[Introduction of a new index to compare function of screening labs of thalassemia prevention program in Isfahan province]

Although major beta-thalassemia prevention and control program is one of the most successful programs in genetics field, there are new cases of major beta-thalassemia due to laboratory errors. So the laboratory quality control [QC] is very important to diagnose carriers in preventive programs. At present, there is not a distinct and measurable index for function assessment and comparison in screening laboratories; this urged us to create an objective, measurable and explicit index for health care givers. For this purpose, we compared the function of screening labs in districts of Isfahan Province. In this cross-sectional study, we collected the data from "pre-marriage screening program" in 18 districts [19 screening labs] covered by Isfahan University of Medical Sciences from 2006 to 2008. The percentage rates of "screened males with low blood indexes" in every 3 months [P index] were assessed; then, the average and coefficient variants in duration of 3 years were calculated with excel software. Based on these findings, "screening labs' functions" were assessed and compared. The least "CVs of P index" within 19 labs were found to be in Mobarakeh laboratory [10.4%] and Provincial reference lab [10.9%], respectively. The highest CVs were found in Khour [76.3%] and Tiran and Karvan labs [58.2%], respectively. The P index average in all centers was 14% [13.9% in reference lab] with the highest being in Mobarakeh[24.2%] and the lowest in Khour[8.8%]. Whereas the number of marriage candidates in each screening lab is relatively stable, the centers with the highest CV value of P index are probably lower in function level as compared with the centers with the lowest CV value of P index [as in reference screening lab]. CV of P index may be a good evidence for quality of "screening lab function" and should be evaluated annually. The screening labs with high CV of P index need more attention and evaluation

Alloantibody detection in major beta thalassemic patients transfused within less-than-20-day intervals

Mismatched red blood cell phenotypes between donors and recipients in multiple blood transfusions can result in the development of alloimmunization in recipients. We studied in this research the effect of alloantibodies on the increase of need of blood transfusion in major thalassemiacs. This is a descriptive study in which 2 groups of major thalassemiacs with more and less than 20 days of blood transfusion intervals [27 patients vs. 25] were evaluated for the presence and frequency of alloantibodies and related factors. We used t-test and t-student tables for evaluating the results. 55% of patients in the first group had developed alloantibodies and their annual transfused blood volume was more than those who were not immunized [p<0.005]. Male gender and initial blood transfusion in children under 3 years old were related to the absence of alloantibodies. 100% of patients in the second group were immunized, and those who received higher amounts of blood units annually [493 ml/kg and 508 ml/kg] were patients with more than two types of alloantibodies. Alloimmunization involved K [27.5%], N [12.5%], CW, s, Fy[b] [5%], C, S, E, e and M [2.5%] antigens. 100% of antibodies were of warm immunoglobulin type, and 16% both warm and cold. 17.3% of thalassemiacs were splenectomized and their need for transfused blood was less than unsplenectomized patients [p<0.005]. In most cases, annual blood transfusion in both groups was estimated to be much more than what was expected. We conclude that red blood cell matching, at least for Kell and Rh systems, is necessary to prevent alloimmunization in thalassemiacs. Hypersplenism and low quality of blood, that can increase the need for transfused blood, should be taken into consideration