Search

Noise in the immunohematological investigations can be described as a false reactivity of red blood cells (RBCs) in serologic testing that is not related to the interaction of RBC antigens and antibodies that the test system is intended to detect. These false-positive reactions can cause confusion during the cross-matching and RBC antibody screening and may result in delays in patient transfusion. Although these antibodies are predominantly clinically insignificant, proper laboratory work-up is indicated to avoid misidentification of a clinically significant antibody as a noise. In this report, we describe the three rare cases where the reactivity was found against the ingredients of the column matrix (glass beads). It is imperative that such reactivity is recognized and resolved during the investigation of blood group discrepancies, positive RBC antibody screens and in cases of positive cross-matches. [ABSTRACT FROM AUTHOR]

A 52-year-old male repeats voluntary blood donor donated at our blood center for the first time. Historical blood group was O, Rh (D) positive. Initial blood grouping was done on the fully automated immunohematology analyzer using column agglutination technique (CAT). Discrepant results (forward as group O and reverse as group B) were observed while performing the ABO blood grouping by CAT. Repeat testing by conventional tube technique showed the same discrepancy. Antibody detection test and direct antiglobulin test results were negative. After adsorption-elution, the eluate reacted only with group B red cells. Saliva testing for secretor status shows the presence of B and H substances. Finally, it was classified as a case of Bm (now called Bweak) phenotype. As a precautionary measure, the donor was recalled and a special blood group card was issued with a clear mention of his respective donor and recipient status. This case showed the importance of ABO subgroup determination that can help blood centers to establish defined transfusion protocol and prepare an elaborate rare blood donor registry. [ABSTRACT FROM AUTHOR]

Conclusions: Anti-M is a frequently detected naturally occurring antibody that has been reported in various clinical settings and also in voluntary donors. We describe here the clinical and laboratory findings of 11 cases with anti-M detected at our center. This report is a retrospective study in which we reviewed our immunohematology laboratory records for cases involving anti-M. Both donor and patient data from a 28-month period (September 2014 to December 2016) were reviewed. During this period, 11 examples of anti-M were detected (8 patients, 1 voluntary whole blood donor, and 1 hematopoietic stem cell donor. Anti-M was also detected in one external quality assessment scheme sample received during this period. In conclusion, anti-M can be detected in various clinical settings. This antibody can be clinically significant; in the laboratory, it can present as a serologic problem such as an ABO group discrepancy or an incompatible crossmatch. After detection, management and course of action is determined by both the antibody characteristics and the clinical setting.