Morphological alterations in minor salivary glands of HTLV1+ patients: A pilot study

Among the complex of HTLV-associated diseases, Sjögren's syndrome (SS) is one of the most controversial. This work aims to detect morphological and inflammatory alterations, including clues of the presence of HTLV-1, in minor salivary glands of patients with dryness symptoms.

We have assessed HTLV-1-seropositive patients (HTLV-1 group) and patients with SS (SS group). We used formalin-fixed, paraffin-embedded minor salivary gland tissue to evaluate the morphological aspects and, by means of immunohistochemistry, the presence of Tax protein, CD4, CD8 and CD20 cells. Additionally, viral particles and proviral load were analysed by PCR.

The HTLV-1 group had the highest prevalence of non-specific chronic sialadenitis (85.71%; P = 0.017) and greater amount of T CD8⁺ cells. In the SS group, focal lymphocytic sialadenitis (80%; P = 0.017) prevailed, with a greater amount of B CD20⁺ . Both immunohistochemistry and PCR identified the Tax protein and its gene in the salivary glands of both groups and in similar proportions.

The results indicate that HTLV-1-seropositive patients have different patterns of morphological/inflammatory alterations, suggesting a likely difference in the process of immune activation.