Detection of specimen contamination in routine histopathology by HLA class II typing using the polymerase chain reaction and sequence specific oligonucleotide probing.

This study evaluates the use of human leukocyte antigen (HLA) class II PCR-SSO typing for the investigation of suspected specimen contamination in four routine surgical histopathology cases. Two cases were of patients undergoing transurethral resection of the prostate gland. The third case was a patient undergoing excision of a subcutaneous small cell carcinoma. The fourth case was a patient undergoing reversal of a Hartman's procedure for adenocarcinoma of the colon. Tissue was extracted from routinely processed formalin-fixed, paraffin-embedded material and HLA class II typed, using a non-radioactive polymerase chain reaction-sequence specific oligonucleotide probe technique (PCR-SSO), using probes specific for the DRB, DQA, and DQB loci. The accuracy of PCR-SSO typing of DNA extracted from paraffin biopsy material was confirmed by concordant results for DRB, DQA, and DQB typing in five separate control individuals from whom frozen and paraffin lymph node biopsies were available. PCR-SSO typing was also successful in the four study cases and revealed that contamination had occurred in two cases, eliminating this possibility in the remaining cases. This study demonstrates that DNA can be reliably amplified and accurately typed from routinely processed material, and reveals a useful new application for PCR-SSO tissue typing.