Middle-East Journal of Scientific Research 2 (2): 57-62, 2007 ISSN 1990-9233 © IDOSI Publications, 2007 Corresponding Author: Dr. Sudha Sazawal, Department of Haematology, IRCH Building (I Floor), AIIMS, New Delhi - 110029, st India 57 Immunoglobulin (Ig) and T-Cell Receptor (TCR) Gene Rearrangement Pattern in Adult Acute Lymphoblastic Leukemia in India Sudha Sazawal, Kishor Bhatia, Vinod Raina, 1 1 2 Renu Saxena, Anshu Khattar and Manorama Bhargava 1 1 3 Departments of Haematology, Medical Oncology, 1 2 All India Institute of Medical Sciences, New Delhi, India Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi, India 3 Abstract: ALL in adults is an entity distinct from that in children, as the two have different prognostic factors. Amongst factors affecting prognosis in adult ALL, literature on molecular rearrangement is limited, we therefore analysed the Ig and TCR gene rearrangements in adult ALL and looked for their correlation with the disease outcome. In 52 cases of ALL (median age 23 years), IgH chain gene was rearranged in 97% B-Cell Precursor (BCP) ALLs and 40% T-ALLs. One or the other TCR locus was rearranged not only in all T-ALLs, but also in 86% of BCP-ALLs. Though the overall survival in patients with TCR rearrangement was least, both in BCP- ALL (34.3 ± 19.5% vs. 72.2 ± 11.9%, p=0.16) and T-ALL (25.0 ± 21.7% vs. 75.0 ± 21.7%, p=0.23), but it was not statistically significant. Moreover, in BCP-ALL, IgH locus with more than 2 bands rearranged was associated with a lower Hb at presentation (mean 4.8 Vs 7.4 g/dL, p=0.01). The pattern of rearrangement of these genes in our study appeared to be different from the West, viz TCR- rearrangement was seen in a higher proportion f BCP-ALLs (68%) and rearrangement for TCR- genes were invariable deletions of C 1 and TCR- locus had only monoallelic rearrangement. Key words: Adult ALL ALL in India immunophenotype Ig gene rearrangements TCR gene rearrangements NTRODUCTION MATERIALS AND METHODS Acute lymphoblastic leukemia in adults has a worse Patients: Fifty two cases of adult ALL (age >16 years) prognosis than that in children [1, 2]. Some factors presenting to the Medical Oncology Clinic of All India responsible for this difference include advanced age, Institute of Medical Sciences, New Delhi, India, from 1991 hyperleukocytosis at presentation, higher frequency of to 1999 were included in the present study. Of these 37 more immature B or T lineage phenotypes, lack of TEL were classified to have B-lineage and 15 T-lineage gene rearrangements, higher proportion of patients with origins. The median age of the patients was 23 years the t(9;22) Ph+ translocation [1, 3]. The analysis of Ig and (range 16-55 years), 42 of them were males and 10 were TCR genes is a tool to characterize the disease and females. The median WBC count was 55x10 l (range detect clonal assessment at the molecular level [4]. 5.7x10 - 440x10 l ). Patients were treated with MCP-841 Unlike childhood ALL, limited studies on the biology of protocol [11]. Briefly, the protcol uses three induction this disease in adults are available [5-7]. Although very cycles of 28 days each (prednisolone, vincristine, few studies have reported the rearrangement pattern L-asparaginase, daunorubicin, 6-mercaptopurine, in adult ALL [8-10], the clinical significance of these cyclophosphamide), followed by consolidation of rearrangements is limited. In the present study, we remission (cyclophosphamide, vincristine, 6- attempted to elucidate the clinical significance of the mercaptopurine, cytosine arabinoside and prednisolone). above rearrangements in adult ALL. Subsequently, 6 maintenance cycles of 3 months each 9 1 9 9 1