Increased double marker lymphocytes in systemic lupus erythematosus and lymphoproliferative disorders.

In this study we were able to confirm the presence of double marker lymphocytes (D cells) in human peripheral blood from normal subjects in addition to patients with SLE and malignant lymphoma. Quantitation of D cells and Null lymphocytes (N cells) in peripheral blood was not feasible via conventional rosette methods. The present combination method, using two indicators, neuraminidase treated sheep red blood cells (nSRBC) and Immunobeads, allows for simultaneous demonstration of T, B, N and D lymphocytes in a simple reproducible manner. The mean percentage of the D cell counts with this method was 1.8% of total lymphocytes from normal donors, 7.0% in patients with SLE, and 29.2% in patients with malignant lymphoma. The simultaneous quantitation of T, B and N cells in these blood samples was compared to the results of conventional methods, i.e. E rosettes for T cells and EAC rosettes for B cells, which gave similar results. This combination method for simultaneous enumeration of human peripheral lymphocyte subpopulations may offer significant advances in the study and diagnosis of various clinical entities.