ABSTRACT
Enormous diversities of heavy chain immunoglobulin [IgH] and IgK molecules are generated during B- and T-lymphocyte differentiation through the rearrangement of gene segments. Additionally, random insertion and deletion of nucleotides between gene segments make unique sequences which are cell or clone specific. IgH and IgK gene rearrangements are the most and relatively common reported rearrangements in B-precursor acute lymphoblastic leukemia, respectively. The purpose of this study is to evaluate the pattern of IgH and IgK gene rearrangements using polymerase chain reaction [PCR] in BP-ALL in Iranian children. For this prospective study, bone marrow aspirates of 183 patients with the diagnosis of acute leukemia were collected at admission before any chemotherapy. Having reviewed cytomorphology [L[1]:44%, L[2]:41%] and immunophenotyping, only 140 cases with the diagnosis of B-precursor ALL were selected. Mononuclear cells including leukemic blasts were isolated by density gradient. Having DNA extracted, hyper-variable regions of IgH and IgK were amplified by consensus primers using PCR. PCR products were analyzed after heteroduplex analysis and polyacrylamide gel electrophoresis [silver stain]. The DNA sequences were compared and aligned to the sequences homologous for IgH and IgK published by Gene Bank. IgH gene rearrangements were found in 114 [90.4%] of patients using consensus primers for CDR-III and CDR-I regions [monoclonal 57.8% biclonal 34.9% oligoclonal 5.5%]. Four of nine patients with T-ALL had clonal rearrangements of IgH. Clonal pattern of Ig?-Kde were present in 59 [67%] of cases [biclonal 10%]. VKI [25%] and VK? [22.7%] were the most common type of rearrangements. Clonal rearrangement pattern of IgH gene was similar to other populations. Using FRI and FRIII primers in multiplex PCR increased the rate of detection and reducing turnaround time. IgK was slightly more frequent than previous reports while VKI [25%] was the most common type
ABSTRACT
Langerhans cell Histiocytosis [LCH] is a rare disease characterized by clonal prolifera-tion of Histiocytosis in different tissues. Permanent consequences [PC] described among subjects with Langerhans cell histiocytosis [LCH]. In this study we report the prevalence of permanent sequel among long - term survivors of LCH in our center. We had 30 cases of LCH from 1989 - 2001 who came for at least 3 years after diagnosis. In-formation has been collected from their disease history, and on type and date of onset of any PC. The cumulative risks of developing a PC have been calculated from the date of LCH diagnosis using the Kaplan-Meier and non-parametric method. Among 30 patients 53.3% were female, 46.67% male, mean age at diagnosis 56.86%'7.79 months [range 7-156], median 42.5 months. 19 [63.33%] had single system [SS] and 11 [36.66%] mul-tisystem [MS]. Mean age at SS 5.97 +/- 1.03 yr, mean age of MS 7.59 +/- 1.05 yr. Mean age at follow up 11.3 +/- 0.9 yr, median 11.5 yr, range 4.16-22 yr. Mean duration of follow up 6.57 +/- 0.76 yr, median 5 yr, and range 3-18 yr. Nine of 30 cases [30%] had at least 1PC; in SS [26.3%] and in MS [36.7%]. The most frequent PC was diabetes insipidus [DI] 16.7%, in SS 5.26%, in MS 36.36%, the difference is significant P < 0.05.Orthopedic abnormalities 10% which was only in SS [15.79%], growth retardation [GR] 13.34%. The prevalence of PC in our patients is low which could be due to a small sample and on the other hand as most of our patients had single system involvement, the exact prevalence of PC is not clear. Analysis of cumulative risk shows that some types of PC may become manifest many years from diagnosis and long term follow up is necessary for all patients