The spleen is the graveyard of CD4+ cells in patients with the immunological failure of visceral leishmaniasis and AIDS

Abstract

Background Visceral leishmaniasis (VL), or kala-azar, is a common comorbidity of patients with AIDS in endemic areas. Many patients continue to develop relapses of VL, nevertheless with virological control but with immunological failure. Because they remain chronically symptomatic with anemia, leucopenia, thrombocytopenia, and at risk of severe coinfections due to low CD4 + count, 11 coinfected patients underwent splenectomy as a salvage therapy. The spleen's red pulp filters and clears blood elements, while the white pulp is lymphoid tissue. Methods This study compared the patient's complete blood cell counts (CBC), CD4+, and CD8 + cells before and after splenectomy and with the spleen weight. Results There was a substantial improvement in CBC after splenectomy, indicating hypersplenism. However, to our knowledge, this is the first study to show that the spleen mass is strongly and negatively correlated with CD4 + cell count (r = 0.72, p-value = 0.013). Conclusion The finding was unexpected since the spleen is the most extensive lymphoid tissue and T-lymphocyte source. After reviewing the literature, we concluded that the immunological failure was secondary to CD4 + loss initially by apoptosis in the spleen induced by productive HIV infection and lately by pyroptosis sustained by the parasitic infection in spleen macrophages.