Successful treatment of tubulointerstitial nephritis and uveitis with steroid and azathioprine in a 12-year-old boy

Tubulointerstitial Nephritis and Uveitis Syndrome in the United Arab Emirates

PURPOSE

To report the first series of tubulointerstitial nephritis (TINU) syndrome from the Middle East.

METHODS

We retrospectively included patients with elevated urine beta-2 microglobulin, and a diagnosis of TINU based on anterior uveitis with or without posterior involvement. Multimodal imaging, duration of follow-up, local and systemic treatment used were recorded.

RESULTS

24 eyes of 12 patients (8 male, mean age 20.3 years) met the criteria for TINU. The most common posterior segment clinical finding was optic nerve head edema (41.7%), while on fluorescein angiography 58.3% and 75% of eyes had peripheral vascular and optic disc leakage, respectively. The mean follow-up was 2.5 years and all patients required immunomodulatory treatment.

CONCLUSIONS

Middle Eastern patients with TINU seem to have a male predominance, a bimodal distribution in terms of age, and present with ocular involvement first. Multimodal imaging is paramount in detecting subclinical inflammation and tailoring immunomodulatory treatment.

Renal outcomes in tubulointerstitial nephritis and uveitis (TINU) syndrome: a systematic review and meta-analysis

BACKGROUND

Tubulointerstitial nephritis and uveitis syndrome (TINU) is a rare condition characterised by bilateral uveitis and interstitial nephritis. There is no nationally, or internationally agreed upon treatment regimen. A systematic review was undertaken to report the renal outcomes in TINU, and treatments used.

METHODS

Medline (1969-2021) and EMBASE (1988-2021) databases were searched for primary studies, clinical practice guidelines and case reports of adult and paediatric TINU cases, as defined by Mandeville criteria. Two reviewers identified articles meeting inclusion criteria (registered with PROSPERO). Data were extracted into a synthesis table and meta-analysis performed. Quality of case series was also assessed.

RESULTS

One hundred twenty-two articles were identified, totalling 257 cases included in the meta-analysis. Females were more commonly affected than males (2:1), and median age was 19 years. GFR at follow-up correlated with nadir GFR, and the proportion with GFR <90 ml/min/1.73 m² was statistically different between adult and paediatric groups. Of the entire cohort, 40% had GFR <90 ml/min/1.73 m² at follow-up. Glucocorticoid monotherapy was the most common treatment (70%); other strategies included no treatment (9%) and immunosuppressant drugs (e.g. azathioprine), mostly in steroid-resistant cases, or as 'steroid-sparing' alternatives.

CONCLUSIONS

The majority of literature regarding TINU is limited to case reports and case series. There are no prospective trials assessing the effects of different treatments on renal outcomes, and currently employed treatment strategies are physician-specific without a reliable evidence-base. Prospective data collection as part of multicentre trials should be a research focus to improve the evidence-base.

Tubulointerstitial nephritis and uveitis syndrome: a systematic review

BACKGROUND

Tubulointerstitial nephritis and uveitis (TINU) syndrome is defined as the occurrence of tubulointerstitial nephritis (TIN) and uveitis in the absence of other systemic diseases. The most comprehensive review on this condition was published in 2001.

METHODS

We conducted a systematic review of the literature for cases of TINU syndrome. MEDLINE and Embase databases were screened. Full-length articles or letters reporting cases with both TIN and uveitis were selected. We investigated differences between males and females and paediatric and adult cases. Multivariate analysis was performed to identify potential risk factors for chronic kidney disease (CKD) development.

RESULTS

A total of 233 articles reporting 592 TINU cases were retained for the analysis. The median age of the included subjects was 17 years (interquartile range 13-46) with a female predominance (65%). Uveitis most frequently (52%) followed renal disease and was mostly anterior (65%) and bilateral (88%). Children tended to have more ocular relapses, while they were slightly less likely than adults to suffer from acute kidney injury and to develop CKD. Adult age as well as posterior or panuveitis were associated with an increased risk of developing CKD.

CONCLUSIONS

TINU affects both children and adults, with some differences between these two categories. Adult age and the presence of a posterior uveitis or panuveitis appear to be associated with the development of CKD.

Acute Kidney Injury Relevant to Tubulointerstitial Nephritis with Late-Onset Uveitis Superimposed by Thrombotic Microangiopathy: A Case Report and Review of the Literature

Background

The syndrome of tubulointerstitial nephritis and uveitis (TINU) is an uncommon and multisystemic autoimmune disorder. This review reports a rare case of TINU being superimposed on thrombotic microangiopathy (TMA) and, by comparing with the available literature, also summarizes the clinical features, associated conditions, treatment, and outcome of patients with TINU.

Summary

Herein, we report the case of a 37-year-old male patient with acute kidney injury (AKI) clinicopathologically identified as malignant hypertension-induced TMA superimposed by acute tubulointerstitial nephritis, which was suspected to be related to drug hypersensitivity. After treatment with oral prednisone combined with a renin-angiotensin system inhibitor, the patient achieved partial renal recovery and was withdrawn from hemodialysis. Recurrent AKI concomitant with new-onset asymptomatic uveitis was detected during routine clinical follow-up after cessation of prednisone. TINU was then diagnosed, and prednisone followed by cyclophosphamide was prescribed. The patient achieved better renal recovery than in the first round of treatment and maintained stable renal function afterward. By reviewing the literature, 36 cases were reported as TINU superimposed on other conditions, including thyroiditis, osteoarthropathy, and sarcoid-like noncaseating granulomas.

Key messages

TINU could be complicated by many other conditions, among which TMA is very rare. When presented as AKI, kidney biopsy is important for differential diagnosis. The case also shows that recurrent AKI with concomitant uveitis after prednisone withdrawal strongly suggested the need for long-term follow-up and elongated prednisone therapy for TINU syndrome.

Tubulointerstitial nephritis and uveitis syndrome in children: report of three cases

Tubulointerstitial nephritis and uveitis syndrome is a rare and probably underdiagnosed condition. Renal and ocular manifestations may not occur simultaneously, making the diagnosis more difficult. Nephritis may be asymptomatic; therefore, renal function evaluation is essential for diagnosis. Urinary β2-microglobulin levels may be particularly useful. Uveitis, mostly anterior, nongranulomatous and bilateral, occurs usually after the onset of nephritis. Treatment includes corticosteroids and, eventually, other immunosuppressant agents. Renal disease is usually benign and resolves spontaneously or after treatment with systemic corticosteroids. Uveitis, however, may be chronic or recurrent. The authors described the cases of three pediatric patients diagnosed with tubulointerstitial nephritis and uveitis syndrome. The goal of this paper was to warn the medical community over the need to screen patients with uveitis for renal disease.