L Debusscher

Immunological definition of acute minimally differentiated myeloid leukemia (MO) and acute undifferentiated leukemia (AUL).

Immunophenotyping has become an important tool in the diagnosis of acute leukemia for several reasons. Indeed the use of a standardized panel of monoclonal antibodies (MoAb) to B and T cells, and myeloid cells, as well as non lineage restricted antigens, permits allocation of more than 98% of acute leukemia to their respective lineage. In ALL, immunophenotyping has established a basis for precise and biologically oriented classification of the disease which may be of prognostic importance. In AML immunological markers are particularly important for identification of acute leukemia with minimal myeloid, erythroblastic or megakaryoblastic differentiation. Immunological markers also allow the identification of acute leukemias with minimal or aberrant marker expression, acute biphenotypic leukemia in which single cells coexpress different lineage associated markers and acute bilineage leukemia where there are two separate blast cell populations (usually lymphoid and myeloid). There is sometimes confusion in the literature about the definition of acute unclassifiable and acute undifferentiated leukemia. This is mainly due to misinterpretation of phenotypic data or to the lack of relevant lineage specific markers in these studies, especially for the detection of cytoplasmic antigens. Indeed, it is important to stress that in hematopoietic precursors, antigens detected by monoclonal antibodies first appear in the cytoplasm during early differentiation and are only expressed on the membrane later. This has been demonstrated not only for the T lineage (Cy CD3), the B lineage (CyCD22) but also for the myeloid lineage (CyCD13).(ABSTRACT TRUNCATED AT 250 WORDS)

The labelling index of marrow myeloblasts: A predictive test for relapse of acute non-lymphoblastic leukemia

Abstract The 3 HTdR labelling index of the marrow myeloblasts (MLI) was determined serially throughout complete remission (CR) of adult acute non-lymphoblastic leukemia (ANLL). 110 marrow samples were examined during 28 phases of CR obtained in 23 ANLL patients. The MLI was found to be between 20 and 66 in 100 determinations. An MLI below 20% was not found in well established complete remission but did occur near the end of 8 out of 20 CRs, 5–12 weeks (mean 7.6) before the reappearance of leukemic blasts in the marrow as judged by conventional microscopic examination. In those cases, the mean MLI was 13.2 (range 6–18). An MLI below 20% appears to be a reliable and early predictor of relapse of AML and permits the investigation of the clinical benefit of treating incipient relapse.

Influence of recombinant alpha and gamma interferons on the in vitro proliferation of myeloid and leukemic progenitors.

Abstract: We have compared the effect of alpha 2‐C and gamma recombinant interferons (rIFNs) on normal myeloid progenitors (N‐CFU‐GM), chronic myeloid leukemia (CML) progenitors (CML‐CFU‐GM) and leukemic progenitors (L‐CFU) of acute non‐lymphoblastic leukemia (ANLL) patients. Within 14 days of continuous exposure in culture, a dose‐dependent inhibition of CFU‐GM was seen for most normal subjects. Resistance to rIFNs was frequent in leukemic patients and even more in acute leukemia than in CML. Stimulation of clonogenic cell growth was seen for a minority of leukemic patients. When only the sensitive cases were considered, no difference in sensitivity was noticed between normal, CML and ANLL patients. A good correlation was observed between the activity or the lack of activity of alpha and gamma rIFNs.

De novo CD5-positive diffuse large B-cell lymphoma of the skin arising in chronic limb lymphedema

We report the case of a 79-year-old woman with a longstanding lymphedema of the right arm who developed a skin lymphoma involving the right wrist area. Microscopically, the lesion was composed of numerous centroblasts infiltrating both the dermis and the subcutaneous tissue. Phenotypic investigations showed expression of CD20, CD79a, and bcl-2 protein by neoplastic cells. In addition, these cells were CD5 positive. No expression of anaplastic large cell lymphoma kinase (ALK), CD10, CD23, CD30, CD43, bcl-6, cyclin D1, p53 or p16INK4a could be seen. Polymerase chain reaction (PCR) analysis demonstrated a clonal rearrangement of the genes coding for the kappa light chain of the immunoglobulin (Ig). No rearrangement of the genes coding for the Ig heavy chain, t(14;18) or t(11;14) chromosome translocations, or Epstein-Barr virus (EBV) genomic sequences could be found. The tumor was classified as stage IE and was first cured by complete surgical excision. Nineteen months later, a recurrence was noted in the right elbow area. This study further illustrates that lymphoma of the skin may complicate chronic limb lymphedema. Like most of the previously reported cases, this neoplasm belonged to the category of diffuse large B-cell lymphoma. However, it showed CD5 expression as a singular feature.

Effect of 4-hydroperoxycyclophosphamide on leukemic and normal human myeloid progenitor cells.

The sensitivity of myeloid progenitor cells from normal subjects (N-CFU-GM) and from leukemic patients in complete remission (LR-CFU-GM) to 4-hydroperoxycyclophosphamide (4-HC) were compared to the sensitivity of leukemic progenitor cells (L-CFU) to this drug. The results were expressed as the dose of 4-HC needed to kill 90% (TD 90) of the progenitor cells. The mean TD 90 were respectively for N-CFU-GM : 59 (+/- 11 S.E.M.) nM ml-1 and for L-CFU 79 (+/- 6 S.E.M.) nM ml-1. Thus, L-CFU were equally sensitive to 4-HC as N-CFU-GM. Moreover, the mean TD 90 for LR-CFU-GM was 87 (+/- 5 S.E.M.) nM ml-1. Thus, the sensitivity of N-CFU-GM and LR-CFU-GM did not differ significantly from that of L-CFU. These results are not encouraging for the use of 4-HC in vitro to eliminate the residual leukemic cells from autologous bone marrow of AML patients in complete remission. The sensitivity of L-CFU was modified neither by previous cytoreductive therapy (different from cyclophosphamide) nor by the time elapsed since diagnosis of AML.

Phase I-II evaluation of carminomycin in adults with acute leukemia.

Twenty courses of carminomycin were administered to 18 evaluable adult patients with acute leukemia (14 ANLL, 2 ALL, 2 CGL-BC). All but one received daily doses of 6-14 mg/m2 for 5 consecutive days. Two patients older than 60 yr had not prior chemotherapy and the others had refractory or relapsed disease. The median age was 60 yr. Three ANLL patients achieved complete remission for 8, 9 and 9 months respectively, with no maintenance therapy. None of these had proven clinical resistance to daunomycin and/or doxorubicin. Mucositis was dose-related and dose-limiting. Nausea and vomiting were rare. Alopecia was constant. Cardiac arrythmia was ascribed to carminomycin in two patients. One episode of cardiac failure seemed clearly drug-related and recovered with symptomatic treatment. In conclusion, encouraging antileukemic activity was observed with carminomycin in poor-risk patients. At doses up to 12 mg/m2 day X 5, extramedullary toxicity remained acceptable.

Factors influencing the release of leukemic blast cells from the marrow into the blood in human acute leukemia

Abstract The number of blood leukemic blast cells in human leukemias at the time of diagnosis has a prognostic value in terms of survival. In 5 patients studied, the blood blast count was found to be positively correlated with the number of blasts in the bone marrow and other proliferating and blast releasing sites. The present work indicates also that marrow blood cells in S, G 2 and M are not released into the blood. This was shown by blocking them in these phases of the cell cycle by different antileukemic agents. The larger size of the blasts in S, G 2 and mitosis as compared to the size in G 1 could partly explain the inability of S, G 2 and mitotic cells to egress from the marrow. Leukapheresis in one patient caused rapid recruitment of blasts in the blood. This recruitment was not due to release of blasts from the marrow.

Large Granular Lymphocyte Proliferative Disease - 21 Belgian Cases and Review of the Literature

We report the findings in 21 Belgian patients (12 males and 9 females, median age 61 years) with LGLPD. Symptoms at presentation included infection (n = 9), weight loss (n = 5), asthenia (n = 9), pruritus (n = 2) and arthralgia (n = 7). Four patients were asymptomatic. The main clinical findings were hepatomegaly (n = 5), splenomegaly (n = 8), lymph node enlargement (n = 3) and arthritis (n = 5). All patients had an increased LGL count associated with anemia (n = 12), neutropenia (n = 17), often less than 0.5.10(9)/L (n = 10) and thrombocytopenia (n = 6). Three patterns of lymphocyte surface markers were observed: CD3+CD4-8+ (14 patients), CD3+CD4-8+ (5 patients) and CD3+CD4+8- (1 patient). An abnormal karyotype was found in 2 patients. T-cell receptor gene was rearranged in all cases tested (9/9).