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We present the case where immune thrombocytopenia (ITP) and essential thrombocythemia (ET) sequentially appeared in the space of twenty-one years of follow-up. Impaired platelet production is present in both diseases, but clinical presentation and treatment are different. On the basis of this case history a possible role of autoimmunity as a predisposing factor to myeloproliferation has been discussed. [ABSTRACT FROM AUTHOR]

The CXCL12 [chemokine (C-X-C motif) ligand 12] is a member of the CXC family of chemokines and interacts with its CXCR4 receptor. The CXCL12/CXCR4 axis is involved in regulation of proliferation, survival and trafficking of hematopoietic stem cells, including B lymphocytes and disruption within this signaling pathway has been implicated in pathogenesis of chronic lymphocytic leukemia (CLL). The aim of this study was to determine a potential association of the CXCL12 rs1801157 G > A polymorphism with susceptibility to CLL, the disease course and efficacy of therapy. Also, expression of the CD74 and CD38 proteins on B cells was analyzed in relation to clinical parameters and genotyping results. A total of 124 patients with CLL and 75 healthy controls were studied. CXCL12 genotyping was performed using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method. The CD74 and CD38 surface expression was determined using flow cytometry. There was a significantly increased frequency of the A allele and AA genotype in CLL patients compared with control group ( P < 0.001 in both cases). In addition, the A allele was overrepresented among patients with worse response to therapy in comparison to other genotypes ( P < 0.001). On the contrary, patients carrying the A allele displayed lower grade of the disease at diagnosis more frequently than patients homozygous for the G allele ( P = 0.037). Moreover, the AA homozygosity correlated with lower CD74 expression on B cells ( P = 0.007). In conclusion, data from this study indicate that the CXCL12 rs1801157 G > A polymorphism may affect CLL development, disease progression as well as response to treatment. [ABSTRACT FROM AUTHOR]

Introduction Limited data are available on optimal prophylaxis regimens of factor IX ( FIX) replacements for patients with haemophilia B. Aim This multicentre, open-label study evaluated the efficacy and safety of once-weekly prophylaxis with nonacog alfa compared with on-demand treatment in adolescent and adult patients. Methods Males aged 12-65 years with moderately severe to severe haemophilia B ( FIX:C ≤ 2%) were eligible for enrolment. Patients received on-demand treatment for 26 weeks, followed by once-weekly prophylaxis of 100 IU kg−1 for 52 weeks. The primary efficacy end point was the annualized bleeding rate ( ABR). Secondary end points included response to on-demand treatment, the number of infusions used to treat bleeding events, and the incidence of less-than-expected therapeutic effect ( LETE). FIX:C was measured on day 1 and at weeks 26 and 78. Results Mean (± SD) ABR was lower during prophylaxis vs. on-demand treatment [3.6 (±4.6) vs. 32.9 (±17.4) events, respectively; P < 0.0001]. The majority (88.4%) of bleeding events had excellent or good responses upon the first infusion; 82.1% of events responded to the first infusion. No incident of LETE occurred. No thrombotic events or FIX inhibitors were reported. Eight of 17 FIX:C approximately 1 week after dosing were >2 IU dL−1 (min-max of 2.13-10.39 IU dL−1). Conclusions Once-weekly prophylaxis of 100 IU kg−1 was associated with lower ABR compared with on-demand treatment in adolescents and adults with moderately severe to severe haemophilia B. Once-weekly prophylaxis was well tolerated, with a similar safety profile as that reported during the on-demand treatment period. Residual FIX:C may be supportive of effectiveness. [ABSTRACT FROM AUTHOR]

Genes involved in regulation of the nuclear factor - kappa B ( NF-κB) pathway are suggested to play a role in the pathogenesis of acute myeloid leukaemia ( AML). The present study aimed to assess the association between the NF-κB1, TRAF3 and TLRs genes single nucleotide polymorphisms ( SNPs) and disease susceptibility as well as progression in patients with AML. For this purpose 62 patients and 126 healthy individuals were genotyped for NF-κB1 (rs28362491), TRAF3 (rs11160707; rs12147254), TLR2 (rs201786064), TLR4 (rs4986790; rs4986791) and TLR9 (rs5743836; rs187084) alleles. Three SNPs were found to be associated with the risk for the AML development. The TRAF3 (rs12147254) AA homozygosity ( RR = 2.770, P = 0.0392), TLR9 (rs5743836) C wild-type allele (RR = 2.542, P = 0.0096) as well as TLR9 (rs187084) T allele ( RR = 13.396, P < 0.0001) and its homozygosity ( RR = 11.805, P < 0.0001) were more frequent among patients with AML than healthy individuals. The associations of the rs187084 SNP were significant for both sexes. Moreover, patients who relapsed were more frequently characterized with the presence of the rs187084 TLR9 TT genotype ( P = 0.045) or the rs12147254 TRAF3 A variant ( P = 0.066). In conclusion, polymorphisms within the TLR9 and TRAF3 genes are associated with predisposition to AML and may affect the progression of the disease in the Polish population. [ABSTRACT FROM AUTHOR]

The association of single-nucleotide polymorphisms ( SNPs) of B-cell activating factor ( BAFF)/a proliferation-inducing ligand ( APRIL) system with B-cell chronic lymphocytic leukemia (B- CLL) have been suggested, therefore, we investigated 20 SNPs of BAFF, APRIL, BAFF-R, transmembrane activator and calcium modulator and cyclophilin-ligand interactor ( TACI), B-cell maturation antigen ( BCMA) genes and the risk and outcome of B- CLL in 187 patients and 296 healthy subjects as well as ligand-receptor gene × gene interactions. Although the obtained P-values for all 20 SNPs did not reach statistical significance for this study (α = 0.003), the high value of the global chi-squared statistic (χ2df = 38 = 52.65; P = 0.0586), and obtained values of odds ratio indicate that rs9514828 ( BAFF), rs3803800 ( APRIL) and rs4985726 ( TACI) may be associated with the risk of B- CLL. We observed that the B- CLL patients with the genotype rs9514828CT/ rs11570136AA were diagnosed with the disease 12 years later than the whole group of patients in this study. [ABSTRACT FROM AUTHOR]

Factor VIII (FVIII) concentrates have revolutionized the treatment of patients with haemophilia A. Concerns over the transmission of viral infections through these products have been addressed through stringent, donor-screening procedures and robust antiviral manufacturing steps. Bio Products Laboratory has developed a high-purity FVIII product with von Willebrand factor, Optivate. Its safety, tolerability and efficacy as prophylaxis and treatment of bleeds have been established in long-term studies. Seventy previously treated patients with severe haemophilia A, with ≥20 exposure days, were recruited into two long-term, multicentre, open-label studies. The protocols were virtually identical. Patients received Optivate either prophylactically or on-demand. A mean of 159.0 EDs were experienced over 11 320 infusions. Under both conditions, Optivate was well tolerated. Only 10% of patients experienced a treatment-related adverse event; the most commonly reported were headache (4% of patients) and dizziness (3% of patients). The mean number of bleeds/patient over the 2 year treatment period was 23.5 during prophylactic use and 70.4 during on-demand use. In patients treated prophylactically, clinical responses to breakthrough bleeds were rated by physicians as excellent or good and as very helpful or helpful by patients in 95% of bleeds. Clinical responses for on-demand patients were rated as excellent or good by physicians and helpful or very helpful by the patients for 91% of bleeds. There were no viral transmissions or inhibitors. The studies confirm the clinical efficacy and safety of Optivate in both prophylactic and on-demand management of patients with haemophilia A. [ABSTRACT FROM AUTHOR]

Optivate is a high purity factor VIII/von Willebrand factor (FVIII/VWF) concentrate, which is manufactured using two antiviral processes: solvent/detergent and terminal dry heating (80°C for 72 h). A multicentre, non-randomized open-label study in 15 patients was conducted to test the pharmacokinetics (PK) of Optivate. PK variables were analysed for the patients' prior FVIII product (PK1), their first dose of Optivate (PK2) and at 3 months therapy (PK3). Mean non-compartmental half-lives (h) were 14.1, 12.4 and 12.1, respectively ( P = 0.45), mean clearances (mL h kg) were 3.6, 3.2 and 3.1, respectively ( P = 0.051), MRTs (h) were 19.0, 17.3 and 17.4, respectively ( P = 0.39) and mean AUC (h IU mL) were 14.3, 15.4 and 16.6, respectively ( P = 0.051) and mean AUC (h IU mL) were 15.9, 16.4 and 17.9, respectively ( P = 0.18). The recovery data from this PK study was aggregated with recovery data collected from another study, with similar design but devoid of the other PK measurements. A total of 309 recoveries were conducted in 70 patients. The overall mean recovery per subject across 27 Optivate batches was 2.7 IU dL per IU kg. There were no clinical differences between Optivate and other FVIII products, and except for volume of distribution (Vd), no statistically significant differences were seen with respect to any of the other PK variables, or in recovery between weeks 0 and 12. Therefore, the PK of FVIII is not affected by the processes used to manufacture Optivate, which can be expected to be effective in the management of patients with haemophilia A. [ABSTRACT FROM AUTHOR]

Bone morphogenetic proteins (BMPs) are multifunctional cytokines which belong to transforming growth factor β (TGF β) superfamily. They regulate proliferation, differentiation, and apoptosis in a variety of cells including hematopoietic cells. BMPs act because of binding to two types of serine/threonine kinase receptors: BMP type I receptors (IA and IB) and BMP type II receptor. Deregulation of BMPs signaling pathways has been reported in some of human cancers, but the role of BMPs in hematopoietic malignancies remains unknown. The aim of our study was to examine the percentage of expression of BMPs receptors on lymphocytes of patients with B-cell chronic lymphocytic leukemia (B-CLL). A total of 46 patients with B-CLL (27 men and 19 women) and 10 healthy persons were evaluated. Freshly isolated mononuclear cells were incubated with antibodies against BMPs receptors: BMPRIA, BMPRIB, and BMPRII and examined in 2-color flow cytometry. On cells of patients with B-CLL, the percentage of expression of BMP RIA, BMP RIB, and BMP RII was significantly higher than in normal cells of the control group. The percentage of the expression of BMP RIA and BMP RIB was higher in patients with advanced stage of disease. [ABSTRACT FROM AUTHOR]

The pathophysiology of Non-Hodgkin’s lymphoma (NHL) is still unknown and clinical course is very unpredictable. Many cytokines, including interleukin-10 (IL-10), play a role in the perpetuation of this disease. The IL-10-producing capability has been found to be influenced by the IL-10 gene promoter polymorphisms. The aim of the present study was to assess whether any of IL-10 (−1082 A/G, −819 C/T and −592 A/C) genotypes prevails in Polish patients with NHL and whether IL-10 promoter polymorphisms may be associated with less or more favourable course of the disease. IL-10 gene promoter polymorphisms were assessed in 105 individuals, including 55 NHL patients and 50 ethically matched controls. The frequency of the IL-10 low-producing −1082 AA homozygous genotype was significantly higher in patients with aggressive NHL as compared with patients with indolent forms of the disease (0.57 vs 0.28, P < 0.05) and controls [0.57 vs 0.32, odds ratio (OR) = 2.69, P < 0.05]. Also, the presence of the ACC genotype was more frequently detected among patients with more aggressive disease than in those with indolent forms (0.74 vs 0.47, P < 0.05) and healthy controls (0.74 vs 0.42, OR = 3.69, P < 0.05). In multivariate analyses, the AA homozygosity (OR = 6.33, P < 0.05) and ACC genotype (OR = 3.57, P = 0.05) appeared as independent risk factors of more aggressive manifestation of NHL in addition to the elevated lactate dehydrogenase 480 level. Although no direct association was found between IL-10 promoter polymorphisms and NHL, IL-10 (−1082) AA homozygosity and IL-10 ACC genotype were found to be associated with unfavourable prognosis in patients with NHL. [ABSTRACT FROM AUTHOR]

B-cell chronic lymphocytic leukaemia (B-CLL) is a lymphoproliferative disorder characterized by clonal expansion of B lymphocytes. The present study aimed to determine whether there is an association between the polymorphic features located within the promoter/enhancer region of tumour necrosis factor-α ( TNFA) gene and susceptibility to B-CLL. TNFA (−308 G/A) promoter single nucleotide polymorphism (SNP) was determined by polymerase chain reaction with sequence-specific primers (PCR-SSP) using commercial oligonucleotides. No significant association was found between the distribution of TNFA alleles and B-CLL in Polish patients with B-CLL. Our single centre results were compared with other literature data and combined in a cumulative analysis employing the Mantel–Haenszel method. Among 183 B-CLL patients, 47 (26%) were carrying TNFA*2 allele and this allele was present in 98 out of 348 controls (28%). Also, the results of the Mantel–Haenszel test did not show a significant correlation [Mantel-Haenszel estimate of approximate relative risk (RMH) = 0.86, P = 0.294]. These results suggest that TNFA ( –308) alleles are not involved in the predisposition to the development of B-CLL. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To evaluate the efficacy and toxicity of cladribine (2-chlorodeoxyadenosine, 2-CdA), cytarabine (Ara-C), and granulocyte-colony stimulating factor (G-CSF) (CLAG) regimen in refractory acute myeloid leukemia (AML) in the multicenter phase II study. Methods: The induction chemotherapy consisted of 2-CdA 5 mg/m[sup 2] , Ara-C2 g/m[sup 2] , and G-CSF. In the case of partial remission (PR), a second CLAG was administered. Patients in complete remission (CR) received two consolidation courses based on HD Ara-C, mitoxantrone or idarubicine, with or without 2-CdA. Results: Fifty-eight patients from 11 centers were registered; 50 primary resistant and eight early relapsed (CR1 < 6 months). CR was achieved in 29 (50%) patients, 19 (33%) were refractory, and 10 (17%) died early. Forty of 50 primary resistant patients received daunorubicin (DNR) and Ara-C as the first-line induction therapy (DA-7), 10 received additional 2-CdA (DAC-7). The CR rates after CLAG were 58% and 10%, respectively in each group (P = 0.015). Five of six patients with myelodysplastic syndrome (MDS)/AML achieved CR. Hematologic toxicity was the most prominent toxicity of this regimen. The overall survival (OS, 1 yr) for the 58 patients as a whole, and the 29 patients in CR were 42% and 65%, respectively. Disease-free survival (DFS, 1 yr) was 29%. Only first-line induction treatment with DA-7 significantly influenced the probability of CR after CLAG. None of the analyzed factors significantly influenced DFS and OS. Conclusion: CLAG regimen has significant anti-leukemic activity and an acceptable toxicity in refractory AML. The addition of 2-CdA to the first-line induction treatment may worsen the results of salvage with CLAG. The high CR rate in patients with MDS preceding AML deserves further observation. [ABSTRACT FROM AUTHOR]

The role of angiogenesis in multiple myeloma (MM) pathogenesis is well established. Angiogenesis is linked to the functional state of endothelial junctions that are modulated by the growth and activation of endothelial cells. CD146 and vascular endothelial-cadherin (VE-cadherin) are cell adhesion molecules localized at the endothelial junction. The aim of the study was to assess sVE-cadherin and sCD146 serum levels in MM patients. Forty-six untreated patients with MM were included in this study. In addition, 23 of 46 patients were analyzed again in partial remission after initial chemotherapy. Twenty-two samples from healthy volunteers were evaluated as the control. There was no significant difference in sCD146 level between MM patients and the control (511 ± 177.2 vs. 460.9 ± 156.9 ng/ml respectively). In untreated MM patients, sVE-cadherin level was significantly higher than in the control (1.36 ± 0.55 vs. 0.63 ± 0.56 ng/ml respectively; P < 0.05). In untreated MM patients, sVE-cadherin level was significantly higher than in MM patients in partial remission (1.36 ± 0.55 vs. 0.5 ± 0.33 respectively; P < 0.05). sVE-cadherin but not sCD146 serum level was increased in untreated MM patients and decreases after chemotherapy in patients in partial remission. VE-cadherin may reflect intensity of angiogenesis in MM and may be useful in prognosis of response to treatment. [ABSTRACT FROM AUTHOR]

Despite enormous progress and development of high-throughput methods in genome-wide mRNA analyses, data on the erythroid transcriptome are still limited, even though they could be useful in medical diagnostics and personalized therapy as well as in research on normal and pathological erythroid maturation. Although obtaining normal and pathological reticulocyte transcriptome profiles should contribute greatly to our understanding of the molecular bases of terminal erythroid differentiation as well as the mechanisms of the hematological diseases, a basic limitation of these studies is the difficulty of efficient reticulocyte RNA isolation from human peripheral blood. The restricted number of possible parallel experiments primarily concern healthy individuals with the lowest number of reticulocytes in the peripheral blood and a low RNA content. In the present study, an efficient method for reticulocyte RNA isolation from healthy individuals and hemolytic anaemia patients is presented. The procedure includes leukofiltration, Ficoll-Paque gradient centrifugation, Percoll gradient centrifugation, and negative (CD45 and CD61) immunomagnetic separation. This relatively fast and simple four-stage method was successfully applied to obtain a reticulocyte-rich population from healthy subjects, which was used to efficiently isolate the high-quality RNA essential for successful NGS-based transcriptome analysis., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Intensive induction chemotherapy using anthracycline and cytarabine backbone is considered the most effective upfront therapy in physically fit older patients with acute myeloid leukemia (AML). However, outcomes of the standard induction in elderly AML are inferior to those observed in younger patients, and they are still unsatisfactory. As addition of cladribine to the standard induction therapy is known to improve outcome in younger AML patients. The present randomized phase II study compares efficacy and toxicity of the DAC (daunorubicin plus cytarabine plus cladribine) regimen with the standard DA (daunorubicin plus cytarabine) regimen in the newly diagnosed AML patients over 60 years of age. A total of 171 patients were enrolled in the study (DA, 86; DAC, 85). A trend toward higher complete remission (CR) was observed in the DAC arm compared to the DA arm (44% vs. 34%; P = .19), which did not lead to improved median overall survival, which in the case of the DAC group was 8.6 months compared to in 9.1 months in the DA group (P = .64). However, DAC appeared to be superior in the group of patients aged 60-65 (CR rate: DAC 51% vs. DA 29%; P = .02). What is more, a subgroup of patients, with good and intermediate karyotypes, benefited from addition of cladribine also in terms of overall survival (P = .02). No differences in hematological and nonhematological toxicity between the DA and DAC regimens were observed., (© 2017 Wiley Periodicals, Inc.)

In this double-blind, Phase 2 study, 220 patients with relapsed/refractory multiple myeloma were randomly assigned 1:1:1 to receive placebo (N = 72), tabalumab 100 mg (N = 74), or tabalumab 300 mg (N = 74), each in combination with dexamethasone 20 mg and subcutaneous bortezomib 1·3 mg/m 2 on a 21-day cycle. No significant intergroup differences were observed among primary (median progression-free survival [mPFS]) or secondary efficacy outcomes. The mPFS was 6·6, 7·5 and 7·6 months for the tabalumab 100, 300 mg and placebo groups, respectively (tabalumab 100 mg vs. placebo Hazard ratio (HR) [95% confidence interval (CI)] = 1·13 [0·80-1·59], P = 0·480; tabalumab 300 mg vs. placebo HR [95% CI] = 1·03 [0·72-1·45], P = 0·884). The most commonly-reported treatment-emergent adverse events were thrombocytopenia (37%), fatigue (37%), diarrhoea (35%) and constipation (32%). Across treatments, patients with low baseline BAFF (also termed TNFSF13B) expression (n = 162) had significantly longer mPFS than those with high BAFF expression (n = 55), using the 75th percentile cut-off point (mPFS [95% CI] = 8·3 [7·0-9·3] months vs. 5·8 [3·7-6·6] months; HR [95% CI] = 1·59 [1·11-2·29], P = 0·015). Although generally well tolerated, PFS was not improved during treatment with tabalumab compared to placebo. A higher dose of 300 mg tabalumab did not improve efficacy compared to the 100 mg dose. Nonetheless, BAFF appears to have some prognostic value in patients with multiple myeloma., (© 2016 John Wiley & Sons Ltd.)

The purpose of this study is to assess the safety and efficacy of the combination of ofatumumab and bendamustine in patients with previously untreated or relapsed chronic lymphocytic leukemia. Patients received IV ofatumumab (cycle 1: 300 mg day 1 and 1,000 mg day 8; cycles 2-6: 1,000 mg on day 1 every 28 days) and IV bendamustine 90 mg m(-2) (previously untreated) or 70 mg m(-2) (relapsed) on days 1 and 2 of each 28-day cycle, for up to 6 cycles. Forty-four previously untreated and 53 relapsed patients were enrolled. Median age was 62.5 years (previously untreated) and 68 years (relapsed); relapsed patients had received a median of 1 (range 1-11) prior therapy. The investigator-assessed overall response rate was 95% (43% complete response [CR]) for the previously untreated, and 74% (11% CR) for the relapsed patients. The regimen was well tolerated with 89% (previously untreated) and 85% (relapsed patients) receiving all 6 cycles. No unexpected toxicities were reported. Grade 3/4 events occurred in 57% of previously untreated, and 72% of relapsed patients. At ∼29 months' follow-up, the median progression-free survival (PFS) was not reached for the previously untreated population, and the 28-month PFS estimate was 72.3%. The median PFS for the relapsed population was 22.5 months (95% CI: 14.0-27.3 months). The combination of ofatumumab and bendamustine was well tolerated and effective in these previously untreated or relapsed populations. Am. J. Hematol. 91:900-906, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

The importance of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for survival outcomes in patients with acute myeloid leukemia (AML) currently remains unclear. The study aimed to compare measures of clinical treatment for patients with AML in CR1 (the first complete remission) with or without being subjected to allo-HSCT. These consisted of leukemia-free survival (LFS), overall survival (OS), cumulative incidence of relapse (CIR), and non-relapse mortality disease (NRM). Subjects were 622 patients, median age of 44, forming part of the prospective, randomized, and multicenter clinical Polish Adult Leukemia Group trials during 1999-2008. The Mantel-Byar approach was used to assess allo-HSCT on survival endpoints, accounting for a changing transplant status. Undergoing allo-HSCT significantly improved the LFS and OS for the entire group of patients with AML in CR1, along with the DAC induction subgroup and for the group with unfavorable cytogenetics aged 41-60. The CIR demonstrated that allo-HSCT reduced the risk of relapse for patients with AML in CR1 and those with an unfavorable cytogenetic risk. In addition, the NRM analysis showed that allo-HSCT significantly reduced the risk of death unrelated to relapse for the entire group of AML patients in CR1 and aged 41-60. The allo-HSCT treatment particularly benefitted survival for the AML in CR1 group having an unfavorable cytogenetic prognosis., (© 2015 Wiley Periodicals, Inc.)

Between January 1992 and January 1999, we treated 378 B-chronic lymphocytic leukaemia (CLL) patients with cladribine (2-CdA), and 255 of the patients were also treated with prednisone. A total of 194 patients were previously untreated, and 184 had relapsed or refractory disease after previous other therapy. Complete response (CR) was obtained in 111 (29.4%) and partial response (PR) in 138 (36.5%) patients, giving an overall response (OR) rate of 65.9%. CR and OR were achieved more frequently in patients in whom 2-CdA was a first-line treatment (45.4% and 82.5% respectively) than in the pretreated group (12.5% and 48.4% respectively) (P < 0.0001). The median duration of OR for previously untreated patients was 14.7 months and for pretreated patients 13.5 months (P = 0.09). The median survival evaluated from the beginning of 2-CdA treatment was shorter in the pretreated group (16.3 months) than in the untreated group (19.4 months) (P < 0.0001). A total of 117 (63.9%) patients died in the pretreated group and 63 (32.6%) in the untreated group. In pretreated patients, 2-CdA + prednisone (P) and 2-CdA alone resulted in similar OR (51.0% and 45.0% respectively; P = 0.4). In contrast, in untreated patients, 2-CdA + P produced a higher OR (85.4%) than 2-CdA alone (72.1%) (P = 0.04). Infections and fever of unknown origin, observed in 91 (49.4%) pretreated and 74 (38.1%) untreated patients (P = 0.03), were the most frequent toxic effects. Our results indicate that 2-CdA is an effective, relatively well-tolerated drug, especially in previously untreated CLL.

We have examined the production of interferon (IFN) gamma by peripheral blood mononuclear cells (PBMC) in 22 patients with Hodgkin's disease (HD) in active phase of the disease, 12 patients in clinical remission and 16 healthy subjects. The level of IFN gamma in supernatants of PBMC stimulated for 72 h with anti-CD3 monoclonal antibody (mAb), measured by sandwich enzyme immunoassay (ELISA) was 50.4 +/- 2.3 U/ml in active phase; 137.0 +/- 7.4 U/ml in clinical remission patients; and 520.0 +/- 10.0 U/ml in the controls; the difference between the groups was statistically significant. Co-stimulation with interleukin-2 (rIL-2) markedly amplified production of IFN gamma. The mean levels were 220.8 +/- 7.0 U/ml, 590.7 +/- 3.6 U/ml and 2111.1 +/- 17.3 U/ml in active phase HD, clinical remission and controls, respectively, the difference between groups was statistically significant. The patients showed the same kinetic pattern as healthy individuals. Our results indicate that patients with HD have severely impaired TCR/CD3 activation pathway resulting in significantly depressed IFN gamma response to anti-CD3 mAb and anti-CD3 + rIL-2 in vitro stimulation and provide support for the possible clinical use of IFN gamma as an immunopotentiating agent in patients with HD.