HLA and nonspecific polyarthritis in the highlands of Papua New Guinea.

We have studied the HLA profile of a series of 49 patients (32 men, 17 women) presenting with asymmetric polyarthritis to the Goroka Base Hospital, Papua New Guinea. Antigens A11 and B27 were found to be significantly increased in patients when compared with a control sample of 100 healthy Papua New Guinean highlanders. Significant negative associations were also recorded with A24[A9] and Bw22. None of the patients studied presented with the complete triad of Reiter's disease although 6 patients, all men, had some extraarticular symptoms. On the basis of these additional symptoms, the 6 patients were diagnosed to have an incomplete form of Reiter's disease and were excluded from further comparisons. In the remaining 43 patients, who fit the nonspecific category that has been called tropical polyarthritis, B27 was present in 20.9% of the cases, which was not significantly different from the control frequency of 11.0%. But the positive association with A11 was still found in the nonspecific arthritis cases. Our data do not support the concept that the patients included in this study constitute a single diagnostic category which is related to Reiter's disease. It is suggested that these patients be regarded as suffering from nonspecific polyarthritis of unknown, probably multiple, aetiology, until further more specific diagnostic entities can be determined.