To investigate the occurence of various autoantibodies in the Omani population.

Sera from 392 healthy Omani individuals comprising 183 pregnant women and 209 blood donors (183 men and 26 women) were investigated. Autoantibodies were detected using immunofluorescence, haemagglutination and latex agglutination techniques.

Low levels of autoantibodies were detected in approximately 50% of the subjects; very few subjects showed high autoantibody titres. Anti smooth muscle autoantibodies (ASMA) were the most prevalent, and were detected in 31.6% of the individuals. Anti thyroid microsomal autoantibodies (ATMA) and anti thyroglobulin autoantibodies (ATA) were present in 5.9% and 4.9% of individuals respectively. The other autoantibodies were detected much less frequently, viz. anti nuclear autoantibodies (ANA) in 1.5%, anti parietal cells autoantibodies (APCA) in 1.8%, anti reticulin autoantibodies patterns (ARAP) in 3.0% and rheumatoid factor (RF) in 1.0% of the subjects.

The data indicate that autoantibodies do exist in healthy Omani individuals and the results of clinical tests for these autoantibodies must be interpreted with caution.