Allogeneic Hematopoietic Cell Transplantation for Acute Lymphoblastic Leukemia in Adults

Higher rate of central nervous system involvement by flow cytometry than morphology in acute lymphoblastic leukemia

INTRODUCTION

Central nervous system (CNS) involvement in acute lymphoblastic leukemia (ALL) is diagnosed traditionally by cytopathology (CP) of the cerebrospinal fluid (CSF). Role of flow cytometry (FC) to diagnose CNS involvement has not been extensively investigated.

METHODS

We aimed to detect CNS involvement in 42 ALL patients (33 B-ALL, nine T-ALL) at diagnosis by FC and comparing it with CP and to correlate it with known risk factors for CNS disease like Lactate dehydrogenase (LDH). A receiver operating characteristic curve was used to determine the cutoff of LDH to predict CSF involvement. For the analysis of categorical/quantitative variables, Fisher's exact test was used. For the analysis of continuous variables, Mann-Whitney test was used. A P value of <.05 was taken as significant.

RESULTS

CP and FC were positive in five (11.9%) and 11 patients (26.14%) respectively with FC detecting a significantly higher level of involvement (P=.001). All CP-positive cases were FC positive. A LDH value of >472 U/L had a sensitivity of 61% and specificity of 62.5% for diagnosis of CSF involvement by FC.

CONCLUSIONS

CSF FC detects CNS disease in ALL patients at diagnosis at a rate double than CP alone and is statistically associated with an elevated LDH level. It should be incorporated in the evaluation of CSF to detect CNS involvement.

Allogeneic transplantation for lymphoma

Historically, high levels of treatment-related mortality restricted the use of standard myeloablative allogeneic stem-cell transplantation to a minority of young and fit patients with lymphoma. Over the last decade, increasing numbers of patients with lymphoma have undergone allogeneic stem-cell transplantation using reduced-intensity protocols that are associated with lower toxicity and reduced transplantation-related mortality. Graft-versus-lymphoma effects contribute to the therapeutic effect in patients with indolent or Hodgkin's lymphoma. However, definitive evidence for efficacy of this strategy is lacking because most patients undergoing transplantation do so after failure of several lines of treatment, leaving no obvious comparator arm for randomized controlled studies. Nevertheless, encouraging results have been reported for selected patients for most lymphoma subtypes, with pretransplantation disease status emerging as the most important predictor of outcome. The major long-term toxicity is chronic graft-versus-host disease that contributes to ill health in a significant minority of survivors. In the future, risk-adapted trials that evaluate reduced-intensity allogeneic transplantation in patients with predicted poor outcomes with immunochemotherapy or autologous transplantation will be important in determining the role of this treatment.