False-positive HIV in a patient with SARS-CoV-2 infection; a case report

INTRODUCTION: A small portion of Corona Virus disease-2019 (COVID-19) cases associated with co-infections, however occasionally they turn out to be false positive due to possible cross-reactivities. The current report aims to present a rare case of false-positive human immunodeficiency virus (HIV) in a COVID-19 patient. CASE REPORT: A 32-year-old female complaining from thyroid problems referred for thyroid operation. She had mild symptoms of COVID-19. Her preoperative laboratory findings were normal, except for HIV screening test which was repetitively positive. RNA PCR was performed to confirm the diagnosis of HIV, it revealed a negative result. The patient underwent thyroidectomy as planned and was given the required supportive treatment to recover from COVID-19. Two-month follow up revealed that she was negative for COVID-19 on PCR testing, and HIV immunoassay test was no longer positive. DISCUSSION: Due to structural similarities between the spike protein chains of SARS-CoV-2 and some other viruses such as dengue, Zika, and other closely related coronaviruses (SARS-CoV, MERS-CoV), the protein can potentially interfere with the immunoassay tests. Although HIV immunoassay tests have high sensitivity and specificity, false-positive results have been reported, such as in the case of Epstein Barr virus, Influenza vaccination, and the Australian COVID-19 vaccination. CONCLUSION: Similarity between HIV and SARS-CoV-2 spike proteins can lead to antibody cross-reactivities, yielding false-positive results on immunoassay screening tests.