Association of ABO and Rh D blood groups with rheumatoid arthritis amongst the elderly in Port Harcourt Metropolis

Abstract

Background: Rheumatoid arthritis which is an autoimmune disease is a health problem and it is strongly correlated or associated with  modifiable risk factors such as presence or absence of blood group antigens amongst other factors.

Aim: This study aimed at  determining the association of ABO and Rh D blood groups with rheumatoid arthritis amongst the elderly in Port Harcourt Metropolis.  

Methodology: A total of one hundred (100) human subjects aged 45–90 years were recruited for the study. Blood samples were collected  through venipuncture for the determination of ABO/Rh D blood groups and Rheumatoid factor. The study was carried out within the  period of 13th August, 2023 to 27th September, 2023. ABO and Rh D blood grouping were determined manually with reagents  manufactured by Atlas Medical, Cambridge. Rheumatoid arthritis (rheumatoid factor) was determined manually with latex reagents  manufactured by Spectrum for Diagnostic Industries, Ismalia, Egypt. Results were statistically analyzed by calculation of percentages, odd  ratios, relative risks and likelihood ratios using Graph-pad prism, version 8.

Results: The results revealed female subjects were 51%,  while male subjects were 49%. The prevalence of Rh D positive was 95%, while Rh D negative was 5%. Blood group O has the highest  frequency of (59) 59% followed by A with frequency of 33 (33%) then B 7 (7%) and AB 1 (1%). The odd ratio (OR) and likelihood ratio (LR)  from the study revealed the following: blood group B (OR = 5.31, LR = 4.08); A (OR = 0.06, LR = 0.09); O (OR = 0.03, LR = 0.08); and AB (OR =  0.00, LR = 0.00). For Rh D blood groups: Rh D negative individuals recorded OR = 4.75, LR = 4.00; while Rh D positive individuals recorded  OR = 0.002, LR = 0.06.

Conclusion: Distribution of ABO and Rh D blood groups amongst the studied subjects is in the order of O>A>B>AB  and Rh D+ > Rh D–. Gender is not a risk factor for Rheumatoid Arthritis in the studied population. Based on the odd and likelihood ratio,  the likelihood for rheumatoid arthritis to occur amongst the blood groups under study, is in the order of B>A>O>AB, and Rh D– > Rh D+,  which is suggestive that Rh D+ individuals may be associated with less risk for rheumatoid arthritis, and blood group B individuals may be  associated with high risk of developing rheumatoid arthritis.