COMPARATIVE ANALYSIS OF HISTOLOGICAL AND IMMUNOHISTOCHEMICAL PICTURE OF LYMPH NODES IN HIV INFECTION

Background. Structural changes in the lymph nodes (LNs) in HIV infection correspond to the clinical syndrome – persistent generalized lymphadenopathy (PGL), which is a fairly reliable clinical sign of HIV infection. As a result of prolonged PGL in the germinal centers of the lymph nodes, cytopathic destruction of immunocompetent cells occurs, leading to their involution. The goal is to establish histological and immunohistochemical parallels in LN at different clinical stages of HIV infection. Material and methods. The object of the study was 48 LNs of various locations from 13 dead HIV-infected patients in Svetlogorsk district of Gomel region in 2018, as well as 4 LNs after an excisional biopsy of 4 patients from this region. Before immunohistochemical examination (IHC), all histological preparations were studied by light microscopy using staining with hematoxylin and eosin (H&E), which enabled to assess the state of structural elements in the lymph nodes. IHC of lymph nodes was performed using the following antibodies (manufactured by Roche Diagnostics, USA): rabbit monoclonal primary antibodies to CD3 (2GV6), CD4 (SP35), CD10 (SP67), bcl-2 (SP66), as well as mouse monoclonal primary antibodies CD20 (L26), CD21 (2G9). The IHC study was performed using a VentanaBenchMark GX IHC / ISH automatic immunohistostainer. Results. In most cases, the relationship and the coincidence of histological and immunohistochemical changes in the LNs taking into account the stage of PGL were established. The revealed changes corresponded to successive stages of PGL from severe hyperplasia of lymphoid follicles with wide germinal centers at the initial stages of infection to hypoplasia of reproduction centers and complete atrophy of lymphoid follicles (lymphocytic depletion), which is reflected in the illustrations. The reproducibility control of the results of the PGL stages according to the IHC results was 100%, in contrast to light microscopy, the results of which corresponded to the PGL stages in 82.3%. Conclusions. The histological picture of LNs in patients with HIV infection in most cases correlates with the immune status data, but it does not have absolute value in the diagnosis of PGL stage. The IHC study has higher reliability and reproducibility than a histological study in determining the stages of PGL. A complex method of histological and immunohistochemical studies improves the quality of diagnosis of HIV infection in general.