Granulomatous Interstitial Nephropathy : When the Kidney Spills the Bean

Introduction: Sarcoidosis is a rare granulomatosis. The absence of well-defined criteria for definition and the existence of differential diagnosis makes the positive diagnosis difficult. Method(s): We report a case of sarcoidosis that illustrates the difficulty of this diagnosis in the presence of atypical clinical manifestations and a strong suspicion of tuberculosis. Ultimately, renal histology allowed the positive diagnosis and the response to corticosteroids confirmed it retrospectively. Result(s): Our patient was a 66 years-old female with a history of hypertension who presented with a sensory and motor polyneuropathy a couple of months after a mild COVID-19 pneumonia, hospitalized for exploration of a worsening renal function due to a tubulointerstitial neuropathy (creatinine upon admission at 250 micromol/l, eGFR = 16 ml/min/1,73m2 -MDRD). Kidney biopsy revealed an interstitial infiltrate of monocytes and fibrosis alongside non-necrotic and giant-cell epithelioid interstitial granulomas. Extra-renal signs consisted of the above-mentioned neuropathy, bilateral mediastinal adenopathies with no signs of a pulmonary disease at the bodyscan, a hepatomegaly, splenomegaly, a pleural and pericardial effusion of low abundance, and a peritoneal thickening. Bronchoscopy and bronchoalveolar washing found no evidence for malignancies and screening for mycobacterial infections by polymerase chain reaction was negative. No granulomas were found at the hepatic biopsy. Digestive tract endoscopy and biopsies showed no abnormalities. During hospitalization, the patient presented an episode of acute polyradiculonevritis confirmed by cerebral-spine fluid study and nerve conduction study results. Our patient received intraveinous immunoglobulins (IgIV) with a favorable outcome but relapsed one month later, showing signs of respiratory failure. Upon the second relapse of the chronic polyradiculonevritis and based on the absence of bacteriological and histological evidence for a mycobacterial infection and the results or the renal biopsy, the patient received high-dose corticosteroids alongside a second course of IgIV. The neuropathy regressed totally within a month with a decrease of creatinine level to 140 micromol/l (eGFR = 35ml/min/1,73m2) alongside the polyserositis and organomegaly. The final diagnosis was that of a sarcoidosis with pulmonary and renal involvement. Although the neuropathy could be considered a manifestation of sarcoidosis, its origin was intricated as post-viral original could not be formally excluded. Conclusion(s): The etiological diagnosis for granulomatous interstitial nephropathies can be challenging due to similar clinical presentations and the need to start specific treatments especially in the presence of life-threatening situations and the absence of clear criteria defining sarcoidosis further enhances the level of difficulty. No conflict of interestCopyright © 2023

Covid-19 et transplantation rénale

Déclaration de liens d’intérêts: Les auteurs déclarent ne pas avoir de liens d’intérêts.

SARS CoV2 infection complicating cryoglobulinemic vasculitis with renal involvement

BACKGROUND AND AIMS: Cryoglobulinaemic vasculitis (CV) leading to clinically apparent skin lesions, and in some cases also to internal organ involvement such as renal involvement. The SARS Cov2 infection in this field is very serious and in the case of our patient the outcome was fatal. The aim of this work is to highlight the particularities of CV in this case CASE PRESENTATION: We report a case of a 62-year-old woman followed since 2014 for CV type 1 IgG Lambda revealed by vascular purpura and nasal septal perforation. the etiological assessment was negative. Hepatitis C virus serology was negative. A corticosteroid therapy at a dose of 1 mg/kg/day was started with partial improvement. Then the cyclophosphamide at a dose of 150 mg/d was added with a fairly good clinical result but stopped for hemorrhagic cystitis. Chlorominophene was started at a dose of 6 mg/d and then reduced to 4 mg/d for leuconeutropenia but the peripheral arterial manifestations (acrocyanosis of the limbs and ears) were not treated. The evolution was marked by the appearance of renal failure (creatinine 482.33 umol/l) associated with proteinuria at 1.32 g/24h. An outbreak of cryoglobulinemia was suspected. Plasma exchange was discussed as a therapeutic alternative and the patient was scheduled for a renal biopsy. However, the patient became febrile with the appearance of a dry cough and the presence of a biological inflammatory syndrome (CRP at 72). A SARS-CoV-2 PCR was completed which was positive. Therefore, she was put on antibiotic therapy (Azythromycin and Cefotaxime) associated with vitamin therapy and anticoagulant treatment. The patient was stable in terms of respiration and hemodynema, but her renal function worsened and progressed well under hydration. In addition, she presented with a slippage syndrome and she was died CONCLUSION: The natural history of CV is not predictable and strongly depends on concomitant diseases and complications and response to treatment. The SARS Cov2 infection can complicate its evolution. There is no association has been described between them to our knowledge.