Prevalence of Serologic Weak D Phenotype in Iranian Blood Donors: A Nationwide Retrospective Cross‐Sectional Study
Younes Sadeghi‐Bojd, Narges Sadat Razavi Alhosayni, Fatemeh Mirzaeyan, Fatemeh Mohammadali, Arezoo OodiABSTRACT
Background and Aim
The serologic prevalence of the Weak D phenotype varies across populations and may be influenced by laboratory methodology. However, nationwide data from Iran remain limited. This study aimed to determine the nationwide serologic prevalence of the Weak D phenotype among Iranian blood donors and to compare detection rates between manual and automated RhD typing methods.
Methods
This nationwide retrospective cross‐sectional study included 1,991,758 blood donors from all 31 provinces of Iran between December 2022 and December 2023. RhD typing was performed using either manual tube testing or automated platforms (Magnet and solid‐phase red cell adherence [SPRCA]). Prevalence estimates with 95% confidence intervals (CIs) were calculated and compared using χ 2 and paired analyses.
Results
Among 1,991,758 blood donors, 213,693 (10.72%) were Rh‐negative. Serologic Weak D was identified in 1001 donors, corresponding to an overall prevalence of 0.0503% (95% CI: 0.0472–0.0535) and 0.4684% among Rh‐negative donors. The prevalence was 0.0491% with manual testing and 0.0518% with automated testing, with no significant difference between the two methods ( χ 2 = 0.681, p = 0.41). Within the automated group, SPRCA demonstrated a significantly higher detection rate than the Magnet platform (0.0619% [95% CI: 0.0545–0.0707] vs. 0.0445% [95% CI: 0.0390–0.0507]; χ 2 = 12.227, p < 0.001). In provinces where both methods were used concurrently, paired analysis showed a significantly higher mean detection rate with automated testing ( p = 0.023).
Conclusion
The nationwide prevalence of serologically detected Weak D phenotype in Iranian blood donors was 0.0503%, placing Iran within the lower range of global estimates. Although no significant overall difference was observed between manual and automated RhD typing, the Solid Phase platform demonstrated significantly higher detection rates than the Magnet platform. These findings support standardized RhD typing strategies to improve diagnostic consistency and optimize transfusion safety at the national level.