Joint fluid cytology in Reiter's disease

The diagnostic value of the finding of cytophagocytic macrophages (CPM) in the joint fluid of patients with Reiter's disease has been re-examined. CPM were found in 46% of Reiter's disease fluids and in 45% of other inflammatory knee joint fluids. Higher CPM scores, on a 4-point grading, were commoner in Reiter's disease but the difference was not statistically significant. Further, although the graded polymorphonuclear leucocyte phagocytosis shown by CPM was greater in Reiter's disease this also was not significant. It is concluded that the presence of CPM in joint fluid is of little discriminating value.