Introduction
Modern chemotherapy has increased the survival of childhood acute lymphoblastic leukemia (ALL) upto 90%;1–4 but it comes with the consequences of immune defence abnormalities and increased susceptibility to infections.5 Infection is an important cause of morbidity and mortality in children with ALL during chemotherapy, especially in developing countries.6 Reduction of intensity of chemotherapy for ALL had resulted in a major reduction in infectious morbidity,7 explaining the possibility that serum immunoglobulin levels and specific antibody levels may be less affected in children treated with reduced dose chemotherapy.8Few studies have focussed on the effect of chemotherapy on serum immunoglobulin levels, and its effect on infective complications.9–12 Many studies on infection and immunosuppression in ALL are without stratification for the period and intensity of chemotherapy. Maintenance chemotherapy bears the accumulation of previous intensive chemotherapy and reduced reserve for hematopoesis and is of the longest duration of continuation treatment. Children are less intensively monitored during this period of chemotherapy due to reduced intensity of chemotherapy and less frequent use of parenteral chemotherapeutic agents. Continuation of maintenance chemotherapy as outpatient treatment also poses significant risk of exposure to infections via community contacts. There is scarcity of data correlating immunosuppression especially hypoglobulinaemia with occurrence of infections during maintenance chemotherapy. Most of such studies in paediatric ALL are from developed countries, where infections and related mortality are less. Role of intravenous immunoglobulin (IVIG) in reducing infectious complications and improving outcome of infections is still unclear, so is the timing of IVIG for prophylaxis or treatment.9,13 This study aimed to monitor ALL children for severe infections during maintenance chemotherapy in the Indian setting and to find out the risk of severe infections with hypoglobulinaemia.