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In an 18-month period, 340 consecutive adult patients with acute leukemia were treated using a 7-day continuous infusion of Ara-C in combination with rubidazone, vincristine and prednisone (ROAP). Of 334 (96%) evaluable cases, 77% were 50 years of age or older. The complete remission (CR) rate was 51% with a standard error of 3%. After adjustment for known prognostic factors this overall CR rate is 10% higher than the predicted CR rate when compared to the last completed SWOG study which used adriamycin in combination with a similar regimen of Ara-C, vincristine, and prednisone. The CR rate in patients over 50 years of age was particularly noteworthy. Using rubidazone, the CR rate was 46.1% (116/256) compared to 37.4% (91/243) for the adriamycin study in this poorly responding age group. The median survival time achieved was 27 weeks. However, in the age groups 40-49 years and 50-59 years the median survival was 70 and 44 weeks, respectively.

We describe a newly recognized 40 kD FcR for IgG on human neutrophilic granulocytes. An mAb (IV3) developed against the IgG FcR of K562 cells, and specific as well for a 40 kD FcR on human monocytes and platelets, was found to purify by affinity adsorption a 40 kD protein from detergent lysates of surface-radioiodinated neutrophils. This protein, proteolytically degraded to 33 kD when purified in the absence of diisopropylfluorophosphate, is distinct from the 51-73 kD protein precipitated by the anti-neutrophil FcR mAb, 3G8, previously described by others. Complete inhibition of binding of rabbit IgG-coated erythrocytes to neutrophils was achieved only when both antibodies, IV3 and 3G8, were used. Fab fragments of IV3 were as effective inhibitors as the intact molecule. IV3 IgG or Fab fragments completely and selectively inhibited immune complex-mediated generation of superoxide by human neutrophils; superoxide generation by other stimulants was not abrogated by IV3. This antibody (IV3) bound also to human eosinophils and completely inhibited the binding of IgG-coated erythrocytes to eosinophils. IV3 appears to define the human homolog of the murine macrophage FcRII identified initially by mAb 2.4G2 and present in the mouse on both neutrophils and eosinophils.

Cytogenetic analysis of the leukemic cells from a 1-day-old baby with an acute myelomonocytic leukemia revealed them to contain a chromosome change of t(11;19)(q23;p13). Molecular studies using a 980 bp HindIII/HpaI digested v-ets probe showed no DNA rearrangements, deletions, or amplification in the leukemic cells, including the JH immunoglobulin and T-cell receptor (alpha or beta) genes. The findings indicate that the leukemic cells with t(11;19)(q23;p13) appear not to contain a transposition or rearrangement of the protooncogene Hu-ets-1 located at 11q23, as previously described in leukemic cells with t(4;11)(q21;q23) and t(9;11)(p22;q23). The leukemic cases with t(11;19)(q23;p13) studied by us showed a phenotype compatible with their myelomonocytic nature, although it is possible that other cases may have a lymphoid phenotype.

The 40 kD monocyte Fc receptor for IgG is capable of binding murine IgG1 and of supporting an IgG1 anti-T3 T lymphocyte proliferative response among approximately 80% of Caucasian individuals (responders), whereas the 40 kD Fc receptor on monocytes of the remaining individuals (nonresponders) is incapable of interacting with murine IgG1. By using a monoclonal antibody (mab IV3) that reacts with the 40 kD receptor, we found that the monocyte 40 kD receptors from responder and nonresponder individuals cannot be distinguished by either electrophoretic mobility on SDS-polyacrylamide gels, or by the number of receptors per cell as determined by indirect immunofluorescence. However, isoelectric focussing of the purified radioiodinated 40 kD receptor revealed that the monocyte receptor from all of four nonresponder individuals evaluated has a single distinctive pattern of multiple, regularly spaced bands, whereas the pattern of the 40 kD monocyte receptor from 11 responder individuals is of two sorts. One (seen in four of 11 responders) consists of multiple, regularly spaced bands that are asynchronous with the nonresponder pattern, and the other (seen in seven of 11 responders) consists of multiple bands that correspond in mobility to all of the bands of both of the other two patterns. The incidence of these three patterns suggests that the 40 kD Fc receptor is encoded by a single structural gene with two alleles, both of which are expressed.

A unique alloreactive human helper-inducer T-cell clone which reacts with the class I HLA antigen was characterized. The clone was derived from a mixed lymphocyte culture between cells from a HLA-A2-; B35,w51; Bw4,Bw6; Cw4,-; DR1,4; DQw1,-; DRw53 responder and a HLA-A2,3; B7,14; Bw6; Cw8,-; DR7,-; DQw2,w3; DRw52 stimulator. When screened against a panel of stimulator cells, this clone was found to have a specificity towards a stimulator HLA-B14 and consisted entirely of Leu-4, Leu-3, and 4B4 positive T cells, which is a T helper-inducer phenotype. Using monoclonal antibodies directed towards various monomorphic class I and II HLA epitopes in an inhibition experiment, it was found that both monoclonal antibodies w6/32 and 4E (recognizing class I monomorphic and HLA-B epitopes, respectively) inhibited proliferation. However, monoclonal antibodies BBm.1 and L227 (directed against beta 2-microglobulin and Ia-like molecule, respectively) had no inhibitory effect. Functional evaluation of this clone demonstrated helper activity on the proliferation of MLC response. The helper-induction effect on MLC cultures remained intact following irradiation of the clone for either 500 or 2000 rad suggesting that helper function of the clone was radiation resistant. The helper activity of this clone was MHC nonrestricted since it enhanced proliferation of the original responder and stimulator MLC as well as third and fourth party individuals. By CTLL cell line proliferation assay, this clone was found to release IL-2. When assayed (day 1 to 7) for class II HLA products expression following stimulation, HLA-DRw53 was consistently expressed by the clone. However, HLA-DR1, DQw1 were found to be expressed simultaneously on day 2 through day 7 and HLA-DR4, DQw3 on day 2 and 3. These data demonstrate, for the first time, the generation of a class I specific helper-inducer T-cell clone in MLC response.

Ph-positive acute myeloblastic leukemia (AML) developing in a treated case of Wegener's granulomatosis is reported. The patient was a 70-year-old white male who received cyclophosphamide (150 mg/day) starting in July 1978; in May 1984 the patient was diagnosed as having AML, following a diagnosis of myelodysplastic syndrome lasting 3 months. Cytogenetic study of bone marrow cells at the diagnosis of the myelodysplastic syndrome revealed a standard Ph translocation in addition to numerical chromosome changes [i.e., 45,XY, -5, -7, -8, +19, +mar/45,XY, -5, -7, -8, +19, +mar,t(9;22)(q34;q11]). The events in this case suggest a strong possibility of the Ph-positive AML being a secondary disease related to prior cyclophosphamide therapy.

Cytogenetic studies were performed on two patients with myelodysplastic syndromes. One patient was a 68 year old Japanese male in whose bone marrow cells two translocations were established, i.e., t(4;11)(q13;q23) and t(11;17)(q11?;q11), as well as other karyotypic changes (-6,-18,15p+). The other patient was a 74 year old white male whose bone marrow cells showed six marker chromosomes, i.e., der(5),t(5;17)(q12;q11), der(6),t(6;5)(q27;q22), der(8),t(8;11;?)(q11;q11----q23;?), der(11),t(11;?)(q11;?), an isochromosome of the long arm of chromosome #8, and a small G-group sized marker chromosome of unknown origin. Though the translocation patterns in the abnormal cells in these two cases were different, the breakpoints of the marker chromosomes were almost the same, i.e., 11q11, 11q23, and 17q11. Also, changes of chromosome #6 were observed; the first case showed monosomy 6 and the second a 6q+ marker chromosome. In these two cases of myelodysplastic syndromes, common sites of chromosome breakage and reunion of 11q23 and 17q11 were close to recently established sites of human cellular oncogene homologs, c-ets (11q23) and c-erbA (17q21----24). These associations draw attention to a possible relationship between chromosome changes in myelodysplastic syndromes and oncogene (or other gene) activation and/or dysfunction.

Amsacrine was administered to 73 evaluable patients with previously treated malignant lymphoma in the Southwest Oncology Group. The drug was administered iv every 3 weeks at a dose of either 90 mg/m2 to poor-risk patients (38 patients) or 120 mg/m2 to good-risk patients (35 patients) in 500 ml of 5% dextrose in water over 1 hour. The overall complete plus partial response rate is 16% (12 responses among 73 evaluable patients), with a response duration of 1-33 months. The dose-limiting toxic effect was myelosuppression, with leukopenia in 29 patients and thrombocytopenia in 18 patients. Our experience in the Southwest Oncology Group demonstrates the activity of amsacrine in malignant lymphoma.

To determine incubation conditions that result in optimal in vitro killing of human tumor cells with monoclonal antibody and complement, variables affecting the killing of cultured human neuroblastoma cells with monoclonal antibody 6-19 and baby rabbit complement were studied. Neuroblastoma target cells were stained with the fluorescent dye Hoechst 33342, which enables rapid, sensitive detection of surviving cells in conjunction with trypan blue exclusion. Maximal cell lysis was obtained at an antibody concentration of 5-10 micrograms/ml. Greater than 5 logs of cell kill were obtained with appropriate treatment conditions. No antigenic modulation was detected. Complement activity was found to be the factor which limited the extent of cell kill. Specific cell lysis increased with increasing concentration of complement. As the reaction with antibody coated cells proceeded, complement activity was depleted. This resulted in the greatest cell kill occurring during the first 10-20 min of treatment. Generation of factor(s) inhibitory to complement activity was also found. However, the effect of inhibition on limiting the extent of cell kill was much less significant than the effect of complement depletion. When compared to a single incubation of the same total duration, the reduction in complement activity with duration of incubation resulted in greater killing by multiple brief incubations with fresh complement. The depletion of complement was found to increase at a greater cell concentration. This resulted in greater proportional survival as neuroblastoma cell concentration increased. Depletion of complement activity by aggregated monoclonal antibody was found to decrease cytotoxicity. This evaluation may provide a framework for optimization of target cell destruction using complement and other monoclonal antibodies and target cells.

The role of the low avidity 40,000 dalton receptor for IgG (Fc gamma R) present on K562 and U937 cells in sensitivity to natural killing (NK) was studied by using a murine monoclonal antibody (mAb) specific for the 40,000 dalton Fc gamma R (alpha Fc gamma R mAb). Pretreatment of K562 target cells with intact alpha Fc gamma R mAb or its Fab fragment or anti-transferrin receptor (alpha TFR) mAb partially blocked in a dose-dependent manner, NK activity to K562 cells. However, combined pretreatment with alpha Fc gamma R and alpha TFR mAb completely blocked NK activity against K562 targets. As compared with K562 cells, lower levels of NK were elicited against Molt-4, U937, HL-60, and Daudi targets. Although NK activity to Molt-4 targets was not affected by alpha Fc gamma R mAb, it was fully prevented by pretreatment with alpha TFR mAb. In contrast, NK to U937 cells was not influenced by alpha TFR mAb, but it was strongly inhibited by alpha Fc gamma R mAb. The resistance of 3H-TdR-prelabeled adherent HEp-2 cells to natural cell-mediated cytotoxicity was not affected by either mAb. Lectin-dependent cell-mediated cytotoxicity (LDCC) against HEp-2 cells due to the presence of concanavalin A, and was completely abrogated by pretreatment of the targets with alpha TFR mAb, but was unaffected by alpha Fc gamma R mAb. By use of the flow cytometer, a significant correlation was detected between the relative expression of 40,000 dalton Fc gamma R and the susceptibility to NK, whereas the expression of TFR was discordant from NK sensitivity. As determined in the single cell cytotoxicity assay alpha Fc gamma R mAb reduced the frequency of target binding effector cells without affecting the number of dead bound targets. This pattern of inhibition was found against both K562 and U937 targets. Alternatively, alpha TFR mAb inhibited both binding and killing of K562 and Molt-4 targets. Because pretreatment of HEp-2 cells with alpha TFR mAb did not influence conjugate formation, the blocking of LDCC to HEp-2 cells by alpha TFR mAb can be related to post-binding events. These data show that although both the 40,000 dalton Fc gamma R and the TFR can be target structures for NK cell recognition, the TFR may also play an important role in the post-binding events.

Three previously unreported mouse monoclonal antibodies are described. All three bind to cultured human neuroblastoma cells from six of six cell lines, but do not detectably bind to human bone marrow cells. The two IgG2a monoclonal antibodies bind to greater than 98% of the cultured cells from each cell line, bind to six of six human neuroblastoma tumors by immunoperoxidase histochemistry, and are cytotoxic with complement to cultured human neuroblastoma cells but not to human bone marrow granulocyte-macrophage colony-forming cells.

A variable T lymphocyte proliferative response to murine IgG1 anti-T3 monoclonal antibodies, in which most North American Caucasians respond whereas a minority do not, is well established. This is most likely the result of a genetic polymorphism manifested by 1) the inability of the monocyte 40-kDa IgG FcR of some individuals to bind murine IgG1, and 2) a distinctive trimorphic pattern on IEF of the monocyte 40-kDa FcR, one form being seen in all individuals who do not respond and another form (or a combination of both forms) being seen in those who do respond. We have evaluated the IEF patterns of the platelet 40-kDa FcR and find that in every individual tested the pattern for platelet FcR correlates with that seen for the monocyte 40-kDa FcR pattern. Furthermore, the platelets of those individuals whose "nonresponder" monocyte 40-kDa FcR did not mediate a murine IgG1 anti-T3 response did not respond with an aggregation reaction to murine IgG1 immune complexes (opsonized E). In contrast, platelets from donors possessing "responder" monocytes displayed positive "aggregation" responses to E coated with murine IgG1 antibody. However, the platelet FcR structural polymorphism described earlier did not correlate with the donor-specific variability in capacity of platelets to respond functionally to aggregated human IgG described in an earlier paper. Rather, the variation in capacity of platelets from individual donors to respond functionally to aggregated human IgG was related to the quantitative expression of platelet FcR. These data indicate that the molecular mechanisms responsible for the platelet 40-kDa FcR structural polymorphism are quite different from the mechanisms governing the variation in quantitative expression of the receptor.

Three cases with chromosome changes involving bands 7p14 or 7p15 and 11p15 are described: one was a Japanese female with an acute myelomonocytic leukemia, the second was a white female with a 10-year history of paroxysmal nocturnal hemoglobinuria who developed a myelodysplastic syndrome, and the third was a patient with Ph-negative atypical chronic myelogenous leukemia with trisomy 8 and a chromosome change involving bands 7p14 and 11p15. These cases possibly indicate that the t(7;11)(p14 or p15;p15) change may characterize a subset of human nonlymphocytic neoplasia.

A case of a non-T, non-B acute lymphoblastic leukemia with a translocation between chromosomes #1 and #9 is described. The breakpoints in these chromosomes were determined to be at bands 1q23 and 9p22, respectively. The breakpoint in chromosome #1 was at the same site as that in a subgroup of acute lymphoblastic leukemia with t(1;19), and the breakpoint in #9 was the same as that in t(9;11)(p22;q23) in acute monoblastic leukemia. We discuss the possible association between these chromosome bands (1q23, 9p22, 11q23, and 19p13) and the morphologic features of the leukemic cells. The breakpoint in chromosome band 1q23 may be specifically associated with acute lymphoblastic leukemia.

Rats were given enemas of Gastrografin in two strengths, Renografin--76, and Tween--80 in a 10% dilution. There were no deleterious effects on the colons with these media used in volumes to fill the colon. Severe changes resulted from volumes which produced overdistention.

Evidence has recently been presented that a 40,000 dalton membrane sialoglycoprotein (p40) shared by monocytes and granulocytes serves as the human platelet receptor for aggregated IgG. We now report that the platelets of normal donors exhibit stable quantitative differences in the expression of this receptor molecule, as determined by flow cytometry using fluorescent staining with murine monoclonal antibody to p40 (mab IV.3). These inter-donor differences were reproducible on repeated testing over at least 4 mo. In concurrent assays, the binding of mab IV.3 to each donor's platelets was highly correlated with the binding of heat-aggregated human IgG, also assayed by flow cytometry. The biological relevance of this quantitative variation in IV.3 binding is suggested by its reproducible correlation with platelet responsiveness to aggregated IgG measured by aggregometry. Such stable quantitative variation in platelet Fc receptor expression among individual humans could contribute to differences in severity of certain pathologic processes initiated by IgG-containing immune complexes.

We have described a patient with thymoma, hypogammaglobulinemia, pernicious anemia, and malignant schwannoma. Review of the literature yielded only one other case of the triad of thymoma, hypogammaglobulinemia, and pernicious anemia. We propose that autoimmunity was the common etiology for the coexistence of thymoma, hypogammaglobulinemia, and pernicious anemia in our patient.

One-hundred and fifty-three subjects who were irradiated in infancy for an alleged enlarged thymus and 51 controls were studied to quantify the phenotypically different subpopulations of peripheral blood lymphocytes and immunoglobulins. These subjects were selected from a larger cohort which has been followed prospectively since the early 1950s. Previous studies of this cohort have shown a radiation dose-related increased risk of thyroid carcinomas and adenomas in the irradiated group as well as a recent excess of various extrathyroid neoplasms. In this substudy, no significant differences in lymphocyte subpopulations or immunoglobulin levels were observed between the irradiated and control groups. These findings support a hypothesis that the radiation-related excess of neoplasms in this cohort may have resulted from direct cellular damage with subsequent mutations rather than impaired immune function.

We have utilized monoclonal antibodies against the two IgG Fc receptors (p40 and p72) of U937 cells to stimulate the release of superoxide. The monoclonal antibody (mAb) specific for p40 (IV3) has been described elsewhere. A murine IgG1 mAb specific for the high affinity p72 Fc receptor (designated mAb FcR32 or simply mAb 32) bound to the same p72 precipitated by Sepharose-human IgG as shown by preclearing experiments and by identical isoelectric focussing patterns. Binding of mAb 32 to p72 was independent of the Fc region of the antibody since Fab' fragments of mAb 32 affinity adsorbed p72. The binding of both mAb 32 and human IgG1 to the intact U937 cell was not reciprocally inhibitory, indicating that mAb 32 does not interfere with the ligand binding site of p72. mAb 32 bound to human monocytes, U937, and HL60 cells, but not to granulocytes or lymphocytes. U937 cells cultured in gamma-interferon and 1,25-dihydroxycholecalciferol generated superoxide when incubated with mAb 32 or IV3 followed by cross-linking with F(ab')2 anti-murine Ig. Incubation with mAb 32 or IV3 alone or with 3 of 5 other anti-U937 mAbs cross-linked with anti-murine Ig did not result in superoxide generation. Immune complex-mediated superoxide production was inhibited 80% by IgG, but not by mAb 32 or IV3.

A modified zymosan preparation was used to probe the interaction of particulate stimuli with human neutrophils (PMNs). After extraction with alkali and detergent, the zymosan particles retained their ability to be opsonized in serum and to stimulate PMNs. Serum-treated zymosan (STZ) induced dose-dependent superoxide (O2-) production and membrane potential depolarization in the range of 1 to 10 mg/mL of STZ. The rate and extent of secretion of lysozyme and beta-glucuronidase were also dose-dependent in the range of 1 to 10 mg/mL of STZ. Cytochemical studies using nitroblue tetrazolium, however, showed that 92% of PMNs were stimulated to produce O2- at 0.1 mg/mL of STZ. The dose response of O2- production induced by STZ is therefore due to increasing O2- production by individual PMNs and not to the stimulation of more PMNs to produce O2-. Evidence for O2- production was found only in the area of PMN-zymosan contact, suggesting a mechanism for the graded responses of PMNs treated with particulate stimuli. In order to determine the nature of the dose dependence of depolarization (a measure of PMN activation), PMNs equilibrated with the fluorescent probe 3,3'-dipentyloxacarbocyanine were analyzed by flow cytometry. The results demonstrate that STZ induces a dose-dependent depolarization of the membrane potential of individual PMNs. These results also demonstrate that increasing concentrations of STZ can induce increasing PMN responses even when all of the PMNs have been activated. These results are consistent with the hypothesis that receptor-mediated particulate stimulation of PMNs is a phenomenon that results in graded PMN responses.

Expression of differentiation markers in common acute lymphoblastic leukemia (cALL) cells from 25 patients was compared with subpopulations of normal common ALL antigen (CALLA) (CD10)-positive bone marrow lymphoid cells (cBMLs). In cBML, CD10 intensity is positively correlated with CD34 (MY10) and terminal transferase (TdT) expression and inversely correlated with common leukocyte antigen (CLA), CD20 (B1), and ctyoplasmic mu chain (Cmu) expression. In cALL, CD10 density was inversely correlated with CLA and Cmu expression and strongly correlated with CD34 expression as in cBML. In contrast to cBML, TdT and CD20 expression were not related to CD10 density in cALL. Furthermore, cALL TdT intensity measured by enzyme immunoassay was not related to expression of CD10, CLA, or CD34, but was positively correlated with CD20 expression. Cmu expression in cALL was inversely correlated with expression of CD34 and positively correlated with CLA as in cBML, but showed no association with TdT intensity or CD20 expression in contrast to the relationship found in cBMLs. Analysis of TdT intensity and Cmu expression in sorted subpopulations of cells from individual patients that were positive or negative for CD34, CD20, or CD10 was consistent with the data obtained by comparison of cells from different patients. These results indicate that from patient to patient and within individual patients, cALL cells express the markers CD34, CLA, CD10, and Cmu in a coordinated fashion similar to cBMLs, but demonstrate differences in expression of TdT and CD20 with respect to the marrow cells considered their normal counterparts. The cALL cells that are CD34 positive show increased expression of CD10 and are less likely to be CLA or Cmu positive, suggesting that they may represent a phenotypically less differentiated form of cALL than does CD34-negative cALL.

The murine IgG2a monoclonal antibody 6-19 binds to a wide variety of nonhematopoietic cells including human marrow-derived stromal cells but does not bind to marrow or peripheral blood cells. We studied the effects of this antibody and rabbit complement on marrow cells. Fibroblast colonies were eliminated from light density marrow cells by a single incubation with monoclonal antibody 6-19 and complement. The growth and composition of granulocytic and erythroid colonies were unaffected. Specific complement mediated cytotoxicity of the antibody was confirmed on passaged human fibroblasts derived from marrow (more than 99.6% of fibroblasts are killed by a single treatment). Similar results were obtained with human umbilical cord endothelial cells. In addition, such treatment abolished the initiation of Dexter culture stroma. Incubation of bone marrow cell suspensions with this antibody and complement will allow the study of stroma-free marrow cells in long-term liquid cultures.

The Southwest Oncology Group did a limited institutional pilot study of the combination of doxorubicin and ifosfamide in the treatment of previously treated adult patients with acute leukemia. Thirty-four patients received one or two courses of the combination. All patients had received prior chemotherapy and 32 had received prior anthracycline chemotherapy. Three patients died before their responses could be fully evaluated. Fourteen patients achieved complete remission (41%) and one patient achieved partial remission. The complete remission rate was 27% for patients with acute myeloblastic leukemia (myelomonoblastic leukemia, monoblastic leukemia, and erythroleukemia) and 89% for patients with acute lymphocytic and undifferentiated leukemia (ALL). Toxic effects included severe hematologic reactions in 33 of 34 patients, hematuria in six patients, altered sensorium in one patient, and congestive heart failure in one patient. The safety of the combination was established and toxic side effects of this therapy were tolerable. The 89% complete remission rate for previously treated patients with ALL suggests that the combination of doxorubicin and ifosfamide may be particularly effective in ALL.

Three classes of FcR have been defined on human myeloid cells by their reactivity with mAb; FcRI (mAb 32); FcRII (mAb IV3); and FcRIII (mAb 3G8). We have quantitated the expression of each FcR on human myeloid leukemia cells and cell lines (KG-1, HL-60, U937, and K562). Detailed analysis of FcR surface expression is provided for the U937 cell line after exposure to CSF and cytokines. Increased expression of FcRI and FcRII occurred at 72 h in cells exposed to GCT or Mo cell line-conditioned medium as well as to medium from PHA-treated mononuclear cells. The augmentation of FcRII required protein synthesis and was diminished by a neutralizing antibody to granulocyte-macrophage CSF. We also show that fractions containing natural granulocyte CSF or granulocyte-macrophage CSF as well as r-granulocyte and r-granulocyte-macrophage CSF are capable of inducing FcRII on these cells, whereas other cytokines such as IL-1 and IL-2, TNF-alpha, INF-gamma and macrophages CSF failed to do so.

We have studied the apparent kinetic parameters of the ecto-nucleotide triphosphatase from CLL B lymphocytes and compared them to blood and tonsillar B and T cells. The Vmax of the ecto-ATPase activity in CLL B lymphocytes, was 65 +/- 10 fmol Pi/cell per 30 min compared to 37 +/- 2.1 in blood B lymphocytes, and 8.5 +/- 1.7 in blood T lymphocytes. The ATPase of membranes prepared from CLL, tonsillar B and T, and blood T lymphocytes had a relationship among the cell types similar to that seen in intact cells. However, no difference in the km for ATP, .17 mM, or the km for magnesium, .15 mM was found in the ecto-ATPase of CLL lymphocytes as compared to blood or tonsillar B cells. The ectoenzyme of CLL cells hydrolyzed GTP, ITP, CTP, and UTP as well as ATP. Further, ATP added to an enzyme assay containing an alternative nucleotide did not result in increased phosphate release. Nucleotide acceptance of blood B and T lymphocytes was very similar to that of CLL B cells. ATP inhibited phosphate release when present in excess of magnesium in both CLL and blood B lymphocytes. These data indicate that there is greater ectonucleotide triphosphatase activity in tonsillar and blood B lymphocytes, including CLL, as compared either to blood or tonsillar T lymphocytes. However, CLL cells showed no qualitative difference from blood or tonsillar B cells in ectonucleotidase activity. Thus, the higher activity in CLL cells is "B cell-like" and might reflect, also, their maturation stage or monoclonal origin.

The cause of the abnormal T lymphocyte subsets reported in healthy homosexual men is not known. Frequent sexually transmitted infections including human T cell lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) are possible causes. To determine if the T lymphocyte subsets were abnormal in this population in an area without endemic acquired immune deficiency syndrome (AIDS), T lymphocyte subsets of 52 homosexual men in Rochester, New York, were enumerated, and evidence of infections known to cause these abnormalities was sought. Unlike the findings in previous reports, relative numbers of T helper and T suppressor cells and helper/suppressor T cell ratios were normal. Prevalence of cytomegalovirus infection (86 percent) was similar to that found in analogous populations, but only 9 percent had seropositive results for HTLV-III/LAV. Men with serologic evidence of nonprimary cytomegalovirus disease had lower helper/suppressor T cell ratios (1.5 +/- 0.2 versus 2.2 +/- 0.2; p less than 0.01). Hence, despite frequent infections with cytomegalovirus and other sexually transmitted pathogens, T cell subsets are normal in homosexual men in an area without endemic AIDS. Therefore, HTLV-III/LAV is primarily responsible for the T cell abnormalities observed elsewhere.

An electrophoretic method has been applied to characterize specific fibrinogen and fibrin degradation products (FDP) in 135 serum samples from 59 consecutive patients having a positive latex agglutination test for serum FDP in the evaluation of consumption coagulopathy. In 20 of 135 positive samples, the principal fibrinogen derivatives present were not degradation products of fibrinogen or fibrin but were instead residual fibrinogen or fibrin monomer and polymers (FFMP) due to incomplete clotting. Heparin exposure was common in patients with positive FDP tests occurring in 29 of 59 patients (49%) with 81 of 135 samples (60%). Heparin exposure by parenteral administration or catheter was significantly correlated with a false positive serum FDP test because of residual FFMP occurring in 19 of 81 (23%) samples from heparin-exposed patients but in only 1 of 54 (2%) samples from patients without exposure (P less than 0.005). Treatment of the false positive samples with reptilase, an enzyme unaffected by heparin, resulted in complete removal of the residual FFMP, and in vitro experiments demonstrated that heparin-containing plasma samples could be completely clotted with either reptilase or protamine sulfate plus thrombin. Survey of 20 regional laboratories showed that only 10% used reptilase or protamine sulfate to prepare serum if heparin exposure had occurred and that this was done in only 22 of 5,049 (0.4%) of samples in the last calendar year. Greater attention should be given to proper preparation of serum from heparin-exposed patients, and physicians should be aware of the possibility of falsely positive or falsely elevated serum FDP tests in evaluation of consumption coagulopathy in heparin-exposed patients.