Long-term clinical characteristics and renal prognosis of children with tubulointerstitial nephritis and uveitis syndrome

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.

Ocular manifestations and clinical outcomes in Tubulointerstitial Nephritis and Uveitis Syndrome (TINU)

PURPOSE

To describe the various ocular clinical features and visual outcomes in Tubulointerstitial Nephritis and Uveitis Syndrome (TINU).

METHODS

The medical records of 13 patients (26 eyes) diagnosed with TINU were reviewed.

RESULTS

Twenty-six (26) eyes of 13 patients with TINU were reviewed in this study. The median age at onset of uveitis was 14 (range, 9-45). Eight (61.5%) subjects were female. The median follow-up of patients was 30 months (range, 6-89 months). Posterior segment findings were seen in 18 eyes of 9 patients (69.2%). The most common posterior findings were optic nerve head inflammation (16 eyes, 88.8%) and retinal vasculitis (13 eyes, 72.2%). Other posterior findings included vitritis (8 eyes, 44.4%), macular edema (6 eyes, 33.3%), snowball (4 eyes, 22.2%), and chorioretinal lesions (2 eye, 11.1%). Eight patients had fluorescein angiography (FA) data available and most eyes had retinal capillary leakage (13 eyes, 81.2%) followed by optic disc staining/leakage (12 eyes, 75%). Twelve (12) patients (92.3%) were treated with immunomodulatory treatment (IMT) and/or biologics. Five patients (%38.4) required biologics to control intraocular inflammation.

CONCLUSION

Posterior segment involvement may be common in patients with TINU syndrome. FA provides significant information for detecting posterior segment involvement and disease activity in TINU. The majority of patients required systemic treatment in order to control intraocular inflammation and prevent relapses.

Renal Prognosis in Children With Tubulointerstitial Nephritis and Uveitis Syndrome

Introduction

Tubulointerstitial nephritis (TIN) and uveitis (TINU) syndrome is a rare disease. The renal prognosis is generally thought to be better in children with TINU syndrome than in adults. However, data are scarce. We aimed to investigate the long-term renal prognosis in a French cohort of children with TINU syndrome.

Methods

We performed a national retrospective study including 23 French pediatric nephrology centers enrolling patients with TINU syndrome diagnosed between January 2000 and December 2018.

Results

A total of 46 patients were included (52% female, median age 13.8 years). At diagnosis of TIN, the median estimated glomerular filtration rate (eGFR) was 30.6 ml/min per 1.73 m² (4.9–62.8). The median time between diagnosis of uveitis and TIN was 0.4 months (−4.1; +17.1). All patients had anterior uveitis, but 12 (29%) were asymptomatic. Nearly all patients (44 of 46) received steroid treatment, and 12 patients (26%) received a second-line therapy. At last follow-up (median 2.8 years), the median eGFR was 87.5 ml/min per 1.73 m² (60.3–152.7) and <90 ml/min per 1.73 m² in 20 patients.

Conclusion

In our study, nearly half of the patients had renal sequelae at last follow-up. Given the possible progression to chronic kidney disease, long-term monitoring of children with TINU syndrome is mandatory. Approximately a quarter of the children had asymptomatic uveitis suggesting all children presenting with TIN should undergo systematic ophthalmologic screening even in the absence of ocular signs.