Need To Register Consanguinity To Avoid Transfusions in Random Fashion among Close Relatives.

Transfusion associated graft versus host disease (TGVHD) is a complication of transfusion (T) among close relatives but this event is not usually registered. In a search in Medline, since 1966 to present, no references where found on the need to register consanguinity between donors and receptors. The object of this research was to determine the importance of recording consanguinity (C) transfusions in a random fashion to avoid TGVHD. Between January 2001 and June 2003 the presence of C between blood donors and patients (P) on the Donor’s Book and in the mother and satellite blood bags for platelets were registered. Donations (D) were directed (DD) or non-directed (ND). 10,827 D were registered, from which 18,406 units (U) of cellular hemocomponents (CH) apt for transfusion were obtained. Of these, 1,868 D (17.3%) were C with the P and 3,324 (18%) U of CH apt for transfusion were obtained. In order to investigate the chance of a random transfusion of CH to C we excluded from the probability analysis the following U: 1) ABO/Rh incompatible: 157 (4,7%). 2) Already transfused or discarded at the moment of the transfusion order: 304 (9,1%). 3) Not donated at the time of the transfusion order: 504 (15,2%). 4) Irradiated hemocomponents (for C, DD, inmunodeficiencies, etc.): 624 (18,8%). 5) Non-transfused because of absence of transfusion order for the C patient: 846 (25,5%). U from C donors ready for transfusion to a C patient was 889 from 3.324 (26,7%). According to the Accountant Book, at the moment of transfusion the pondered S from C donors was 1.067 U. In the same way, at the moment of transfusion for C receptors, the pondered S of all balance of CH not belonging to C donors was: 28,720 U. In this study the chance that a patient receives at least one U of CH from C donors in a random fashion was [1.067 /28.720 + 1.067] x 100 = 3,6 %. Although the incidence of TGVHD is unknown it is thought to be very low. The chance of 3.6% of receiving at least one U of CH from a C donor in a random way is high and justifies largely considering this event to be registered. This percentage could suffer significant variations for different modalities of Blood Banks with regards to donation, storage and supplying of CH.