Background: Most people are either RhD positive or RhD negative, but there is also a number of persons with D antigen variants. The aim of this study was to prove, by using molecular diagnostic tests, whether the RHD gene and D antigen on the red cell membrane of the blood donors serologically typed as RhD-negative with RhD phenotype Ccddee and ccddEe, are so weak that they cannot be proven by serology techniques or the available anti-D test serums. Methods: Samples used are those of regular voluntary donors who were serotyped as RhD-negative, C and/or E positive. Samples were collected from voluntary donors at the Institute for Transfusion Medicine of the Republic of Srpska during the period from April 2016 to December 2018. Results: Among the serologically proven RhD-negative donors, 346 had C and/or E in their phenotype and those were subjected to molecular screening test. Conclusion: The first results of molecular typing match those published in literature, i.e. the RHD gene is present in some serologically RhD-negative forms, which was proven by molecular testing.

Introduction: The Rh system is very complex, polymorphous and the most significant for clinical practice, along with the ABO blood group system. The D antigen is the most important antigen in the Rh system and the most immunogenic one, following the ABO antigens. The D antigen, which consists of a mosaic of epitopes, is determined in all the blood donors and patients. Most people are either RhD positive or RhD negative, but there is a certain number of people who have a variation of the D antigen, which are called weak D, partial D and DEL phenotypes. Aim of the Study: The objective is to use molecular methods to determine whether blood donors in the Republic of Srpska (with whom a serological weak D antigen has been detected) really have the weak D antigen, partial D, a combination of these two variants or if their D antigen is normally present, but the used anti-D serum tests did not have the avidity needed to prove the presence of this antigen in blood donors. Patients and Methods: Blood samples were used from regular blood donors, who had been determined as persons with a weaker D antigen (based on the agglutination strength) using serological techniques, the test tube method, the microplate method and the gel method. To determine the blood groups and red blood cell/erythrocyte antigen typing, the following methods were applied: a) test tube method or agglutination in an aqueous environment, b) gel method, c) microplate method and d) molecular determination of blood groups. Results: Blood group samples were collected from April 2016 to February 2017 in the Institute for Transfusion Medicine of Republika Srpska. During this period, blood was collected from 8153 voluntary donors. It was serologically proved that 40 donors (0.49%) had the weak D antigen. All results where the weak D antigen was determined serologically were confirmed by molecular testing. 23 respondents were proved to have weak D type 3 (0.28%), while 17 had weak D type 1 (0.20%). Conclusion: The results from the first molecular testing of our population is in accordance with the results of frequency of weak D antigen in the populations of other European countries, though it did show a small advantage of weak D type 3 over weak D type 1.

Introduction: Identifying voluntary blood donors with rare phenotype characteristics is the basic precondition for creating a registry of blood donors with rare blood groups. Aims of the study: Determining the presence of phenotypes in the clinically most relevant blood group systems in regular blood donors at the Institute for Transfusion Medicine of the Republic of Srpska, with the goal to create a national registry of blood donors with rare blood groups. Patients and Methods: Determination of antigens in the Rh system was performed by the automatic microplate method, as well as by gel method. Determination of antigens in other blood group systems Kell, Kidd, Duffy, MNS, Lewis and Lutheran was performed by the gel method and test tube method. Altogether 384 blood donors were screened between 2012 and 2013. Results: The analysis of Rh phenotypes showed that most of the examinees had the Rh phenotype CcDee ,29.7% and 26.0% the ccddee, and the least of them had the Rh phenotype ccddEe 0.8%, Ccddee 1.6% and ccDee 2.3%. The antigen Cw was proved to be in 13 donors (3.4%), while the antigen P1 was detected in 291 donors (75.8%). In analyzing the Lewis antigen system, most of the blood donors were found to have the phenotype Le (a-b+), 74.0%. By analyzing the Lutheran antigen system, the phenotype Lu (a-b+) was detected in most of the donors typed for Lutherean antigens, that is, in 93.0% of them. One individual was found to have the phenotype Lu (a+b-) (0.3%), and two donors the phenotype Lu (a-b-) (0.5%). The analysis of the Kell antigen system showed most of the donors were of the phenotype kk, 93.2%, one individual was found to have the phenotype KK (0.3%) and 25 donors the phenotype Kk (6.5%). In analyzing the Kidd antigen system, most of the donors were found to have the phenotype Jk(a+b+), 46.6% and 29.4% the Jk(a-b+), whereas 24.0% had the phenotype Jk(a+b-). According to the study of MN antigen in the MNS system, most of the donors were typed as MN, 50.0% and 33.9% as MM, while the phenotype NN was detected in 16.1% donors. Analyzing the S and s antigens in the MNS system, the phenotypes Ss were found in most of the donors, 49.0% and ss in 43.2%, whereas the phenotype SS was detected in 7.8% donors. The analysis of the Duffy antigen system showed most of the donors were of the phenotype Fy(a+b+), 46.6% and 34.6% of the Fy(a-b+), while the phenotype Fy(a+b-) was observed in 18.8% donors. Conclusion: Data on the distribution of clinically relevant erythrocyte antigens among regular blood donors in the Republic of Srpska is in accordance with the data set out in the literature for the caucasian.

No abstract