J. Amess

Risk and Clinical Implications of Transformation of Follicular Lymphoma to Diffuse Large B-Cell Lymphoma

PURPOSE To study the clinical significance of transformation to diffuse large B-cell lymphoma (DLBCL) in patients with follicular lymphoma (FL). PATIENTS AND METHODS From 1972 to 1999, 325 patients were diagnosed with FL at St Bartholomews Hospital (London, United Kingdom). With a median follow-up of 15 years, progression occurred in 186 patients and biopsy-proven transformation in 88 of the 325. The overall repeat biopsy rate was 70%. RESULTS The risk of histologic transformation (HT) by 10 years was 28%, HT not yet having been observed after 16.2 years. The risk was higher in patients with advanced stage (P = .02), high-risk Follicular Lymphoma International Prognostic Index (FLIPI; P = .01), and International Prognostic Index (IPI; P = .04) scores at diagnosis. Expectant management (as opposed to treatment being initiated at diagnosis) also predicted for a higher risk of HT (P = .008). Older age (P = .005), low hemoglobin level (P = .03), high lactate dehydrogenase (P < .0001), and high-risk FLIPI (P = .01) or IPI (P = .003) score at the time of first recurrence were associated with the diagnosis of HT in a biopsy performed at that time. The median survival from transformation was 1.2 years. Patients with HT had a shorter overall survival (P < .0001) and a shorter survival from progression (P < .0001) than did those in whom it was not diagnosed. CONCLUSION Advanced stage and high-risk FLIPI and IPI scores at diagnosis correlate with an increased risk of HT. This event strongly influences the outcome of patients with FL by shortening their survival. There may be a subgroup of patients in whom HT does not occur.

Myeloablative therapy with autologous bone marrow transplantation as consolidation therapy for recurrent follicular lymphoma.

PURPOSE To assess myeloablative therapy with autologous bone marrow transplantation (ABMT) in younger patients with follicular lymphoma in the hope of prolonging remission duration and survival. PATIENTS AND METHODS Since June 1985, 64 patients with follicular lymphoma have received cyclophosphamide (CY) 60 mg/kg x 2 and total-body irradiation (TBI) 2 Gy x 6 supported by ABMT as consolidation of second or subsequent remission. The marrow mononuclear cell (MNC) fraction was treated in vitro with three cycles of the monoclonal antibody (MAb) anti-CD20 and baby rabbit complement before cryopreservation. At the time of treatment, 34 patients were in complete remission (CR), and 30 had residual disease present. RESULTS The median time to engraftment was 28 days (range, 15 to 46) for both a neutrophil count greater than 0.5 x 10(9)/L and a platelet count greater than 20 x 10(9)/L. Engraftment did not occur in one patient who died at 12 weeks, and three patients (excluded from the range) have had delayed recovery (> 6 months) of RBCs and platelets. Fifty two patients are alive; three died as a consequence of the transplant procedure, two died in remission from other causes, and seven died of recurrent lymphoma. There was a significant correlation between survival and the total number of episodes of treatment required during the course of the illness (< or = to three v > three, P = .01). With a median follow-up duration of 3 1/2 years, 35 patients continue in remission between 1 and 8 years, and 24 have developed recurrent lymphoma, five with evidence of transformation to high-grade histology. Freedom from recurrence did not correlate with the time from diagnosis, the number of previous treatments, the presence or absence of residual disease at the time of treatment, or during which specific remission the treatment was given (second v > second). However, comparison with an age-matched, remission-matched, historical control group shows a significant advantage in favor of treatment with CY plus TBI plus ABMT (P = .001); currently, there is no difference in survival. CONCLUSION These results are encouraging, although preliminary; it remains to be established whether this treatment prolongs survival.

Thrombo-embolic disease after splenectomy for hereditary stomatocytosis.

Nine cases of hereditary stomatocytosis (HSt) are presented which show documented thrombotic complications after splenectomy. In three cases, patients became severely ill with pulmonary hypertension and a fourth developed portal hypertension. One unsplenectomized affected adult relative had suspected but unconfirmed thrombotic pathology; the six other affected unsplenectomized adults did not. Since splenectomy is of only limited therapeutic benefit in stomatocytosis, it should be not be performed without careful consideration. A tendency to iron overload, even without hypertransfusion and irrespective of splenectomy, is evident in many of these patients.

Genome-wide analysis of acute myeloid leukemia with normal karyotype reveals a unique pattern of homeobox gene expression distinct from those with translocation-mediated fusion events.

Gene expression profiles were determined from presentation peripheral blood and bone marrow samples of 28 patients with acute myeloid leukemia (AML). Hierarchical clustering sorted the profiles into separate groups, each representing one of the major cytogenetic classes in AML [i.e., t(8;21), t(15;17), inv(16), 11q23, and normal karyotype]. Statistical group comparison identified genes whose expression was strongly correlated with these chromosomal classes. Moreover, the normal karyotype AMLs were characterized by distinctive up‐regulation of certain members of the class I homeobox A and B gene families, implying a common underlying genetic lesion. These data reveal novel diagnostic and therapeutic targets and demonstrate the potential of microarray‐based dissection of AML.

Mutations of CEBPA in acute myeloid leukemia FAB types M1 and M2

CEBPA encodes the transcription factor C/EBPα and is specifically up‐regulated during granulocytic differentiation. The gene is mutated in approximately 20% of patients with acute myeloid leukemia (AML) FAB type M2 and occurs in the absence of the t(8;21). In much the same way as specific translocations are associated with a particular AML FAB type, the identification of non‐random associations of gene mutation with karyotype or FAB type may be helpful in elucidating the molecular basis of certain forms of leukemia. To confirm these initial findings, 99 patients with AML FAB type M1 or M2 were screened for CEBPA mutations by use of a PCR–single‐strand conformational polymorphism and sequencing approach. Nine CEBPA mutations were identified in eight patients. The mutations were clustered toward the COOH terminal of the protein and occurred exclusively in the intermediate cytogenetic risk group (8/64, 12.5%). Two patients with biallelic mutation, one homozygous for 1137Ins (57 bp) and another with two CEBPA mutations, 1096Ins (27 bp) and 363Ins (GGCC), were observed. There was no evidence for deletion of this region in the other six mutated samples analyzed by fluorescence in situ hybridization with a BAC clone spanning the CEBPA locus. CEBPA mutation status was not demonstrated to be of prognostic importance in this patient group, although this may reflect the selection and size of the AML population studied. In conclusion, mutation of CEBPA is a recurrent finding in AML and appears specific to the intermediate cytogenetic risk group patients.

Tositumomab and Iodine I 131 Tositumomab for Recurrent Indolent and Transformed B-Cell Non-Hodgkin’s Lymphoma

PURPOSE An open-label phase II study was conducted at two centers to establish the efficacy and safety of tositumomab and iodine I 131 tositumomab at first or second recurrence of indolent or transformed indolent B-cell lymphoma. PATIENTS AND METHODS A single dosimetric dose was followed at 7 to 14 days by the patient-specific administered radioactivity required to deliver a total body dose of 0.75 Gy (reduced to 0.65 Gy for patients with platelets counts of 100 to 149 x 10(9)/L). Forty of 41 patients received both infusions. RESULTS Thirty-one of 41 patients (76%) responded, with 20 patients (49%) achieving either a complete (CR) or unconfirmed complete remission [CR(u)] and 11 patients (27%) achieving a partial remission. Response rates were similar in both indolent (76%) and transformed disease (71%). The overall median duration of remission was 1.3 years. The median duration of remission has not yet been reached for those patients who achieved a CR or CR(u). Eleven patients continue in CR or CR(u) between 2.6+ and 5.2+ years after therapy. Therapy was well tolerated; hematologic toxicity was the principal adverse event. Grade 3 or 4 anemia, neutropenia, and thrombocytopenia were observed in 5%, 45%, and 32% of patients, respectively. Secondary myelodysplasia has occurred in one patient. Four patients developed human antimouse antibodies after therapy. Five of 38 assessable patients have developed an elevated thyroid-stimulating hormone; treatment with thyroxine has been initiated in one patient. CONCLUSION High overall and CR rates were observed after a single dose of tositumomab and iodine I 131 tositumomab in this patient group. Toxicity was modest and easily managed.

Loss of CD20 expression following treatment with rituximab (chimaeric monoclonal anti‐CD20): a retrospective cohort analysis

A retrospective analysis of CD20 expression following rituximab for B‐cell non‐Hodgkins lymphoma demonstrated a significant change in immunophenotype in 6/25 (24%) patients with persistent bone marrow (BM) infiltration. In three out of six patients, the B cells were uniformly CD20−/CD79α+, consistent with frank loss of CD20 expression. In the remaining three cases, the BM infiltrate was predominantly (> 80%) CD20−/CD79α+. Two of the former but none of the latter three cases achieved a clinical response. In three further cases, the post‐treatment BM infiltrate was composed entirely of benign or reactive CD3+ T cells. Frank loss of CD20 was not seen in 25 post‐treatment lymph node biopsies. Immunophenotyping is therefore an important adjunct in the diagnosis of BM infiltration following rituximab.

Durable Remissions of Myelodysplastic Syndrome and Acute Myeloid Leukemia After Reduced-Intensity Allografting

PURPOSE To evaluate the use of reduced-intensity (RI) conditioning with allogeneic hematopoietic stem cell transplantation (HSCT) from HLA-identical family donors in patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). PATIENTS AND METHODS Sixteen patients (median age, 54 years; range, 37 to 66 years) underwent RI-HSCT using a conditioning regimen of fludarabine 25 mg/m2 daily for 5 days and either cyclophosphamide 1 g/m2 daily for 2 days (14 patients) or melphalan 140 mg/m2 for 1 day (two patients). The median number of CD34+ cells and CD3+ cells infused per kilogram of recipient weight was 4.5 x 106 (range, 1.8 to 7.3 x 106 cells) and 2.9 x 108 (range, 0.1 to 9.6 x 108 cells), respectively. RESULTS There was no transplant-related mortality (TRM) within 100 days of HSCT. Grade 1 to 2 acute graft-versus-host disease (GVHD) occurred in three patients, but neither grade 3 nor grade 4 disease was observed. Chronic GVHD occurred in 10 patients. One patient had cytomegalovirus (CMV) reactivation but did not develop CMV disease. With a median follow-up of 26 months (range, 15 to 45 months), 11 patients are alive (nine in continuous complete remission and one in complete remission after a second transplantation), and five have died (four from disease progression and one from bone-marrow aplasia induced by cyclosporine withdrawal). The 2-year actuarial overall and event-free survival rates were 69% (95% confidence interval [CI], 40% to 86%) and 56% (95% CI, 30% to 68%), respectively. CONCLUSION This strategy of RI-HSCT resulted in reliable engraftment with low incidence of acute GVHD and TRM. Durable remissions were observed in patients with MDS and AML consistent with a graft-versus-leukemia effect.

Demonstration of an immune‐mediated mechanism of penicillin‐induced neutropenia and thrombocytopenia

Severe neutropenia may be a more common complication of high‐dose penicillin therapy than previously recognized. This report describes five such patients, one of whom also had thrombocytopenia. The neutrophil and platelet counts rapidly increased on stopping penicillin, and the bone‐marrow, which was hypocellular in some cases, became normal. Further studies on one of these patients, using a fluorescent antiglobulin technique with paraformaldehyde‐fixed cells, demonstrated a complement‐fixing IgG penicillin antibody reacting with the patients granulocytes and platelets in the presence of the drug. This suggested an immune mechanism similar to the well‐recognized penicillin‐induced immune haemolytic anaemia. The associated bone‐marrow hypoplasia may also be due to antibody‐mediated suppression of penicillin‐coated precursor cells.

Detection of Chromosome Abnormalities Pre–High-Dose Treatment in Patients Developing Therapy-Related Myelodysplasia and Secondary Acute Myelogenous Leukemia After Treatment for Non-Hodgkin’s Lymphoma

PURPOSE To assess whether pre-high-dose therapy (HDT)-related factors play a critical role in the development of therapy-related myelodysplasia (tMDS) or secondary acute myelogenous leukemia (sAML). PATIENTS AND METHODS Twenty-nine of 230 patients with a primary diagnosis of non-Hodgkins lymphoma (NHL) developed tMDS/sAML after HDT comprising cyclophosphamide and total-body irradiation (TBI) supported by autologous hematopoietic progenitor cells. G-banding and fluorescence in-situ hybridization (FISH) were used to detect clonal cytogenetic abnormalities. RESULTS The majority of patients showed complex karyotypes at diagnosis of tMDS/sAML containing, in particular, complete or partial loss of chromosomes 5 and/or 7. Using single locus-specific FISH probes, significant levels of clonally abnormal cells were found before HDT in 20 of 20 tMDS/sAML patients screened, compared with three of 24 patients screened who currently have not developed tMDS/sAML, at a median follow-up of 5.9 years after HDT. CONCLUSION Prior cytotoxic therapy may play an important etiologic role and may predispose to the development of tMDS/sAML. Using a triple FISH assay designed to detect loss of chromosomal material from 5q31, 7q22, or 13q14, significant levels of abnormal cells can be detected before HDT and may predict which patients are at increased risk of developing secondary disease. Further prospective evaluation of this FISH assay is warranted to determine its predictive power in this setting.