumors. ImmunoCyt detected 2 (100% sensitivity) of 2 G1, 4 (100%) of 4 G2, and 4 (80%) of 5 G3 tumors. The test specificity, calculated in 21 patients free of TCC, was 100% for cytologic analysis in voided and ureteral urine specimens and 95% and 100% for ImmunoCyt in voided and ureteral urine samples, respectively., Conclusions: The results of this preliminary study show that ImmunoCyt complements cytologic analysis in detecting UT-TCC, mainly because of its high sensitivity to low-grade TCC. The combination of cytologic testing and ImmunoCyt gives 100% sensitivity in detecting UT-TCC in UT urine samples.

Prothrombin is the precursor of thrombin, a central enzyme in coagulation. Autoantibodies to prothrombin are associated with thromboembolism, but the mechanisms by which the antibodies modulate the coagulation processes are not understood. We screened a panel of 34 monoclonal antibody light chains isolated from patients with multiple myeloma for prothrombinase activity by an electrophoresis method. Two light chains with the activity were identified, and one of the light chains was characterized further. The prothrombinase activity eluted from a gel-filtration column run in denaturing solvent (6 M guanidine hydrochloride) at the characteristic positions of the light chain dimer and monomer. A constant level of catalytic activity was observed across the width of the light chain monomer peak, assessed as the cleavage of IEGR-methylcoumarinamide, a peptide substrate corresponding to residues 268-271 of prothrombin. Hydrolysis of this peptide by the light chain was saturable and consistent with Michaelis-Menten-Henri kinetics (K(m) 103 microM; k(cat) of 2.62 x 10(-)(2)/min). Four cleavage sites in prothrombin were identified by N-terminal sequencing of the fragments: Arg(155)-Ser(156), Arg(271)-Thr(272), Arg(284)-Thr(285), and Arg(393)-Ser(394). The light chain did not cleave radiolabeled albumin, thyroglobulin, and annexin V under conditions that readily permitted detectable prothrombin cleavage. Two prothrombin fragments (M(r) 55 000 and 38 000), were isolated by anion-exchange chromatography and were observed to cleave a thrombin substrate, tosyl-GPR-nitroanilide. Conversion of fibrinogen to fibrin was accelerated by the prothrombin fragments generated by the light chain. These finding suggest a novel mechanism whereby antibodies can induce a procoagulant state, i.e., prothrombin activation via cleavage of the molecule.

In a comparative study, the in vivo metabolic profile of 99Tcm-anti-CD4 monoclonal antibodies (MAb) and Fab' fragments (direct thiol-reduction method) was investigated in rats with adjuvant arthritis. Plasma samples were obtained 1, 4 and 15 h following intravenous injection and urine was collected over 15 h. The composition of the radiolabelled molecules was analysed by gel filtration chromatography. The profile of the complete MAb was as follows. (1) Serum: a predominant peak of 150 kDa (complete MAb; approximately 80%); three minor peaks of 125, 100 and 50 kDa (presumably H2L1, H2 and H1 chains; 14%); and two small peaks of approximately 1500 and 300 Da (presumably 99Tcm-glutathione and Cys-99Tcm-Cys; 5%). (2) Urine: minor peaks of 125, 100 and 50 kDa (15%), major peaks of 1500 and 300 Da (50%), and an additional 25-kDa peak (30%). The profile of the Fab' was as follows. (1) Serum: three minor peaks of 150 kDa [conceivably F(ab')2 plus soluble-CD4], 110 kDa [F(ab')2] and 95 kDa (Fab' plus soluble-CD4; together 30%); a predominant peak of 55 kDa (Fab'; 61%); and two minor peaks of 1500 and 300 Da (8%). (2) Urine: predominantly a 55 kDa (16%) and 1500 and 300 Da peaks (74%). Also, the anti-CD4 Fab' showed higher urine excretion and lower plasma levels than the complete anti-CD4 MAb, but still more favourable tissue-to-blood ratios following scintigraphy of the arthritic joints. Thus, the complex metabolic profile of the anti-CD4 Fab' does not appear to interfere with specific targeting of the inflamed synovial membrane.

Background: Recently, urine flow cytometry (UFC) was introduced as a useful noninvasive tool for the immunological monitoring of renal allograft recipients. The presence of an active urine sediment as determined by UFC was found to be associated with acute rejection (AR) episodes., Methods: In the present study we assess the value of UFC in the setting of acute graft dysfunction. UFC was performed in 30 patients (32 events) at the time of admission to the hospital for the evaluation of rising creatinine (serum creatinine increment > or =0.6 mg/dl above baseline). UFC analysis was done blinded to the clinical diagnosis, and results were compared with the discharge diagnosis: AR, n=15; chronic rejection (CR), n=8; drug toxicity, n=4; urinary leak, n=2; recurrence of primary disease, n=1; lymphocele, n=1; and unknown, n=1., Results: The presence of at least 5% of HLA-DR-positive cells and intercellular adhesion molecule-1-positive cells was detected in 100% and 53%, respectively, of the samples associated with AR (P<0.01 vs. others). The specificity value for the diagnosis of AR was: 100% for the presence of intercellular adhesion molecule-1 or CD3-positive cells and 88% for the presence of interleukin-2 receptor-positive or HLA-DR-positive cells. Half of the samples associated with CR had CD14-positive cells (P=0.03 vs. others) with a specificity value of 87.3%. The samples associated with drug toxicity, urological problems, or recurrence of primary disease were remarkable for the lack of expression of the antigens studied., Conclusion: UFC can clearly differentiate AR from other causes of acute renal allograft dysfunction. HLA-DR is revealed to be the most sensitive and intercellular adhesion molecule-1 the most specific marker for AR. The presence of CD14-positive cells was highly suggestive of CR. Due to its objective nature, UFC should be considered in the evaluation of graft dysfunction.

The interference of buflomedil with the monoclonal and polyclonal EMIT d.a.u. amphetamine immunoassays was investigated. Urine samples collected from 20 patients taking 600 mg of buflomedil daily gave false positive results with the monoclonal EMIT d.a.u. assay, as did urine specimens collected 2 hours after the first oral dose of buflomedil. Conversely, no false positive results occurred with the polyclonal EMIT d.a.u. amphetamine assay. Urine samples with buflomedil added at concentrations greater than 100 mg/l gave false positive results with the monoclonal immunoassay. Buflomedil concentrations found in the patient urines (56-400 mg/l) failed to correlate to EMIT assay responses: this result suggests that one or more buflomedil metabolites, besides the unchanged drug, probably interfere in the monoclonal EMIT d.a.u. assay.

Mice bearing IgA hybridoma 'backpack' tumours have been used to demonstrate that secretion of a single monoclonal IgA can protect against mucosal infection, but the relevance of this model to normal IgA protection is not clear. The authors analysed the distribution of specific monoclonal and total antibodies in bile, local intestinal secretions, cervical-vaginal secretions, urine and serum of mice bearing anti-cholera toxin (CT) IgA and IgG backpack tumours, with and without bile duct ligation. Backpack tumours resulted in high levels of both anti-CT and total IgA or IgG in serum, and IgA (but not IgG) in bile. Secretions recovered by absorbent filter 'wicks' from mucosal surfaces throughout the intestines of backpack tumour mice contained significant concentrations of monoclonal anti-CT IgA, but total IgA levels were as in normal mice. Neither monoclonal nor total IgA levels on mucosal surfaces were altered by bile duct ligation. Furthermore, anti-CT monoclonal IgA levels in local intestinal secretions of backpack tumour mice were comparable to specific polyclonal IgA levels previously elicited by mucosal immunization with CT. Thus, IgA-mediated protection against enteric challenge in the backpack tumour model may be a valid predictor of protection provided by natural mucosal immunization in vivo. High monoclonal IgA levels in bile, urine and the female genital tract, however, may not reflect the situation in normal immunized mice.

High-resolution two-dimensional electrophoresis was used to analyze kappa-type monoclonal immunoglobulin light chains in urine of two patients with multiple myeloma. The patients were treated, remission lasted about 2.5 years. In the period of relapse of the disease, acid isoforms of kappa chains, pI < 4,95, which had not been present in the urine of these patients before, were found in urine of both patients. Kappa-type Bence-Jones protein in urine of one patient showed unusual behavior: It failed to precipitate in the range of 40-60 degrees C or on boiling.

RG 83852 is a murine monoclonal antibody that preferentially inhibits the high-affinity binding of epidermal growth factor (EGF) to its receptor. Since overexpression of EGF receptor has been implicated in some human malignancies, the antibody is under investigation as a potential anticancer agent. The present work characterized the tissue distribution and elimination of 131I-labeled antibody in rats following i.v. administration. 131I-RG 83852 was given in a 2.22 mg/kg dose to rats, and 4, 24, 48, and 72 h afterwards 131I activity excreted in the urine and feces and that present in various tissues was determined. The plasma contained the highest concentration of radioactivity at all times. At 4 h the plasma contained about 12% of the injected dose (ID)/ml, and radioactivity in this compartment accounted for almost 70% ID. The plasma elimination of 131I-derived activity occurred linearily at a rate of about 0.48% ID/h. Except in the thyroid, the concentration of 131I activity in all tissues was much lower than in the plasma (tissue-to-plasma ratio < or = 0.1). In the thyroid, accumulation of radioactivity (4% ID at 24 h) was presumably due to trapping of 131I released from the antibody as a result of biodegradation. The urinary excretion occurred at a rate of about 0.5% ID/h; the fecal excretion was minimal. The biodistribution results are consistent with the protein structure of the antibody. Based on the available disposition data, it is proposed that elimination of the antibody involves degradation, a process that follows zero-order kinetics, followed by excretion of the labeled product(s) in the urine.

Serum and urine samples from 161 cases of hairy cell leukemia (HCL) and 50 cases of chronic lymphocytic leukemia (CLL) were analyzed for monoclonal immunoglobulin (MIg) by using a combination of high-resolution protein electrophoresis, immunoelectrophoresis, and immunofixation. Quantitative immunoglobulin analysis also was performed on all serum samples. Monoclonal immunoglobulin, usually of low intensity, was identified in serum or urine in 26 (16.1%) cases of HCL compared with 27 (54%) cases of CLL. Forty-eight (29.8%) cases of HCL had an increase in one or more immunoglobulins; increases in IgG were the most frequent. In CLL, 48 (96.0%) cases had a decrease in one or more immunoglobulins, with decreases in IgG, IgA, and IgM in 76%, 68%, and 56% of the cases, respectively. The correlation between serum or urine monoclonal immunoglobulin light chain and the surface membrane light chain was 88% in CLL compared with 47.4% in HCL. These findings confirm previous observations of frequent polyclonal hyper-gamma-globulinemia in HCL, hypo-gamma-globulinemia in CLL, and weak monoclonal immunoglobulins in both disorders. The contrasting immunoglobulin abnormalities in HCL and CLL indicate distinctive biologic differences in these chronic B-cell leukemias.

Three MAb M2, B6, P1 (IgG1 type) against human urinary trypsin inhibitor (UTI), a glycoprotein with antiinflammatory properties, have been produced by hybridization of mouse myeloma cells P3o1 with spleen cells of immunized mice BALB/c. Competitive ELISA-examination of peroxidase conjugates of M2, B6, and P1 MAb in the presence of the trypsin binding domain shows the highest affinity of M2 antibody for this domain. On the basis of MAb M2 competitive ELISA of UTI concentration in urine is proposed. ELISA detectable changes in the UTI content of urine from patients with nephritis without renal failure can be considered as an early index of renal parenchyma damage.

All 241 patients with an apparently benign monoclonal gammopathy who were examined at the Mayo Clinic before Jan. 1, 1971, underwent prospective follow-up for 20 to 35 years (median, 22 years). Electrophoresis and immunoelectrophoresis of serum and urine specimens were performed periodically in an effort to determine the frequency of development of multiple myeloma, primary amyloidosis, macroglobulinemia, or other lymphoproliferative diseases. At follow-up, the patients were categorized into one of four groups: group 1 (benign)--46 patients (19%) who were alive and had a benign monoclonal gammopathy; group 2--23 patients (10%) who had a serum monoclonal protein value of 3 g/dl or more but did not require chemotherapy; group 3--113 patients (47%) who died without evidence of myeloma or related disorders; and group 4-59 patients (24%) in whom multiple myeloma (39), systemic amyloidosis (8), macroglobulinemia (7), or a malignant lymphoproliferative disease (5) developed at a median of 10, 9, 8, and 10 1/2 years, respectively, after detection of the monoclonal protein. Thus, in patients with an apparently benign monoclonal gammopathy, follow-up must be continued indefinitely because multiple myeloma, amyloidosis, macroglobulinemia, or related disorders occur in approximately a fourth of them.