engleski

THE POOR QUALITY OF CADAVERIC CORNEA SPECIMENS = A LOT OF FALSELY POSITIVE RESULTS IN SEROLOGICAL TESTING

Background: Serological testing of cadaveric cornea donors in Croatia includes HBsAg, anti-HCV, anti-HIV-1/2, anti-TP and anti-HBc (if positive, anti-HBs is performed). Cadaveric specimens are collected at variable times after death, often of poor quality (haemolysed or autolyzed) and frequently yield falsely positive results in serological testing. Although Abbott Architect assays (HBsAg Qualitative II, Anti-HCV, HIV Ag/Ab Combo, Syphilis TP and Anti-HBc II) are validated for cadaveric specimens, we found a lot of unspecific reactions and implemented confirmatory testing algorithms. Methods: From 2016 till October 2018, we got 643 different cadaveric specimens, from the Eye Bank – University Hospital Centre Zagreb. Initial tests used are named Abbott Architect tests. The following tests were used to decide on false or correct positive results: for HBsAg: Bio-Rad Monolisa HBsAg Ultra, Architect Confirmatory test, Vidas HBsAg ULTRA ; for anti-HCV: Vidas Anti-HCV, Bio-Rad Monolisa HCV Ag-Ab Ultra v2 Combo, immunoblot (Mikrogen and/or Fujirebio) ; for HIV Ag/Ab: Dia.Pro HIV Ab&Ag, Vidas HIV DUO ULTRA, immunoblot (Mikrogen and/or Fujirebio), Vidas HIV P24 ; for anti-TP: Dia.Pro Syphilis Ab v. ULTRA, TPHA, RPR, immunoblot (Mikrogen and/or Fujirebio), Dia.Pro Syphilis IgM ; for anti-HBc: Dia.Pro HBcAb and Vidas Anti-HBc Total II. Results: The total falsely positives of Architect tests were found in 3% (19/634) of HBsAg, 0.3% (2/634) of anti-HCV, 4.7% (30/634) of HIV Ag/Ab, 0.3% (2/634) of anti-TP and 0.6% (4/634) of anti-HBc results. Conclusions: The observed specificity data of the Architect tests used for the initial cadaveric specimen testing show that the highest proportion of falsely positive results is in HIV Ag/Ab test, then HBsAg, anti-HBc and anti-TP/anti-HCV, respectively. Implemented confirmation testing algorithms saved in given period the total of 57 corneas from needlessly discard and assure the supply and safety of corneas for transplantation.

cadaveric cornea donors, serological testing

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