ALBERT

Description: Donor lymphocyte infusion (DLI) was originally administered as a single, relatively large dose of lymphocytes called a bulk dose regimen (BDR). It has since been suggested that the use of an escalating dose regimen (EDR) may be equally effective against leukemia while it induces less graft-versus-host disease (GVHD). We therefore compared the efficacy and incidence of complications in a nonrandomized sequential study of the 2 regimens in 48 consecutive patients who had relapses with cytogenetic or hematologic evidence of chronic myeloid leukemia after allogeneic stem cell transplantation. Twenty-eight patients were treated on a BDR (August 1990 to November 1995) and 20 were treated on an EDR (December 1995 to January 1998). Although the probability of achieving cytogenetic remission within 2 years of starting DLI did not differ significantly between the 2 groups (EDR, 91% [CI, 63%–98%] vs. BDR, 67% [CI,49%–83%],P = .70), the incidence of GVHD was much lower using EDR (10% vs. 44%, P = .011). When we considered only subsets of patients treated by BDR or EDR who had received comparable total lymphoid cell doses, the incidence and severity of acute and chronic GVHD were both significantly lower for recipients treated by EDR than for recipients treated by BDR (P = .005 andP = .031, respectively). These findings suggest that the incidence of GVHD associated with the EDR is low, not because the final cell dose is small, but because lymphocytes are administered over a considerable number of months. (Blood. 2000;95:67-71)

Description: Background. The identification of the somatic mutation V617F in exon 14 of the Janus kinase 2 gene (JAK2) has simplified the diagnosis of many patients affected with typical chronic myeloproliferative diseases (MPDs). In patients without the V617F the molecular basis of MPD are still unclear but, recently, mutations in exon 12 of the JAK2 gene have been identified in a minority of patients, associated with a selective increase in erythropoiesis resulting in polycythemia vera (PV) or idiopathic erythrocytosis (IE) (Scott et al, NEJM 2007). Aim. To determine the JAK2 exon 12 mutational status in a group of JAK2 V617F negative patients with PV or IE. Methods. Genomic DNA was extracted from peripheral blood leukocytes from 85 MPD patients (PV or IE) included in the present study. All the samples were tested for JAK2 V617F mutation by allele specific polymerase chain reaction (ASO-PCR) and those negative for V617F mutant allele were subjected to real time quantitative PCR (RQ-PCR) using hybridization probes. Subsequently, all JAK2 V617F negative samples by both ASO-PCR and RQ-PCR where subjected to direct sequencing to exclude JAK2 exon 12 mutations. Results. JAK2 V617F was positive in 78 (91.7%) of the 85 patients, however, in two of these patients the V617F mutation was only detected upon subjecting genomic DNA to RQ-PCR which revealed low levels of the mutant allele, 2.65 % and 3.98%. Analysis of the JAK2 exon 12 in the seven JAK2 V617F negative patients detected three previously described mutations: a duplication (V536-1546) and two deletions (H539-K540del+542K and R541-E543 delinsK)and a previously unreported splice site mutation detected in intron 12 (IVS12nt6 T-C). To our knowledge this was the first description of intronic mutations in the JAK2 gene. No mutations were detected in the remaining 3 (3.6%) patients. Conclusions. In this cohort study JAK2 mutations were observed in 82 (96,5%), of the 85 patients, of these 78 (95.12%) had the V617F allele. In two cases V617F was detected at low levels (2.65% and 3.98%) only by RQ-PCR, highlighting the need for sensitive techniques to detect somatic mutations. One of the patients, a young male with erythrocytosis and low serum Epo levels, revealed a previously unreported splicing mutation (IVS12 nt6: T-C). This study illustrates the heterogeneity at the DNA level in PV patients which may assist in better understanding the genotype and phenotype relationship in MPD patients and assist in further delineating the role of JAK2 in these disorders.

Description: Donor lymphocyte infusion (DLI) was originally administered as a single, relatively large dose of lymphocytes called a bulk dose regimen (BDR). It has since been suggested that the use of an escalating dose regimen (EDR) may be equally effective against leukemia while it induces less graft-versus-host disease (GVHD). We therefore compared the efficacy and incidence of complications in a nonrandomized sequential study of the 2 regimens in 48 consecutive patients who had relapses with cytogenetic or hematologic evidence of chronic myeloid leukemia after allogeneic stem cell transplantation. Twenty-eight patients were treated on a BDR (August 1990 to November 1995) and 20 were treated on an EDR (December 1995 to January 1998). Although the probability of achieving cytogenetic remission within 2 years of starting DLI did not differ significantly between the 2 groups (EDR, 91% [CI, 63%–98%] vs. BDR, 67% [CI,49%–83%],P = .70), the incidence of GVHD was much lower using EDR (10% vs. 44%, P = .011). When we considered only subsets of patients treated by BDR or EDR who had received comparable total lymphoid cell doses, the incidence and severity of acute and chronic GVHD were both significantly lower for recipients treated by EDR than for recipients treated by BDR (P = .005 andP = .031, respectively). These findings suggest that the incidence of GVHD associated with the EDR is low, not because the final cell dose is small, but because lymphocytes are administered over a considerable number of months. (Blood. 2000;95:67-71)