Tubulointerstitial nephritis and uveitis syndrome following meningitis and systemic lymphadenopathy with persistent Toxoplasma immunoglobulin M: a case report

Antibodies against Toxoplasma gondii positive in serum and aqueous humor to diagnose clinically suspected ocular toxoplasmosis: A case report

INTRODUCTION

Previously, diagnosis of ocular toxoplasmosis is based on clinical symptoms and Toxoplasma serology. Checking serological indicators often cannot reflect the real intraocular situation, and may even mislead clinicians to make wrong judgments.

PATIENT CONCERNS

A 38-year-old male patient visited our ophthalmology clinic with a chief complaint of decreased vision for about 5 days in his right eye.

DIAGNOSIS

Aqueous humor sample analysis found Toxoplasma DNA detectable, and Toxoplasma immunoglobulin G (IgG) and immunoglobulin M (IgM) to be positive. His serum Toxoplasma IgG was also positive (10.04 IU/mL; reference range: 0 to 7.2 IU/mL). Therefore, the final diagnose was ocular toxoplasmosis involving his right eye.

INTERVENTIONS

Oral prednisone 60 mg/day and azithromycin 0.25 g/day were started. Oral antibiotic treatment for toxoplasma was continued for 4 weeks, and prednisone followed by weekly stepwise tapering in steps of 10 mg/day.

OUTCOMES

The BCVA and fundus of right eye remained stable after treatment at follow-up.

CONCLUSIONS

This article reported a case of ocular Toxoplasma gondii infection diagnosis by serum and aqueous humor antibody tests. We provide some additional information on the T gondii infection diagnosis.

Anti-Toxoplasma gondii IgM Long Persistence: What Are the Underlying Mechanisms?

Diagnosis of Toxoplasma gondii acute infection was first attempted by detection of specific IgM antibodies, as for other infectious diseases. However, it was noted that this immunoglobulin declines slowly and may last for months or even years. Apart from the diagnostic problem imposed on clinical management, this phenomenon called our attention due to the underlying phenomena that may be causing it. We performed a systematic comparison of reports studying IgM antibody kinetics, and the data from the papers were used to construct comparative plots and other graph types. It became clear that this phenomenon is quite generalized, and it may also occur in animals. Moreover, this is not a technical issue, although some tests make more evident the prolonged IgM decay than others. We further investigated biological reasons for its occurrence, i.e., infection dynamics (micro-reactivation–encystment, reinfection and reactivation), parasite strain relevance, as well as host innate, natural B cell responses and Ig class-switch problems inflicted by the parasite. The outcomes of these inquiries are presented and discussed herein.

Management of corticosteroid-dependent eosinophilic interstitial nephritis: A case report

INTRODUCTION

Drug-induced acute interstitial nephritis (DI-AIN) is an important cause of acute kidney injury. In renal biopsy specimens, tubulitis with eosinophilic infiltration is suggestive of DI-AIN. Although corticosteroid therapy and discontinuation of the offending drug can improve renal dysfunction in most cases of DI-AIN, some patients experience AIN recurrence, leading to corticosteroid dependency. Corticosteroid-dependent eosinophilic interstitial nephritis presents a difficult dilemma in diagnosis and information regarding optimum management is limited.

PATIENT CONCERNS

A 25-year-old man, who received treatment with carbamazepine, zonisamide, valproate, and lacosamide for temporal lobe epilepsy, showed an increase in serum creatinine level from 0.98 to 1.29 mg/dL over a period of 6 months. Although he exhibited no symptoms, his serum creatinine level continued to increase to 1.74 mg/dL.

DIAGNOSIS

Renal biopsy revealed tubulitis and interstitial inflammatory infiltrates with eosinophils. Immunological and ophthalmological examinations showed no abnormal findings, and thus, his renal dysfunction was presumed to be caused by DI-AIN. Although oral prednisolone (PSL) administration (40 mg/d) and discontinuation of zonisamide immediately improved his renal function, AIN recurred 10 months later. The increase in PSL dose along with discontinuation of valproate and lacosamide improved renal function. However, 10 months later, recurrent AIN with eosinophilic infiltration was confirmed by further biopsy. The patient was therefore diagnosed with corticosteroid-dependent eosinophilic interstitial nephritis.

INTERVENTIONS

To prevent life-threatening epilepsy, carbamazepine could not be discontinued; hence, he was treated with an increased dose of PSL (60 mg/d) and 1500 mg/d of mycophenolate mofetil (MMF).

OUTCOMES

MMF was well tolerated and PSL was successfully tapered to 5 mg/d; renal function stabilized over a 20-month period.

LESSONS

The presence of underdetermined autoimmune processes and difficulties in discontinuing the putative offending drug discontinuation are contributing factors to corticosteroid dependency in patients with eosinophilic interstitial nephritis. MMF may be beneficial in the management of corticosteroid-dependent eosinophilic interstitial nephritis by reducing the adverse effects related to high-dose and long-term corticosteroid use.