Objective: To evaluate the use of a polymerase chain reaction (PCR) method for detection of feline immunodeficiency virus (FIV) DNA, using formalin-fixed paraffin-embedded (FFPE) tissues, and to use this method to evaluate tissues obtained from vaccine site-associated sarcomas (VSS) of cats for FIV DNA.
Sample population: 50 FFPE tissue blocks from VSS of cats and 50 FFPE tissue blocks from cutaneous non-vaccine site-associated fibrosarcomas (non-VSS) of cats.
Procedure: DNA was extracted from FFPE sections of each tumor and regions of the gag gene of FIV were amplified by a PCR, using 3 sets of primers. Sensitivity of the method was compared between frozen and FFPE tissues, using splenic tissue obtained from a cat that had been experimentally infected with FIV.
Results: We did not detect FIV DNA in VSS or non-VSS tissues. Sensitivity of the PCR method was identical for frozen or FFPE tissues.
Conclusions and clinical relevance: It is possible to detect FIV DNA in FFPE tissues by use of a PCR. We did not find evidence to support direct FIV involvement in the pathogenesis of VSS in cats.