Viral Tax protein expression in salivary glands of patients infected with human t-cell lymphotropic virus type I and Sicca Syndrome

Background: Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that influences cellular metabolism modifying biological responses. This results in oncogenic, degenerative or inflammatory changes. The myelopathy associated to HTLV-1 or tropical spastic paraparesia (HAM/TSP) is a mainly degenerative response to the virus infection. On the other hand, Sjogren syndrome has an inflammatory appearence. The immunohistochemical study of CD-4, CD-8 and CD45 lymphocytes, metalloproteinase MMP-9 and viral Tax protein in pathological samples of salivary glands may help to differentiate primary from viral Sicca syndrome. Aim: To perform an immunohistochemical study of salivary glands of patients with HAM/TSP and Sicca syndrome and control subjects. Material and Methods: Pathological samples of salivary glands from 53 patients with HAM/TSP and Sicca syndrome and 10 control subjects, were studied. Immunohistochemistry was performed using antibodies against CD-4, CD-8 and CD-45 lymphocytes, metalloproteinase MMP-9 and viral Tax protein. Results: Only in patients with HAM/TSP and Sicca syndrome, the presence of Tax protein was observed in Cd-4 and CD-8 lymphocytes and in glandular acini. Conclusions: Patients infected with HTLV-1 express Tax protein in salivary glands. This finding has diagnostic and pathogenic implications (Rev Med Chile 2005: 133: 1183-90).