Antibody screening in the general population: A single center experience in Karachi.

Abstract

Objective: To evaluate the prevalence and spectrum of red cell antibodies in the general population of Karachi. Study Design: Cross-sectional Descriptive study. Setting: Department of Blood Bank Chughtai Lab, Karachi. Methods: April 2024 to April 2025. Methods: A total of 999 samples were recruited for antibody screening. Individuals of all age groups and both genders were included. From each participant, approximately 7 mL of venous blood was drawn using a vacutainer and collected into two separate tubes. Descriptive statistics were used to summarize the findings (using SPSS v24.0). Results: 999 samples were screened for red cell antibodies, of which 77 (7.7%) tested positive. The majority of positive cases were females (93.5%), with a median age of 28.5 years compared to 26 years in males. Anti-D was the most common alloantibody (32.5%), followed by weak positive reactions (16.9%), auto antibody-positive cases (14.3%), and combinations such as anti-D with anti-C (9.1%) and anti-E (9.1%). Less frequent antibodies included anti-c, anti-K, anti-M, anti-C, anti-Jka, and anti-Fya. A significant association was observed between gender and the type of antibody detected (p = 0.016). Conclusion: The prevalence of red cell alloantibodies in the subset population of Karachi was 7.7 %, with a marked predominance among females. Anti-D emerged as the most common antibody, followed by other Rh and non-Rh specificities.