Tubulointerstitial nephritis and uveitis syndrome (TINU) following COVID-19 vaccination

Tubulointerstitial nephritis and uveitis post COVID-19 infection in an adult

A woman in her 50s contracted COVID-19 and initially presented a few weeks afterwards with left eye pain and redness. She was diagnosed with uveitis and treated with glucocorticoid eye drops. Renal impairment was found on laboratory investigations performed following the diagnosis of uveitis, and urine testing showed proteinuria. Serological testing showed no cause for the new findings, and renal imaging was unremarkable. A renal biopsy was conducted and histology was consistent with tubulointerstitial nephritis. A diagnosis of tubulointerstitial nephritis with uveitis (TINU) was established, and she was given prednisolone, with resolution of proteinuria and improvement in renal function. While TINU is rare but well described in children, it can also uncommonly be a cause of renal impairment in adults post COVID-19 infection, similar to cases in children.

Tubulointerstitial Nephritis and Uveitis Syndrome During the COVID-19 Pandemic: A Case Series

Objectives

To report the ocular findings, laboratory results, and management of patients with tubulointerstitial nephritis and uveitis syndrome (TINU), whose numbers increased during the 2019 coronavirus disease (COVID-19) pandemic.

Materials and Methods

Demographic characteristics, ophthalmic examination findings, laboratory results including polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), serum SARS-CoV-2 immunoglobulin G (IgG) antibody, and treatment of patients diagnosed with TINU between March 2020 and March 2022 were evaluated retrospectively.

Results

The study included 19 eyes of 10 patients (6 female/4 male). The mean age was 13.5±2.4 years (range: 8-16 years). The mean follow-up duration was 13.5±6.1 months (range: 6-24 months). All patients presented with anterior uveitis. Anterior uveitis was bilateral in 9 patients (90%) and unilateral in 1 patient (10%). Posterior segment findings were normal in 8 patients (80%), and bilateral optic disc edema was observed in only 2 patients (20%). None of the patients had a previous SARS-CoV-2 infection and/or vaccination history. The SARS-CoV-2 PCR test was negative in all patients at presentation. The SARS-CoV-2 IgG antibody test was reactive in 7 patients (70%). Recurrent uveitis developed in 8 patients (80%) during follow-up. Systemic immunomodulatory therapy was required for the control of ocular inflammation in 7 patients (70%) with severe uveitis flare-ups.

Conclusion

TINU is a multisystemic autoimmune disease, especially in response to environmental triggering factors such as viral infections. Although TINU is a rare disease, the number of cases increased during the COVID-19 pandemic. SARS-CoV-2 antibodies were detected at a significant rate of 70% in these patients, who did not have a history of SARS-CoV-2 infection and vaccination. Previous asymptomatic SARS-CoV-2 infection in children may be a triggering factor in the development of TINU.