CD4(+) T cells participate in the nephropathy of canine visceral leishmaniasis

Renal involvement in visceral leishmaniasis (VL) is very frequent. The rena l lesions of humans and dogs are similar but their pathogenesis has not bee n clearly elucidated. There is growing evidence that the cellular immune re sponse is involved in the pathogenesis of immunologically mediated glomerul onephritis. Since T cells could participate in the pathogenesis of nephropa thy, in the present study we investigated the possible involvement of CD4() and CD8(+) T cells in the nephropathy of canine VL. Six dogs naturally in fected with Leishmannia (Leishmania chagasi from the endemic area in the No rtheast of Brazil, the town of Teresina in the State of Piaui, were studied . An expressive inflammatory infiltrate of CD4(+) T cells both in glomeruli and in interstitium was present in 4 animals and absent. in 2. CD8(+) T ce lls were detected only in one animal. CD4(+) T cells alone were observed in 3 animals; when CD8(+) T cells were present CD4(+) T cells were also prese nt. CD4(+) T cells were observed in cases of focal segmental,glomeruloscler osis, diffuse membranoproliferative glomerulonephritis, diffuse mesangial p roliferative glomerulonephritis and crescentic glomerulonephritis. CD8(+) T cells were present only in a case of crescentic glomerulonephritis. Leishm ania antigen was detected in glomeruli and in interstitial inflammatory inf iltrate in 4 animals and immunoglobulins were observed in 4 dogs, in this s tudy we observed that T cells, in addition to immunoglobulins, are present in the renal lesion of canine VL. Further studies are in progress addressin g the immunopathogenic mechanisms involving the participation of immunoglob ulins and T cells in canine VL nephropathy.