ESPN 54th Annual Meeting

ESPN 2022


 
SARS-CoV-2 Associated Acute Interstitial Nephritis in an Adolescent
KAROLIS AZUKAITIS 1 JUSTINAS BESUSPARIS 2 ARVYDAS LAURINAVICIUS 2 AUGUSTINA JANKAUSKIENE 1

1- CLINIC OF PEDIATRICS, INSTITUTE OF CLINICAL MEDICINE, FACULTY OF MEDICINE, VILNIUS UNIVERSITY, VILNIUS, LITHUANIA
2- INSTITUTE OF BIOMEDICAL SCIENCES, FACULTY OF MEDICINE, VILNIUS UNIVERSITY, VILNIUS, LITHUANIA
 
Introduction:

Acute interstitial nephritis (AIN) has been recently recognized as one of the infrequent kidney involvement phenotypes among adult patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. Although SARS-CoV-2 associated intrinsic kidney disease has been still scarcely reported in children, at the time of this case report only one case of AIN has been published.

Material and methods:

Case report of a 12 year old boy with AIN. Immunohistochemistry (IHC) for Anti-SARS-CoV-2 spike glycoprotein antibody (abcam: ab272504) and electron microscopy (EM) was performed.

Results:

The patient presented with fatigue, anorexia and polydipsia following a real-time polymerase chain reaction confirmed SARS-CoV-2 infection 6 weeks ago. Initial work-up revealed estimated glomerular filtration rate (eGFR) of 23 ml/min/1.73 m2, high erythrocyte-sedimentation rate (120 mm/h), anemia (hemoglobin 9.8 g/dL), thrombocytosis (517 x 109) and increased C-reactive protein (49.6 mg/L). Urine tests showed glucosuria, low-molecular weight proteinuria and microhematuria with hyaline and granular casts on microscopy. Antibodies against SARS-CoV-2 S protein receptor binding domain confirmed prior infection with high titres (453 BAU/ml). Kidney biopsy showed diffuse active interstitial nephritis with negative immunofluorescence and positive IHC for SARS-CoV-2 in interstitial inflammatory infiltrate and EM revealed SARS-CoV-2-like viral particles. Kidney function continued to deteriorate despite several days of watch and wait period (eGFR nadir 19.8 ml/min/1.73 m2) and thus treatment with methylprednisolone pulse-dose therapy (1000 mg thrice) was initiated. This was followed by oral methylprednisolone 48 mg once daily which led to complete normalization of kidney function within 3 weeks.

Conclusions:

Our case adds to the emerging evidence of SARS-CoV-2 as a potential etiological agent of AIN in children. In the light of evolving virus spread among children and potential asymptomatic course, epidemiological history, serologic testing and SARS-CoV-2 detection in biopsy should be added to the work-up of children with AIN of unknown etiology.