Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome have recently been observed in patients undergoing interferon alpha (IFN-α) therapy. However, the relationship between disease and therapy has not been established, essentially because of concomitant treatment or previous bone marrow transplantation. We present a case of TTP developing during IFN-α therapy for chronic myelogenous leukemia. In this case, IFN-α seems to be the only etiological agent.

Translocation t(11;14)(q13;q32) and/or 11q13 rearrangements have been reported in various B cell immunoproliferative disorders. They appear to be frequent in mantle cell zone lymphoma (MZL) and rare in B-cell chronic lymphocytic leukemia (B-CLL). Discrimination between MZL and B-CLL is sometimes uncertain on the basis of morphology and immunophenotype. To evaluate the incidence of 11q13 rearrangements in B-CLL, purified B cells from 59 untreated patients were studied by cytogenetic methods after short term stimulated culture. Abnormalities at band 11q13 were found in 2 cases only. Fluorescent in situ hybridization (FISH) study confirmed del(11)(q13) in one case and showed translocation t(11;13) in another one. Thus this rearrangement appears to be very rare in B-CLL and its finding should lead to a careful search for the characteristic features of MZL, namely, morphology, the expression of CD5 without CD23, high density monotypic SIg, together with t(11;14) and/or bcl-1/IgH rearrangement.

In a prospective study in 65 untreated patients with early-stage B-cell chronic lymphocytic leukemia (B-CLL), serum monoclonal Igs (moIg) were evidenced in 80% of cases by a sensitive immunoblotting procedure. These low-abundance moIg were generally undetectable by immunoelectrophoresis and individual sera often contained several of them. Their kappa/lambda ratio was close to 1 instead of 2.8 for the lymphocyte surface Igs. A monoclonal IgM of the same light-chain type as the lymphocyte surface IgM was found in 26 sera only. The distribution of the heavy-chain classes and subclasses and light-chain types of the serum moIg was similar to those observed in aging (with a higher incidence and no correlation with age in B-CLL) and conditions with defective T-cell functions. Using a specific filter affinity- transfer assay, rheumatoid factors were detected in 58.5% of sera. However, homogeneous anti-IgG antibodies corresponding to a monoclonal IgM of the same light-chain type as the surface IgM were found in 10 patients only. These data suggest that the majority of discrete serum moIg in B-CLL are not secretion products of the leukemic clones and likely result from the immunodeficiency state inherent in the disease.

The in vitro proliferative response of purified B-chronic lymphocytic leukemia (B-CLL) lymphocytes cultured in the presence of soluble CD23 (sCD23) with or without IL2 was compared to the responses induced by phorbol 12-myristate 13-acetate (PMA), Staphylococcus aureus strain Cowan I (SAC), IL1, IL2, IL4, IL6 and the combination of IL2 and interferon (IFN) alpha or IFN gamma. As expected, B-CLL lymphocytes proliferated with PMA, SAC and IL2 with a clear enhancement of the IL2-induced response by IFN alpha or IFN gamma. They failed to proliferate in response to sCD23, IL1, IL4 or IL6 alone nor to the combinations of sCD23 and any of the 3 latter cytokines. However, sCD23 significantly increased the proliferation of B-CLL cells induced by IL2, suggesting a protective effect of sCD23 on apoptosis. Serum levels of sCD23 and CD23 membrane expression were high in every patient which is compatible with the hypothesis of an autocrine or paracrine activation loop. Detectable CD23 expression was lost in all cultures except for that stimulated by PMA. Only supernatants of PMA-stimulated cultures contained high sCD23 levels.

Chromosomal analysis of stimulated whole blood cells and purified B lymphocytes was performed in 13 stage A(0) and 1 stage C(IV) chronic lymphocytic leukemia (B-CLL) patients. Abnormal clones were found in 6 cases in purified B lymphocytes cultures and in a single one in whole blood cultures. In situ hybridization with a chromosome 12 probe was in accordance with the chromosomal analysis of purified B-CLL lymphocytes and not with the results obtained using whole blood culture. Cytogenetic analysis of isolated B cells is simple and sensitive. It enhances the detection of abnormal clones in B-CLL and applied to larger series of patients, it should allow a precise evaluation of the incidence of chromosomal abnormalities in CLL and of their clinical (prognostic) significance.

Cytogenetics of purified B lymphocytes and whole blood cultures were studied in 14 patients with B-CLL and fluorescence in situ hybridization (FISH) was performed on interphase cells in 12 of these cases in order to detect trisomy 12. Only one minor abnormal clone was found on whole blood cell cultures, clonal anomalies were found in a large proportion of mitoses of 6/14 cultures of purified B cells. FISH detected a trisomy 12 in a case, not found in whole blood cultures but found in 78% metaphases of cultures of purified B lymphocyte. This method may be as sensitive as FISH for the detection of trisomy 12 and improves the detection of clonal abnormalities in CLL.

A new combination regimen including chemotherapy and interferon was started in 1986 for the treatment of 24 chronic myelogenous leukaemia patients in chronic phase. Complete cytogenetic remission were noted in 10 patients and 6 of them are in sustained remission. The overall survival was 70% at 40 months. However, a minimal residual disease was detected in the 3 patients tested with the polymerase chain reaction. In addition no correlation was detected between the site of the breakpoint and response to therapy.

In view of the results achieved by others with interferons and also with low doses of Cytosine-arabinoside, we have treated 24 patients with IFN alpha 2a and Hydroxyurea for induction, with addition of low dose Ara-C during IFN maintenance therapy when the cytogenetic results were deemed insufficient. Complete hematological responses were obtained in 75% of the cases. Cytogenetic responses were noted in 83% of 12 previously untreated (complete or almost complete response in 3) and in 50% of previously treated patients (complete or almost complete response in 3 patients).

We report on 33 unpublished patients with clonal anomalies in chronic lymphocytic leukaemia. The literature was thoroughly reviewed in order 1) to quantify the frequency of anomalies found in chronic lymphocytic leukaemia and to give new status to the rarest, 2) to determine whether a given anomaly was an additional anomaly and/or a primary anomaly, and 3) to find out whether strong associations between different anomalies exist in this disease.

Three cases of M5 acute leukemia, 1 with a t(8;16)(p11;p13), 2 with variant translocations, both with a breakpoint at band 8p11, t(6;8)(q27;p11) and t(8;19)(p11;q13) are reported and 12 other published cases reviewed. This is a rare new entity, of variable but rather poor prognosis, seen from birth to 75 years of age, with several cases in infants. Leukemic cells, which often show conspicuous phagocytic activity on bone marrow smears, bear both monocytic and granulocytic markers in at least some cases. The best therapeutic regimen is not well-defined. The molecular basis of the disorder remains to be elucidated.