HISTOPATHOLOGICAL, LYMPHOSCINTIGRAPHICAL, AND IMMUNOLOGICAL CHANGES IN THE INGUINAL LYMPH-NODES OF RHESUS-MONKEYS DURING THE EARLY COURSE OF INFECTION WITH BRUGIA-MALAYI

The relationship of the early lymphatic pathophysiological alterations with those of tissue inflammatory and cellular responses in the ingui nal lymph nodes of Brugia malayi-infected rhesus monkeys was examined. Each of five animals was inoculated subcutaneously in the right calf with 200 third stage larvae (L-3) and 5 weeks later, before the onset of patency [10 to 12 weeks postinoculation (PI)], their right inguinal nodes began to show signs of enlargement, becoming most prominent bet ween weeks 10 to 16 PI. Histopathologically, the right nodes had eosin ophilic lymphadenitis, lymphoid hyperplasia, and pronounced germinal c enters. Lymphoscintigraphy using Tc-99m-antimony trisulfide colloid sh owed pathophysiological alterations of the lymph flow rate in the righ t leg but not in the left leg at weeks 7 and 15 PI. In vitro blastogen esis to B. malayi antigens at week 10 PI showed the inguinal lymph nod e cells proliferated more vigorously than did peripheral blood cells e arly in infection. However, at week 24 PI both lymph node and peripher al blood cells proliferated to antigens. Flow cytometry showed an upre gulation of HLA-DR+ lymphocytes in right lymph node cells from infecte d animals when compared to those from control animals. No changes in C D2, CD4, CD8, CD20, CD29, and CD45R cell numbers in lymph node of infe cted animals were seen when compared to control animals. Our results s how that lymphatic pathology occurs early before the onset of patency, correlating with a marked tissue inflammatory and cellular responses of lymph node cells in B. malayi-infected rhesus monkeys. The rhesus c ould be an extremely useful model for understanding the evolution of p athology and pathogenesis of the disease. (C) 1998 Academic Press.