Tubulo-interstitial nephritis and uveitis syndrome in a 6-year-old boy: case report

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.

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

Tubulointerstitial nephritis and uveitis (TINU) syndrome is a rare disease, often underdiagnosed or misdiagnosed in children. We describe the case of a 12-year-old boy who presented to Severance Hospital with a 1-month history of bilateral conjunctival injection. He was first evaluated by an Ophthalmologist in another hospital and diagnosed with panuveitis. Laboratory tests indicated renal failure, and a renal biopsy confirmed the diagnosis of acute tubulointerstitial nephritis. An extensive exclusion of all possible causes allowed a diagnosis of TINU syndrome. The patient was treated with a systemic corticosteroid (initially prednisolone, 2 mg/kg and later deflazacort 1 mg/kg) and topical steroid drops for 1 month. Azathioprine was later added to the treatment regimen and the systemic steroid was slowly tapered. The final outcome of renal-ocular disease was favorable in the patient. However, long-term follow-up is necessary to properly manage frequent relapses and incomplete renal recovery. TINU should be considered as a differential diagnosis in children with uveitis or acute renal failure.

Tubulointerstitial nephritis with uveitis in Chinese adults

BACKGROUND AND OBJECTIVES

Tubulointerstitial nephritis and uveitis (TINU) syndrome is considered a rare cause of acute tubulointerstitial nephritis (ATIN) that is usually associated with renal recovery. This study sought to investigate the diagnosis, prognosis, and contributing factors of TINU syndrome using a large cohort of patients with prospective follow-up.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study included patients with TINU syndrome from a prospective cohort of patients with ATIN from 2007 to 2012. Clinical-pathologic data were collected at biopsy and autoantibodies against modified C-reactive protein (mCRP-Ab) were measured. Serum levels and renal tissue expression of Kreb von den Lunge-6 were also detected. Independent risk factors for poor renal outcome at 12 months and late-onset uveitis were analyzed.

RESULTS

Thirty-one patients (28%) with biopsy-proven ATIN were classified as having TINU syndrome. Of these patients, 18 (58%) developed late-onset uveitis and were misdiagnosed as having drug-induced ATIN at the time of biopsy. An abnormal level of mCRP-Ab was an independent risk factor for late-onset uveitis (odds ratio, 14.7; 95% confidence interval, 3.4 to 64.0). Patients with TINU syndrome and drug-induced ATIN had comparable levels of Kreb von den Lunge-6 in both serum and renal tissues. Ninety-two percent of patients developed stage 3-4 CKD and/or tubular dysfunction by 12 months postbiopsy. Age, serum creatine level, erythrocyte sedimentation rate, and the presence of concomitant thyroid disease or leukocyturia were related to poor renal outcome. Relapse was seen in 36% (11 of 31) of patients and potentiated poor renal outcome.

CONCLUSIONS

The diagnosis of TINU syndrome can be missed in a large fraction of patients with ATIN because uveitis can present well after the onset of tubulointerstitial nephritis. Elevated mCRP-Ab levels may be useful in predicting late-onset uveitis TINU syndrome. Unfortunately, patients with TINU tended to have frequent relapses and most patients had incomplete renal recovery. Long-term follow-up is needed to prevent misdiagnosis and properly manage TINU syndrome.

[Acute renal failure following Chlamydia pneumoniae pneumonia in a child]

Acute renal failure (ARF) following Chlamydia pneumoniae pneumonia is rarely reported in adults. We present an observation in a 10-year-old child, who had C. pneumoniae pneumonia treated with roxithromycin for a period of 10 days, without any other nephrotoxic drug, in particular nonsteroidal anti-inflammatory drugs. At the end of antibiotic treatment, he presented with asthenia, polyuria, polydipsia, increased plasma creatinine, metabolic acidosis, hypokalemia, and markers of tubular damage. The etiological investigations showed positive C. pneumoniae antibodies, increased serum concentrations of C3 and C4 complement, IgA, and IgG. No uveitis was noted. The diagnosis was tubulointerstitial nephropathy after C. pneumoniae pneumonia. C. pneumoniae pneumonia should be considered a differential diagnosis of community-acquired pneumonia, especially in cases of poor response to conventional antibiotic therapy. It may be associated with tubulointerstitial nephropathy and/or rapidly progressive glomerulonephritis whose severity varies in children as in adults. Early and effective treatment of C. pneumoniae infection with macrolide antibiotics usually provides favorable progression of renal function.

Serial renal biopsies in three girls with tubulointerstitial nephritis and uveitis syndrome

Tubulointerstitial nephritis and uveitis (TINU) syndrome is considered to have a good prognosis even without any immunosuppressive therapy, although there is no histological evidence to support this. The objective of this study was to evaluate, retrospectively, serial renal biopsy findings in three girls with TINU syndrome who were treated with prednisolone. At presentation, all patients had significantly elevated urinary beta(2)-microglobulin levels (7583-19,313 microg/l) and high serum creatinine levels (0.93-1.3 mg/dl). The elevated beta(2)-MG and creatinine levels persisted for 1 month, and renal biopsies were performed to establish a definitive diagnosis. The initial biopsy specimens of all patients revealed marked interstitial enlargement consisting of infiltration of lymphocytes; there was also notable tubulitis and infiltration of eosinophils. All patients received prednisolone therapy following the diagnosis. A second renal biopsy was performed 9 months after the first biopsy for two of three patients, and 2 years later for the third patient. The biopsy specimens taken at 9 months still showed histological changes of acute inflammation; in contrast, that taken at 2 years showed a lower degree of acute inflammation, but scar formation was observed in some regions. Based on these results, we conclude that selected TINU syndrome patients require some immunosuppressive therapy.