Tubulointerstitial nephritis and uveitis syndrome with autoantibody directed to renal tubular cells

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.

RARE COMPLICATION OF COVID -19 DISEASE TINU SYNDROME IN A 11-YEAR-OLD BOY, FEATURES AND MANAGMENT

Tubulointerstitial nephritis and uveitis syndrome (TINU) is a rare disease defined by a combination of different abnormalities, tubulointerstitial nephritis and uveitis. We describe an 11-year-old boy who got sick with the Covid-19 disease with positive outcome and after 2 weeks developed a complication - tubulointerstitial nephritis with pain in the abdominal cavity, loss of appetite, weakness and low-grade fever with further subsequent attachment of anterior uveitis. Laboratory indicators corresponded to renal insufficiency of tubular origin. Ophthalmological examination conducted against the background of redness of both eyes, photophobia, pain in the eyeball area and decreased vision confirmed bilateral uveitis. Analysis showed high levels of La/SS-B, anti-SARS-CoV-2 IgG with confirmed the suspicion of post-covid TINU syndrome. This case showed a good response to steroid therapy with long-term remission of nephritis and less clinical efficacy in the treatment of uveitis. Special attention should be paid to the occurrence of such a rare syndrome at an early stage after recovery from the Covid-19 disease.

Tubulointerstitial nephritis and uveitis (TINU) syndrome and recent Streptococcus infection in a 9-year-old girl

A 9-year-old girl presented to hospital with a 6-week history of non-specific constitutional symptoms and weight loss. She initially underwent extensive medical investigation without diagnosis being achieved. Although raised inflammatory markers and impaired renal function were noted during her initial admission to hospital, it was her subsequent presentation 2 weeks later with sudden-onset bilateral anterior uveitis that prompted a renal biopsy that indicated acute tubulointerstitial nephritis. A diagnosis of tubulointerstitial nephritis and uveitis (TINU) syndrome was made and systemic glucocorticoid treatment initiated to prevent visual loss and preserve renal function. She has subsequently been reviewed in multidisciplinary outpatient clinics and treated with a tapering regimen of immunosuppressive therapy. Her treatment has been complicated by the side effects of glucocorticoids and by persistent relapses in ocular disease and abnormalities on urinalysis. Recent clinical investigations indicate that her uveitis is controlled and that renal function remains well preserved.

TINU-associated Fanconi syndrome: a case report and review of literature

Background

Tubulo-interstitial Nephritis and Uveitis (TINU) syndrome is a rare oculo-renal inflammatory disease. Renal tubular defects are usually found, but full proximal tubular abnormalities have rarely been described.

Case presentation

We report the case of a 55-year old woman, native from Morocco, presenting with bilateral, non-granulomatous, anterior uveitis, mild renal insufficiency, leucocyturia and glycosuria. Further work-up showed hypophosphatemia and hyperphosphaturia, hypouricemia and hyperuricosuria, and hyper aminoaciduria, consistent with Fanconi syndrome. A kidney biopsy was obtained and showed diffuse interstitial infiltrates with tubular necrosis. The patient improved after the initiation of a corticosteroid therapy, with tapering dose.

Conclusions

We reviewed the literature and found nine similar cases. This association mostly occurs in adult woman, without current evidence for an ethnic predilection, unlike previously reported. The renal prognosis seems favorable after corticosteroid therapy, even in case of severe renal injury. Nonetheless mild tubular defects may persist after treatment or spontaneous remission.

The Syndrome of Tubulointerstitial Nephritis With Uveitis (TINU)

The syndrome of tubulointerstitial nephritis and uveitis (TINU) is a multisystemic autoimmune disorder that may occur in response to various environmental triggers, including drugs and microbial pathogens. Evidence exists of HLA antigen-related genetic predisposition to developing TINU. The resulting inflammation affects chiefly the ocular uvea and renal tubules, although other organs may be involved. TINU is uncommon; only about 200 cases are on record since its original description 40 years ago, although it is possible that new ones are no longer being reported. Although its incidence is highest in children and adolescents, all ages may be affected. Renal and ocular inflammation may be clinically severe and persistent, but the prognosis for the majority of patients with TINU is favorable. Owing to its low prevalence, no standard therapeutic protocols have been established, but most reported cases have been treated with corticosteroids or other immunomodulatory agents. TINU has many features in common with sarcoidosis, the main clinical entity from which it must be distinguished. This article begins with an illustrative case vignette, followed by an overview of the syndrome and current theories regarding its pathogenesis.

Long-term Follow-up of Patients with Tubulointerstitial Nephritis and Uveitis (TINU) Syndrome

PURPOSE

To evaluate the response to treatment in patients with tubulointerstitial nephritis and uveitis (TINU) syndrome over a long-term follow-up period.

METHODS

Nine patients with TINU syndrome were retrospectively reviewed. The mean follow-up was 54.8 months (range: 24-133 months).

RESULTS

The mean number of recurrences per year declined from 1.7 in the 1st year to 0.66 in the 2nd year of treatment. The ocular inflammation responded to local corticosteroids in two patients, systemic corticosteroids in two patients, immunosuppressive therapy in four patients, and anti-TNF-α blocking agent in one patient. The therapy could be discontinued in six (67%) patients after a mean treatment period of 29.5 months. In five patients, remission with the recurrence-free period of 12.8 months was achieved.

CONCLUSIONS

TINU syndrome was characterized by limited responsiveness to corticosteroid therapy and less by severe complications. A long-term course of immunosuppressants or biologics was necessary to control the uveitis and led to induction of remission.

A Rare Case of Tubulointerstitial Nephritis and Uveitis Syndrome Treated with a Multi-Specialty Approach

Patient: Female, 23

Final Diagnosis: Tubulointerstitial nephritis and uveitis syndrome

Symptoms: Abdominal pain • eye redness

Medication: —

Clinical Procedure: —

Specialty: Opthalmology

Recurrence of Tubulointerstitial Nephritis Without Uveitis, in a Patient with Previous Tubulointerstitial Nephritis and Uveitis Syndrome After Transplant

We report a case of recurrent tubulointerstitial nephritis without uveitis in a patient with previous tubulointerstitial nephritis and uveitis syndrome after transplant. A 26-year-old male patient who had been diagnosed with tubulointerstitial nephritis and uveitis syndrome at 8 years of age developed end-stage renal failure and subsequently underwent living-donor related renal transplant at 17 years old. The 1st recurrence of tubulointerstitial nephritis and uveitis occurred 36 months after transplant, which was treated with increased immunosuppressive drugs. Graft function worsened again to estimated glomerular filtration rate of 25 mL/min/1.73 m² at 76 months after transplant. Transplant ultrasonography was unremarkable. Virology tests (including cytomegalovirus, BK virus, and Epstein-Barr virus tests) were all negative, with negative donor-specific antibodies. Urine protein creatinine ratio was unremarkable. A biopsy showed chronic allograft rejection and graft sclerosis, and immunosuppressive medications were subsequently decreased. The patient's renal function continued to decline over the next 3 months, with estimated glomerular filtration rate showing 18 mL/min/1.73 m², prompting a further renal biopsy that showed granulomatous interstitial nephritis and moderate interstitial fibrosis. This was consistent with a further relapse of tubulointerstitial nephritis but without uveitis. His renal function improved over the next few months after tacrolimus was reintroduced.

Autoantibodies Targeting a Collecting Duct-Specific Water Channel in Tubulointerstitial Nephritis

Tubulointerstitial nephritis is a common cause of kidney failure and may have diverse etiologies. This form of nephritis is sometimes associated with autoimmune disease, but the role of autoimmune mechanisms in disease development is not well understood. Here, we present the cases of three patients with autoimmune polyendocrine syndrome type 1 who developed tubulointerstitial nephritis and ESRD in association with autoantibodies against kidney collecting duct cells. One of the patients developed autoantibodies targeting the collecting duct-specific water channel aquaporin 2, whereas autoantibodies of the two other patients reacted against the HOXB7 or NFAT5 transcription factors, which regulate the aquaporin 2 promoter. Our findings suggest that tubulointerstitial nephritis developed in these patients as a result of an autoimmune insult on the kidney collecting duct cells.

HLA-DR, DQ class II DNA typing in pediatric panuveitis and tubulointerstitial nephritis and uveitis

PURPOSE

To describe chorioretinal lesions in pediatric uveitis that are associated strongly with the HLA-DR, DQ class II type associated with tubulointerstitial nephritis and uveitis (TINU).

DESIGN

Retrospective, observational case series.

METHODS

SETTING

University-based clinic.

PATIENT POPULATION

Fifteen consecutive patients with onset of bilateral panuveitis at less than 16 years of age who were seen between September 2004 and October 2012 and 6 pediatric patients with confirmed TINU.

OBSERVATION PROCEDURE

HLA-DR, DQ class II DNA typing.

MAIN OUTCOME MEASURE

Detection of the HLA-DRB1*01 and HLA-DQB1*05 risk alleles for TINU.

RESULTS

Fourteen (93%) of the 15 patients with otherwise unexplained pediatric panuveitis typed HLA-DRB1*01-HLA-DQB1*05. Eleven (73.3%) of 15 patients had bilateral sharply demarcated, usually inferior, 200- to 300-μm spots of chorioretinal atrophy, and 4 (27.7%) of 15 patients had bilateral clusters of 500- to 750-μm poorly defined orange choroidal lesions without overlying atrophy of the retinal pigment epithelium. None had interstitial nephritis. Four of the 6 definite TINU cases had class II typing and TINU risk alleles; all 6 had bilateral panuveitis. The frequency of risk alleles was statistically higher in those with pediatric panuveitis than in the North American population and in nonpanuveitis pediatric uveitis patients assumed to have the North American HLA distribution (P < .0001, Fischer exact test). Positive likelihood ratios were 9.92 to 5.18, depending on assumptions regarding pretest probability of disease.

CONCLUSIONS

Recognition of characteristic chorioretinal lesions in otherwise unexplained pediatric panuveitis, supported by selective HLA class II DNA typing, is useful in narrowing diagnostic possibilities and directing further evaluations. Panuveitis is underappreciated as a manifestation of TINU.

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.

HLA associations with tubulointerstitial nephritis with or without uveitis in Finnish pediatric population: a nation-wide study

The human leukocyte antigen (HLA) genotype has been shown to associate with tubulointerstitial nephritis (TIN) and tubulointerstitial nephritis with uveitis syndrome (TINU). The association of HLA genes with TIN was examined in this nation-wide study. HLA genotyping was performed in 31 pediatric patients with biopsy-proven TIN. All patients were examined by an ophthalmologist to diagnose possible uveitis. Class II HLA genotypes of TIN patients were compared with the Finnish reference population. We found a significant association between the HLA alleles DQA1*04:01 [risk ratio (RR) 5.0, 95% confidence interval (CI) 2.0-11.2], DQB1*04:02 (RR 2.7, 95% CI 1.4-5.3), and DRB1*08 (RR 3.8, 95% CI 1.5-8.4) and TIN. Uveitis was found in 20/31 (64.5%) patients. HLA genotyping of the TINU patients showed additional risk HLA alleles: DQA1*01:04 (RR 6.1, 95% CI 1.5-17.8), and DRB1*14 (RR 8.2, 95% CI 2.2-22.1). The alleles DQA1*01:04 (RR 8.8, 95% CI 2.2-26.5), DQA1*04:01 (RR 3.2, 95% CI 1.2-7.3), and DRB1*14 (RR 12.0, 95% CI 3.2-33.0) were more frequent in patients with TIN and chronic uveitis than in reference population. The HLA class II haplotype DQA1*04:01/DQB1:04:02/DRB1*08 was the most common combination in our study population (58.1%). None of the patients had haplotype DQA1*04:01/DQB1*06:02/DRB1*15, which is common in Finland. HLA genotype did not predict the renal outcome. We found a strong association between certain HLA genotypes both in TIN and TINU patients. The TIN/TINU-associated HLA alleles appear to vary depending on study population.

Recurrent tubulointerstitial nephritis and uveitis syndrome in a renal transplant recipient

We report for the time a patient with recurrence of tubulointerstitial nephritis and uveitis (TINU) following renal transplantation. Our patient was diagnosed at the age of 8 years and, despite treatment with systemic steroids, developed established renal failure. At the age of 17 years, he underwent a live-related donor renal transplant. Immunosuppression included tacrolimus, mycophenolate mofetil and prednisolone. Having had normal renal function for 3 years after transplantation, he developed uveitis and decline in the graft function. A biopsy of the allograft demonstrated recurrent granulomatous interstitial nephritis. The recurrence of TINU following transplantation suggests a role for circulating autoantibodies in the disease pathology.

Modified C-reactive protein might be a target autoantigen of TINU syndrome

BACKGROUND AND OBJECTIVES

The cross-reactive antigen(s) of tubulointerstitial nephritis and uveitis (TINU) syndrome from renal tubulointerstitia and ocular tissue remain unidentified. The authors' recent study demonstrated that the presence of serum IgG autoantibodies against modified C-reactive protein (mCRP) was closely associated with the intensity of tubulointerstitial lesions in lupus nephritis. The study presented here investigates the possible role of IgG autoantibodies against mCRP in patients with TINU syndrome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

mCRP autoantibodies were screened by ELISA with purified human C-reactive protein in 9 patients with TINU syndrome, 11 with drug-associated acute interstitial nephritis, 20 with IgA nephropathy, 19 with minimal change disease, 20 with ANCA-associated vasculitis, 6 with Sjogren's syndrome, and 12 with amyloidosis. mCRP expression was analyzed by immunohistochemistry in renal biopsy specimens from the 9 patients with TINU syndrome and 40 from disease controls. Frozen normal human kidney and iris were used to demonstrate co-localization of human IgG and mCRP from patients with TINU syndrome with laser scanning confocal microscopy.

RESULTS

The mCRP autoantibodies were detected in all nine patients with TINU syndrome, significantly higher than that of those with disease controls (P < 0.05). The renal histologic score of mCRP in TINU syndrome was significantly higher than that in disease controls (P < 0.05). The staining of mCRP and human IgG were co-localized in renal and ocular tissues.

CONCLUSIONS

It is concluded that mCRP might be a target autoantigen in TINU syndrome.

Tubulointerstitial nephritis and uveitis (TINU) syndrome: a case report and review of the literature

PURPOSE

We aim to describe the first case of tubulointerstitial nephritis and uveitis (TINU) syndrome reported in Scandinavia and to underline the importance of the syndrome, which should be better known among ophthalmologists.

METHODS

We report an 11-year-old boy who was admitted to hospital because of general fatigue and weight loss. Blood tests showed renal insufficiency and a renal biopsy revealed acute tubulointerstitial nephritis. One week after admission the patient developed transitory blurred vision and flickering shadows in the left eye. Slit-lamp examination revealed bilateral anterior non-granulomatous uveitis and TINU syndrome was diagnosed.

RESULTS

Because of renal insufficiency the patient was treated with systemic prednisone 50 mg/day for 3 weeks. Evolution was favourable, and prednisone was tapered over 10 weeks. Uveitis was treated with topical steroid with good effect. The only complication after 18 months of follow-up was transitory cushingoid aspect.

CONCLUSIONS

Tubulointerstitial nephritis and uveitis syndrome is a rare syndrome that is probably underdiagnosed in clinical practice. Co-operation between ophthalmologists and nephrologists/paediatricians is crucial for early diagnosis and instigation of treatment. Uveitis may occur before tubulointerstitial nephritis or the renal symptoms may be so mild that the patient is unaware of them. Therefore, ophthalmologists play an important role in the initial discovery of patients with TINU syndrome. Tubulointerstitial nephritis tends to be self-limiting, whereas uveitis tends to relapse and recurrences tend to be more severe than the initial uveitis. Therefore, the patient must be ophthalmologically monitored very carefully.

Elevation of serum Krebs von den Lunge-6 levels in patients with tubulointerstitial nephritis and uveitis syndrome

BACKGROUND

Tubulointerstitial nephritis and uveitis (TINU) syndrome is characterized by a combination of idiopathic acute tubulointerstitial nephritis and uveitis. Krebs von den Lunge-6 (KL-6) is a human glycoprotein secreted by type II alveolar cells in the lung, and its serum levels increase in patients with pneumonia of various causes, as well as ocular sarcoidosis. The aim of the present study is to quantify serum KL-6 levels in patients with TINU syndrome, which has no pulmonary and sarcoid lesions, and elucidate the usefulness of KL-6 for the diagnosis and follow-up of this syndrome.

METHODS

Serum and urinary samples were obtained from 17 patients with TINU syndrome and 36 age-matched patients with uveitis from other causes. Sarcoidosis was eliminated because serum KL-6 levels increased during their lung lesion. Serum KL-6 level was determined by using a human KL-6 electrochemiluminescence immunoassay. Formalin-fixed paraffin-embedded renal tissue sections were incubated with anti-KL-6 monoclonal antibody, then examined immunohistochemically.

RESULTS

Mean serum KL-6 levels for patients with TINU syndrome and those with uveitis from other causes were 363.35 +/- 51.06 and 213.19 +/- 10.28 U/mL, respectively (P < 0.001). Urinary beta(2)-microglobulin levels of patients with TINU syndrome and uveitis from other causes were 4.06 +/- 1.31 and 0.16 +/- 0.20 mg/L, respectively (P < 0.001). All patients with TINU syndrome showed a simultaneous decrease in serum KL-6 and urinary beta(2)-microglobulin levels after the beginning of treatment. Strong immunoreactivity for KL-6 was observed in renal distal tubules in biopsy tissue of patients with TINU syndrome.

CONCLUSION

We show a significant increase in serum KL-6 levels in patients with TINU syndrome, whereas levels were normal in patients with other causes of uveitis without nephritis. Renal distal tubules stained strongly with anti-KL-6 antibody, suggesting that high KL-6 levels may reflect the renal lesion of TINU syndrome. Serum KL-6 may be a potential laboratory parameter for the diagnosis and follow-up of patients with TINU syndrome that could complement urinary beta(2)-microglobulin measurements.

Tubulointerstitial nephritis and uveitis syndrome: use of gallium scintigraphy in its diagnosis and treatment

Prompt diagnosis and treatment with corticosteroids of the tubulointerstitial nephritis with uveitis (TINU) syndrome may assist in the preservation of renal function. We present a case illustrating the characteristic clinical features of this syndrome. Gallium scintigraphy assisted in the diagnosis and management of this case, which was complicated by relapsing pyelonephritis.

A case of tubulointerstitial nephritis and uveitis syndrome with severe immunologic dysregulation

Idiopathic tubulointerstitial nephritis and uveitis (TINU) syndrome is an uncommon condition, characterized by acute tubulointerstitial nephritis (TIN) with a favorable course and uveitis with a chronic relapsing course. The pathogenesis remains unclear, but a lymphocyte-mediated immune mechanism has been suggested. A 9-year-old boy was evaluated for fatigue and 2 kg of weight loss. Renal glucosuria, elevated urine beta(2)-microglobulin (MG), progressive renal dysfunction, polyclonal hypergammaglobulinemia, various autoantibodies and abnormal lymphocyte phenotypes were found. A renal biopsy revealed acute TIN. After 2 months of treatment with prednisolone, renal function and polyclonal hypergammaglobulinemia were normalized. While tapering prednisolone, anterior uveitis developed, which was improved with topical steroid. But abnormal lymphocyte phenotypes and autoantibodies persisted on low-dose prednisolone. Uveitis became aggravated, and urine beta(2)-MG increased again. The second renal biopsy (7 months later) was normal except for minimal focal interstitial fibrosis. Uveitis was not responsive to systemic steroids, but improved with additional cyclosporin. Abnormal lymphocyte phenotypes improved, and most autoantibodies disappeared. We report a rare case of idiopathic TINU syndrome with severe immunologic dysregulation, which correlated with the clinicopathological and biochemical parameters. The information about lymphocyte phenotypes and autoantibodies may provide more insight into the pathophysiology and the clinical course of uveitis in this rare disorder.

Adult onset tubulointerstitial nephritis and uveitis syndrome

A Turkish woman aged 44 years who presented with a 1 month history of abdominal pain, fatigue and weight loss of 10 kg was diagnosed as having acute tubulointerstitial nephritis. Opthalmological evaluation revealed unilateral uveitis and contralateral chorioretinal scarring. X-ray films of the pelvis revealed unilateral sacroileitis. An elevated erythrocyte sedimentation rate, C-reactive protein, tubular proteinuria and renal glucosuria returned to normal 2 weeks after treatment was started. It is important to be aware of tubulointerstitial nephritis and uveitis syndrome in order to achieve a quick diagnosis in patients with renal impairment and tubular dysfunction with minor symptoms so that appropriate management can be started early.

Clinical features in tubulointerstitial nephritis and uveitis (TINU) syndrome

PURPOSE

To analyze clinical features of the tubulointerstitial nephritis and uveitis (TINU) syndrome in Japan, especially exacerbations or recurrences of uveitis.

DESIGN

Retrospective observational study.

METHODS

We reviewed the clinical features in 12 patients with TINU syndrome diagnosed by renal biopsy, who were evaluated and treated at the Department of Ophthalmology, Hokkaido University Hospital. Visual acuity was measured using decimal visual acuity.

RESULTS

Patient age ranged from 10 to 33 years (mean 21 years), and females accounted for 83% of the cases. Both eyes were affected in 11 patients (92%). All 12 patients initially experienced ocular symptoms, with hyperemia being the chief complaint. We diagnosed patients as having uveitis and conducted blood tests and urinalysis. Urinalysis did show characteristic findings, most notably glucosuria, increased beta2 microglobulin that were > or = 10 times that of normal levels, and increased N-acetylglucosaminidose levels in a high percentage of patients. Recurrent or exacerbating uveitis was seen in six patients (50%). In exacerbated or recurrent uveitis, inflammation was more severe (> or = 3+ cells of the anterior eye segment). The ocular inflammation generally responded well to treatment with oral corticosteroids, and the number of recurrences was lower at corticosteroid doses of > or = prednisolone 40 mg.

CONCLUSIONS

Ophthalmologists play an important role in the initial discovery of patients with TINU syndrome. Because inflammation was more severe in exacerbated or recurrent uveitis, in instances where uveitis is refractory to local therapy, oral corticosteroids should be considered as early as possible.

The role of mast cells in acute tubulo-interstitial nephritis with uveitis

We describe the clinicopathological characteristics of two patients with acute tubulo-interstitial nephritis with uveitis (TINU) with mast cells infiltrating the interstitium. The pathogenesis of TINU remains unknown, but a T-cell-mediated immune response was suggested to be involved. Recent studies have shown that infiltrating mast cells are closely associated with the development of renal interstitial fibrosis in glomerulonephritis. To address the role of mast cells in the renal interstitial injury in TINU, immunohistochemical studies were performed in renal biopsy sections using anti-human mast cell tryptase antibody specific for mast cells. In addition, we tried to detect CD68-positive macrophages to compare with the localisation of mast cells within the renal interstitium. Mast cells and macrophages could be detected in renal interstitial lesions of both patients. Massive infiltration of macrophages into interstitial lesions was observed, whereas mast cells were detected in a sporadic rather than a clustered manner, and associated with fibrotic lesions. Repeat renal biopsy findings suggested the involvement of these cells in the renal interstitial injury because the number of infiltrating mast cells and macrophages in the interstitium decreased with the improvements in clinical symptoms and pathological lesions.

CONCLUSION

The present study showed that mast cells might play an important role in the development of renal interstitial injury in tubulo-interstitial nephritis with uveitis.