Abstract

Duffy Red Cell Phenotypes among Pregnant Women in Sokoto, North Western Nigeria

O Erhabor, CE Shehu, YB Alhaji and A Yakubu

Background: Duffy blood group system is one of the clinically significant blood group systems. Duffy antibodies can cause Haemolytic Disease of Foetus and Newborn (HDFN) and Haemolytic Transfusion Reaction (HTR). Knowledge of the distribution of red cell antigens can help to prevent alloimmunisation and haemolytic transfusion reaction among pregnant women as well as facilitate the optimum stocking of blood banks. In this present study, we investigated the prevalence of Duffy antigens among pregnant women in Sokoto, North Western, Nigeria.

Method: One hundred and sixty two (162) pregnant women aged 18-45 years (Mean age 27.19 ± 4.72 years) attending antenatal clinic in Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto were screened for the presence of Duffy blood group antigens using the conventional tube method and anti-Fya and Fya reagents (Lorne Laboratories, UK).

Result: Out of the 162 pregnant women tested 82 (50.6%) were Hausa, 26 (16%) were Igbo, 23(14.2%) were Fulani and 20 (12.3%) were Yoruba while the minority ethnic groups were 11(6.8%). The distribution of Duffy antigens was compared based on the ethnic groups of subjects. The prevalence of Fya was highest among the minority ethnic groups (9.09%) and lowest among the Yoruba ethnic group (0%). Similarly the prevalence of Fyb was highest among minority ethnic groups (9.09%) followed by the Fulani ethnic group (8.69% and Ibo (7.69%). Lowest prevalence was observed among the Yoruba ethnic group (0%). Majority of the subjects were multigravidae 122 (75.3%) compared to primigravidae 40 (24.7%). The distribution of Duffy antigens among subjects studied indicated a Fya, Fyb and Fya (a+ b+) prevalence of 7 (4.3%), 9 (5.6%) and 1 (0.61%) respectively. A significant number of subject tested negative for Duffy antigens. Of the 162 pregnant women tested, 155 (95.7%), 153 (94.4%) and 148 (91.37%) tested negative for Fya, Fyb and Fy (a-b-) respectively.

Conclusion: This study indicates that blood group antigens can be distributed differently within different nationalities. Duffy phenotypes observed among pregnant women in this study is similar to previous reports among Blacks but at variance with report among Caucasians and Asians. We recommend that detailed routine phenotyping for all clinically significant red cell antigen including Duffy antigen be carried out routinely among all pregnant women in Nigeria. There is also the need to routinely screen all pregnant women for alloantibodies to facilitate the selection of antigen negative units for those with clinically significant alloantibodies who require a red cell transfusion. This can potentially optimise the obstetric management of HDFN and prevent HTR among pregnant women particularly those who have a clinically significant alloantibody.