Influence of Rheumatoid Factors and Bilirubin on the Sensitivity of Immunochromatographic Rapid Diagnostic Tests for HIV/AIDS and Hepatitis B in Cameroon

Aim: We aimed at studying the influence of some potential interference factors on the immunochromatographic Rapid Diagnostic Tests commonly used in Cameroon for the diagnosis of Human Immunodeficiency Virus / Acquired Immune Deficiency Syndrome (HIV/AIDS) and Hepatitis B (HBV) which are major public health problems in the country.
Design and Methods: The sample population of this cross-sectional study included patients referred to the BETHANIE Laboratory for the accurate diagnosis of HIV/AIDS and HBV. RDTs were performed using FIRST RESPONSE HIV Card 1-2.0 and HEXAGON HBsAg. Tests results were confirmed using a high sensitivity 3rd generation ELISA for HIV and HBV, both from FORTRESS. Assays of Rheumatoid Factors and bilirubin were conducted on HIV and HBV samples respectively. Statistical analysis was done using the R software version 3.0.2; the Chi-square test with continuity correction was applied at a threshold of 0.05.
Results: A total of 25 patients were included for the HIV study group and 30 for the HBV group. Test sensitivities of 14.28% and 92.85% for FIRST RESPONSE HIV Card 1-2.0 and HEXAGON HBsAg were found respectively. Average blood levels of RF were 11.55 IU / L and 64.29 IU / L from FIRST RESPONSE HIV RDT positive and negative samples respectively. Blood levels of bilirubin were 88.63 mg / L and 131.66 mg / L from HEXAGON HBsAg RDT positive and negative samples respectively.
Conclusion: HIV FIRST RESPONSE RDT results were independent (P-value = 1.00) of Rheumatoid Factor values (up to 238.8 IU / L). However, we found that HEXAGON HBsAg RDT results were not independent of bilirubin values (P-value = 0.01547), suggesting that the latter could potentially have an influence on the former.