The primary objective is to assess the ability of COVID-19 IgG and IgM assays to detect an immune response in COVID-19 patients in the Henry Ford Health System (HFHS), both during hospitalization and over the following 12 months.

The design strategy for this study is to validate the detection of COVID-19 antibodies in subjects at HFHS who test positive with RT-PCR for SARS-CoV-2 using fully automated test systems already in the core automated laboratory at HFH. This is a study of the immune response and kidney health of subjects who have recovered from COVID-19 infection.

There are 4 aims:

Aim 1. Assess detection of COVID-19 antibodies in subjects before discharge from HFHS who tested positive with RT-PCR for SARS-CoV-2 using fully automated immunoassays.

Aim 2. Evaluate emergence of immunity over a one-year period in subjects who tested positive with RT-PCR for SARS-CoV-2 using a fully-automated immunoassays.

Aim 3. Monitor renal function and kidney health at 6 and 12- months post diagnosis with COVID-19.

Aim 4. Determine if SAR-COV-2 can be detected in the saliva of patients over a one year period after a positive PCR test.

Inclusion Criteria:

• Patients ≥18 years of age
• Positive COVID-19 by RT-PCR SARS-CoV-2 assay
• Patients must have a serum sample stored by pathology or within the TCRC biorepository around the date of their COVID-19 RT-PCR positive test

Exclusion Criteria:

• < 18 years of age
• negative for RT-PCR
• no serum sample

subjects will be identified from a retrospective data review and a laboratory information system (LIS) SunQuest identification of COVID-19 positive (RT-PCR SARS CoV-2) samples or who are already participating in the TCRC collection protocol. This study will recruit subjects in which a baseline serum sample was already obtained either through standard of care procedures or through voluntary participation in the TCRC biorepository.