The effect of FIV infection on CD4(+) and CD8(+) counts in periradicular lesions

Aim The purpose of this study was to elucidate whether a decrease/increase in T-cell populations is present in the development of periradicular diseas e in the immunocompromised feline model. Methodology Eight cats were immunosuppressed with steroids prior to infecti on with feline immunodeficiency virus (FIV). Another eight cats, age and se x matched littermates, were monitored and tested at equivalent periods of t ime and served as uninoculated, seronegative controls. Periradicular lesion s were induced using local bacterial inoculations into the pulp of the cani ne teeth and assessed after one- and four-week periods, corresponding to th e acute and chronic stages of the periradicular disease. Block sections wer e obtained and specimens were prepared for H & E and immunohistochemical st aining for CD4(+) and CD8(+) receptors. Cells were quantified using a compu ter imaging system and data analysed using generalized estimating equation (GEE) regression models. Results Significantly lower CD4(+) counts and CD4(+)/CD8(+) ratios were obs erved at all time periods in the periradicular region of the FIV group (P = 0.0006). No significant difference in CD8(+) counts was observed between t he two groups. In both groups there was a significant difference in the CD4 (+) counts between one week and baseline, and 1 week and 4 weeks. There was no significant difference between baseline and 4 weeks for either group. Conclusion FIV infection reflected decreased CD4(+) counts at the periradic ular level, however, inflammation and progression of the lesion. appeared t o be comparable to the non-immunocompromised controls.