Authors: Pedro Mesquita , Marta Braga Martins , Juliana Andrade , Rita Goncalves Pinto , Gonçalo Torrinha , Céu Rodrigues , Vânia Gomes

Abstract

Background: Lupus podocytopathy (LP) is a rare histopathological diagnosis of renal biopsies performed in the context of systemic lupus erythematosus (SLE) with renal involvement. Steroid-induced psychosis is a well-documented phenomenon. 

Case Presentation: A 55-year-old woman, diagnosed with SLE, went to the emergency department due to asthenia, inflammatory polyarthritis, and decreased urinary output. The blood panel showed hypoalbuminemia and acute kidney injury and the protein/creatinine ratio was elevated. She was admitted with a diagnosis of probable lupus nephritis (LN) and pulses of methylprednisolone were started. During hospitalization, an amplified study was conducted. A 24-hour urine sample showed proteinuria in the nephrotic range. Renal biopsy was conducted and the results showed aspects suggestive of class II lupus nephropathy and the suspicion of LP was therefore high. Despite favorable evolution with high-dose corticosteroid oral therapy, the patient began to experience behavioral changes with delusional and persecutory thoughts, compatible with psychosis, which led to the introduction of tacrolimus and the rapid reduction in steroid doses. During follow-up consultation, the diagnosis of podocytopathy was confirmed by electron microscopic evaluation, with a diffuse fusion of the podocyte pedicels and without subepithelial deposits or organized structures.

Conclusion: LP is a rare histopathological diagnosis and should be suspected in cases of LN with nephrotic proteinuria. Kidney biopsy and electron microscopy are essential in confirming the diagnosis. It is mandatory to recognize and manage steroid induced psychosis during high-dose corticosteroid therapy. The use of tacrolimus is an important alternative treatment option in such cases.

Keywords: Podocytopathy, systemic lupus erythematosus, tacrolimus, internal medicine.