Craig E. Litz

B-cell lymphoproliferative disorders after bone marrow transplant. An analysis of ten cases with emphasis on epstein–barr virus detection by in situ hybridization

Ten patients with B‐cell lymphoproliferative disorders (BLPD) after bone marrow transplant were studied in a retrospective analysis of 81 specimens available from biopsy and autopsy material. Histologic review, immunophenotyping, and in situ hybridization (ISH) for Epstein–Barr virus (EBV) sequences were done. Sixty‐four specimens showed morphologic evidence of BLPD, demonstrating a heterogeneous spectrum with various degrees of plasmacytoid differentiation. Immunophenotypic evidence of clonality was found in six patients. The ISH detected EBV sequences in all ten patients, including 60 of the 64 specimens with morphologic evidence of BLPD. In addition, ISH identified EBV‐infected lymphoid cells in two of 17 sites without morphologic evidence of BLPD. These data demonstrate the utility of ISH for detecting EBV genome in this setting and provide further evidence for the etiologic role of EBV in the pathogenesis of BLPD.

Demonstration of clonality in neutrophils using FISH in a case of chronic neutrophilic leukemia

A patient previously diagnosed with chronic neutrophilic leukemia (CNL) was studied using fluorescent in situ hybridization (FISH) to determine clonality of neutrophils. By cytogenetic studies the patient’s blood and bone marrow had an 11q14 deletion and were negative for the Philadelphia (Ph) chromosome. FISH was performed on peripheral blood smears using probes for the bcr/abl translocation and a probe for 11q23 (MLL). The patient’s white blood cells were negative for the bcr/abl translocation; neutrophils and eosinophils, but not lymphocytes, were monosomic for the 11q23 probe indicating a clonal population within the neutrophil population.

Autologous bone marrow transplantation in acute myeloid leukemia: The University of Minnesota experience

PURPOSE To report the outcome of autologous bone marrow transplantation for patients with acute myeloid leukemia (AML) in first or greater complete remission (CR) treated by autologous bone marrow transplantation using two different preparatory regimens. METHODS AND MATERIALS Between September 1986 and August 1993, 75 patients with AML ranging in age from 6 months to 58 years underwent autologous bone marrow transplantation using previously harvested and frozen unpurged (n = 6) or 4-hydroperoxycyclophosphamide purged marrows (n = 69). Patients were in first CR (n = 44) or beyond first CR (n = 31). The preparative regimen consisted of 120 mg/kg of cyclophosphamide (CY) and 1320 cGy total body irradiation (TBI) in eight fractions over 4 days (CY/TBI) in 29 patients; and 16 mg/kg of Busulfan (BU) and 200 mg/kg of CY (BU/CY) in 46 patients. Thirty-five of these 75 patients (18 CY/TBI and 17 BU/CY) were part of a randomized trial comparing the two preparative regimens. RESULTS At 2 years, overall survival and disease-free survival (DFS) were 49% [95% confidence interval (C.I.) 37-61%] and 43% (95% C.I. 32-55%), respectively. Patients in first CR had a significantly better outcome than patients beyond first CR with an estimated 2-year DFS of 59% (95% C.I. 44-74%) vs. 21% (95% C.I. 5-36%, log-rank p = 0.0001), respectively. For patients conditioned with CY/TBI, the estimated 2-year DFS was 52% compared to 39% for BU/CY (log-rank p = 0.35). Estimated 2-year relapse rates were 44% vs. 56% (log-rank p = 0.40), respectively. For patients in first CR, no differences in DFS were observed between the two regimens (2-year estimates 69% vs. 55% log-rank p = 0.52). Patients beyond first CR had a significantly improved DFS with the CY/TBI regimen (2-year estimates of 38% vs. 7%, log-rank p = 0.04). No differences were found between the two regimens in terms of time to WBC engraftment, absolute neutrophil count of > 500, incidence of bacteremias, or median time to hospital discharge. Interstitial pneumonitis developed in two patients (one BU/CY, one CY/TBI) and venoocclusive disease developed in seven BU/CY patients (Fishers exact test p = 0.04). CONCLUSIONS For patients beyond first CR, the CY/TBI regiment provided a better outcome, with a significantly better disease-free survival and less venoocclusive disease. For patients in first CR, no significant difference between the two regimens was found. The high relapse rate, especially for patients with advanced disease, emphasizes the need for early transplantation and for new strategies to improve outcome.

Chronic myelogenous leukemia: Molecular diagnostic considerations

Chronic myelogenous leukemia (CML) is associated in 95% of cases with the Philadelphia chromosome (Ph1) by cytogenetic analysis. This acquired karyotypic abnormality is the product of a balanced translocation between the c-abl oncogene on chromosome 9 and the breakpoint cluster region (BCR) gene on chromosome 22. The resulting BCR/c-abl hybrid gene is actively transcribed and is considered essential in the pathogenesis of this disease. Southern blot- and polymerase chain reaction (PCR)-based tests for the detection of this rearrangement have been introduced over the last decade. These molecular tests are useful adjuncts to cytogenetic analysis in CML and may provide useful clinical information in certain instances.

2 Chronic lymphoproliferative disorders: Classification and diagnosis

The chronic lymphoproliferative disorders are morphologically, immunologically and clinically heterogeneous. Common features of these processes include T, B or natural killer cell immunophenotypes and terminal deoxy-nucleotidyl transferase negativity. The B cell lymphocytic disorders include B-chronic lymphocytic leukaemia, B cell prolymphocytic leukaemia, chronic lymphocytic leukaemia-prolymphocytic leukaemia, non-Hodgkins lymphoma (including mantle cell lymphoma) in leukaemic phase, hairy cell leukaemia and splenic lymphoma with villous lymphocytes. The T cell chronic lymphoproliferative disorders include prolymphocytic leukaemia, adult T cell leukaemia-lymphoma, large granulated lymphocyte leukaemia and Sezary syndrome. Occasionally, a lymphocytic proliferation is encountered that does not satisfy the morphological or immunophenotypical criteria for any of the above categories. These processes are best left unclassified.

Aberrant DNA Methylation of Genomic Regions Translocated in Myeloid Malignancies.

The mechanism of aberrant genetic recombinatorial events in neoplasia is vaguely understood. One hypothesis is that aberrant DNA methylation may in some way predispose genomic regions to recombination. Using the t(9;22) of chronic myeloid leukemia (CML) and the t(15;17) of acute promyelocytic leukemia (APL) as models, our laboratory and others have gathered data supporting this hypothesis. These data are reviewed.