Stability of anti-HIV antibodies in serum samples stored for two to eighteen years periods

Abstract

Introduction: The antibodies have an important role in the serodiagnosis, constituting the most widely used biomarkers to detect and confirm various diseases. Objective: To investigate the reproducibility of anti-human immunodeficiency virus (HIV) antibodies reactivity, to assess the stability of the sera samples stored at -20ºC for two to eighteen years. Method: Sera were collected in the period 1988-2004 for routine anti-HIV antibodies diagnostic testing. The remaining samples stored at -20ºC, were analyzed in this study. Serum sample stability was assessed by enzyme-linked immunosorbent assay/enzyme immunoassay (ELISA/EIA), indirect immunofluorescence assay (IFA), and Western blot (WB) for detecting anti-HIV antibodies. The previously found results (1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004) and those obtained in 2006 were subjected to Kappa index analysis. Result: In the period 1988-to 2004, the degree of concordance of the ELISA/EIA, IFA and WB results were considered, good (k = 0.80), regular (k = 0.35), and good (k = 0.63), respectively. Conclusion: Regarding HIV serologic test, the serum samples were stable for 18 years in ELISA/EIA and for 4 years in IFA technique, however, for the WB methodology it was not possible to determine the time of stability of the anti-HIV antibodies.

Comparison of fixed cell-based assay to radioimmunoprecipitation assay for acetylcholine receptor antibody detection in myasthenia gravis

“…It is possible that some alteration of antigen conformation during the fixation procedure impacts sensitivity, like has been suggested for F-CBA used to detect other antibodies [5]. Alternatively, the long duration of sample storage prior to F-CBA testing could have hindered anti-AChR detection due to sample degradation [13]. This may also account for the 1% of MG patients that were RIPA-positive but F-CBA-negative, despite overall higher sensitivity of F-CBA.…”

Anti-drug Antibody Validation Testing and Reporting Harmonization

“…Long-term stability is not required as several published studies from vaccine research, as well as internal industry studies, document that immunoglobulins are stable for several years when maintained under controlled storage conditions (38,39). Additional reports from diagnostic immunology further support general stability of antibodies (40)(41)(42)(43).…”

Stability of Zika Virus Antibodies in Specimens from a Retrospective Serological Study

“…In general, antibodies are known to remain stable in frozen storage over lengthy periods. There are numerous publications regarding antibody stability during storage, 2 – 6 and we believe that all antibodies, including antibodies against Zika virus, will remain stable during storage.…”