RESEARCH - Absence of RA in a rural Nigerian population

[Guest guest]

J Rheumatol. 1993 Apr;20(4):618-22.

Absence of rheumatoid arthritis in a rural Nigerian population.

Silman AJ, Ollier W, Holligan S, Birrell F, Adebajo A, Asuzu MC,

Thomson W, Pepper L.

Arthritis and Rheumatism Council Epidemiology Research Unit,

University of Manchester, UK.

A 2-stage population screening survey of 2,000 inhabitants of 2 rural

townships in southern Nigeria was undertaken. No case of rheumatoid

arthritis (RA) was discovered in those responding, although 3 cases of

inflammatory polyarthritis were found. One of these individuals

satisfied the modification of the American College of Rheumatology

classification tree criteria that allows for missing radiographic

data. Simultaneous monitoring, during a 4-month period, of the local

health clinic serving the townships also failed to reveal a case of

RA. Three (5.5%) of 55 individuals tested were positive for rheumatoid

factor, a rate lower than in previous surveys of rural West African

populations. Further immunogenetic investigation of that subsample

from this population, using HLA oligonucleotide typing, suggested that

HLA-DR4 was rare (1/55). Further, although HLA-DR1 was present in 7

(13%), 6 had the DRB1*0102 variant seen in black populations and not

thought to be associated with RA. Our study confirmed the findings of

others that rural African groups have extremely low rates of RA. In

addition HLA genes containing the RA associated " shared epitope " are

also relatively infrequent and might explain this reduction in RA

prevalence.

PMID: 8496853

http://www.ncbi.nlm.nih.gov/pubmed/8496853

Not an MD