Etoposide and mitoxantrone in newly diagnosed acute myeloid leukemia patients with persistent leukemia after a course of induction therapy with cytarabine and idarubicin

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Background: The goal of induction chemotherapy in acute myeloid leukemia (AML) is complete remission with restoration of normal bone marrow. If residual leukemia is present after the first course of induction therapy, patients receive a second course identical to the first or receive a non-cross resistant antileukemic regimen. Methods: In a retrospective study of adult patients with newly-diagnosed AML treated at the University of Pittsburgh Cancer Institute between December 2002 and May 2008, we evaluated the efficacy and toxicity of mitoxantrone (10 mg/m2/d) and etoposide (100 mg/m2/d), both administered intravenously within 5 days as second course therapy of patients not responding to first-course induction therapy with cytarabine and idarubicin. Univariate and multivariate associations between patient characteristics and complete response (CR) were assessed by logistic regression, with overall- and relapse-free survival estimated by Kaplan-Meier analysis. Results: 74 AML patients (mean age 56 years, range: 18–73 years) completed treatment with etoposide and mitoxantrone; 29 (39%) achieved CR. Lower CR rate was associated with unfavorable cytogenetic risk status at diagnosis and higher percent blasts prior to treatment with mitoxantrone and etoposide. Ten (14%) patients died due to infectious complications. No grade 3 or 4 hepatic toxicities were observed. One patient developed grade 3 cardiac toxicity. Median duration of neutrophil recovery following therapy in patients achieving CR was 29 days. Median overall survival was 9.0 months (95% CI 5.8–14.9 months). The 29 patients who achieved CR received postremission therapy: 16 of these eventually relapsed, while 4 others died without evidence of relapse. Median duration of relapse-free survival in these 29 patients was 11.0 months (95% CI: 9.0–19.3 months). Conclusions: Our study suggests that the combination of etoposide and mitoxantorne is an active and well-tolerated regimen as second-course therapy in newly diagnosed AML patients who have persistent leukemia after a first course of induction therapy with cytarabine and idarubicin.

No significant financial relationships to disclose.

Subtypes of intercalated cells in rat kidney collecting duct defined by antibodies against erythroid band 3 and renal vacuolar H+-ATPase

The cellular distributions of the kidney form of the erythrocyte band 3 chloride/bicarbonate exchanger and the kidney vacuolar H+-transporting ATPase were examined in rat kidney collecting duct by immunocytochemical staining of adjacent semithin sections. Polyclonal anti-peptide antibodies directed against two regions of murine erythroid band 3 gave a pattern of basolateral labeling similar to that seen with antibodies directed against the entire protein. In the medullary collecting duct almost all intercalated cells expressed basolateral membrane band 3 and displayed apical membrane H+-ATPase. In the cortical collecting duct and the connecting segment, band 3 labeling was restricted to a subpopulation of intercalcated cells. In the cortical collecting duct 46% of intercalated cells had apical H+-ATPase and basolateral band 3. Cells that had either basolateral or diffuse cytoplasmic staining for H+-ATPase were all band 3-negative and accounted for 53% of the intercalated cells. In addition, occasional intercalated cells with apical H+-ATPase appeared to lack basolateral band 3. These results demonstrate the coexpression of H+-ATPase and band 3 in opposite plasma membrane domains of a subpopulation of intercalated cells that are probably the acid-excreting (type A) cells. All other intercalated cells lacked immunoreactive band 3 and probably include the bicarbonate-excreting (type B) cells.

Polymerase activity in lymphocyte culture supernatants from patients with Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis of infancy and early childhood characterized by high fever, rash, mucositis, lymphadenopathy and coronary artery damage. Large epidemics have been described in Japan and the United States and the number of cases reported annually is steadily increasing. The aetiology of KD is unknown. During the acute phase of the disease marked immunologic alterations occur including generalized T-cell lymphocytopenia, activation of circulating T4+ helper T cells, decreased numbers of T8+ suppressor T cells and marked B-cell activation. We postulated that a lymphotropic virus with affinity for endothelial and lymphoid cells might explain the vasculitis and immunological abnormalities in KD. We report here our study of the particulate fraction from culture supernatants of peripheral blood mononuclear cells (PBMC) for evidence of retrovirus-associated reverse transcriptase (RT) activity. Activity was found in the supernatants from KD patients but not control cultures. This RT activity was transmitted to an established T-cell line (HUT-78) and thus may be due to an exogenous agent infecting KD lymphocytes.