Oral combination chemotherapy in conjunction with filgrastim (G-CSF) in the treatment of AIDS-related non-Hodgkin's lymphoma: evaluation of the role of G-CSF; quality-of-life analysis and long-term follow-up.

In 1993 we reported the efficacy and toxicity profile of an oral combination regimen administered to 18 patients with AIDS-related lymphoma (NHL-1 study). We observed a 61% response rate; 39% one-year survival rate; nearly two-thirds of patients developed > or = grade 3 leukopenia; and 28% of cycles were associated with febrile neutropenia. These results prompted us to shorten the duration of therapy and to add G-CSF to ameliorate the myelosuppression. Twenty patients with biopsy-proven AIDS-related lymphoma were treated with three 6-week cycles of oral chemotherapy consisting of lomustine (CCNU) 100 mg/m2 on day 1, cycles no. 1 and 3; etoposide 200 mg/m2 days 1-3; cyclophosphamide and procarbazine both 100 mg/m2 days 22-31; and G-CSF 5 microg/kg subcutaneously days 5-21 and days 33-42 (NHL-2 study). The following analyses were undertaken: (1) evaluation of toxicity and efficacy parameters for patients in the current (NHL-2) study; (2) analysis of the clinical role of G-CSF by (historical) comparison with the NHL-1 study of the same regimen without G-CSF; (3) quality-of-life assessments using the Functional Living Index-Cancer (FLIC) and Brief Symptom Inventory (BSI) instruments for all 38 patients (NHL-1+2); and (4) long-term follow-up for all 38 patients. In the current study the overall objective response using ECOG criteria was 70% (95% CI, 50-90%) with 6 CRs (30%) and 8 PRs (40%). The median survival duration was 7.3 months (range: 0.5-51+ months). One patient developed CNS relapse. There were no significant differences with respect to demographics or prognostic factors between the patient populations of the NHL-1 study and the current study (P > 0.2 for each factor). Myelosuppression was the major toxicity in both studies. In the current study versus the NHL-1 study, although the lower incidences of grade 3/4 myelosuppression (51% vs. 64%) and febrile neutropenia (17% vs. 28%) on a per cycle basis were not statistically significant, fewer patients (40% vs. 60%) were affected. However, the severity of myelotoxicity was lessened with the addition of G-CSF, measured in terms of the discontinuation of therapy, myelotoxic deaths, and freedom from grade 3/4 myelotoxicity ( P < 0.02). The number of hospitalizations for febrile neutropenia (7 in the NHL-2 study vs. 13 in the NHL-1 study) was also significantly different (P < 0.05). Quality-of-life analysis confirmed no significant functional or psychological deterioration during therapy except for patients experiencing febrile neutropenia, whose functional capacity deteriorated (P < 0.04). The 1-year, 18-month, and 2-year survival rates for the combined studies (38 patients) were 32%, 21%, and 13%, respectively. At time of death 49% of patients were free from progression of their lymphoma. Administration of the oral regimen has resulted in 13% of patients surviving two years, and half of patients surviving free from progression of their lymphoma. This regimen is efficacious and considerate of patient quality-of-life issues. The addition of G-CSF to the regimen decreases the frequency of hospitalization for febrile neutropenia.

Molecular cloning and characterization of human eosinophil Charcot-Leyden crystal protein (lysophospholipase). Similarities to IgE binding proteins and the S-type animal lectin superfamily.

We have isolated and sequenced a 598-bp full length cDNA clone for the human Charcot-Leyden crystal (CLC) protein (eosinophil lysophospholipase), the unique and prominent constituent of human eosinophils and basophils that forms the hexagonal bipyramidal crystals classically observed in tissues and secretions from sites of eosinophil-associated inflammation. A 426-bp open reading frame encoded a 142-amino acid polypeptide with a predicted molecular mass of 16.5 kDa and isoelectric point of 7.28. The deduced amino acid sequence of CLC protein showed 20 to 30% similarity over regions of approximately 100 amino acids with the carboxyl-terminal domains of four IgE-binding proteins, including the 31-kDa human and rat IgE-binding proteins, the 35-kDa mouse carbohydrate binding protein (CBP35), Mac-2, the murine macrophage cell surface protein that is identical to CBP35, and the human homologue of Mac-2. These proteins are members of a superfamily of beta-galactoside binding S-type animal lectins, which includes a group of highly conserved 14-kDa lectins isolated from human lung, heart, placenta, bovine heart, chicken skin, mouse fibroblasts, and the electric organ of the electric eel; CLC protein also showed sequence similarities to these 14-kDa animal lectins, including conservation of 7 of 16 invariant amino acid residues thought to comprise the carbohydrate-binding domain of these proteins, with conservative amino acid changes at others; thus, CLC protein could potentially possess carbohydrate or IgE-binding activities. Northern analyses revealed an approximately 900-bp mRNA species that was present in peripheral blood eosinophils from patients with eosinophilia, basophils from patients with chronic myelogenous leukemia, and in HL-60 cells induced towards eosinophilic differentiation with B cell growth factor-II (IL-5) or granulocytic differentiation with DMSO, but was absent in neutrophils, monocytes, T cells, B cells, or HL-60 cells induced towards monocytic differentiation with vitamin D3. Southern analyses revealed a gene of approximately 5 to 6 kb in length. The cDNA clone and complete amino acid sequence data for CLC protein will facilitate structure-function analyses of its unusual hydrophobic properties, unique propensity for crystallization, lysophospholipase, and potential lectin-like activities.

Acute myelogenous leukemia: current treatment and future directions.

Acute myelogenous leukemia (AML), although an uncommon disorder, is a useful prototype for the treatment of malignancies in general. Significant advances have been made in both the understanding and treatment of this disease. In particular, clinically relevant molecular mechanisms of disease in AML are being defined that hold future therapeutic promise. We review the classification and biology of AML and the current treatment controversies in the use of chemotherapy and bone marrow transplantation, and suggest directions for future research.