Dengue Virus Infection as a Trigger for Collapsing Glomerulopathy in a Patient with an APOL1 High-Risk Genotype

Introduction: Collapsing Glomerulopathy (CG) is a severe kidney disease with a fast progression to chronic kidney disease requiring renal replacement therapy (CKD-KRT). We report the first case of CG associated with Dengue (DENV) in a patient with APOL1 high-risk genotype (APOL1-HRG). Case Description: A 41-year-old black female, previously diagnosed with sickle cell anemia, hypertension, and CKD stage 3A was admitted with a 6-day history of fever, headache, nausea, and oliguria. An NS1 antigen-test for DENV resulted positive. On physical examination, the patient had lower limbs edema and hypertension. She was on use of hydroxyurea, enalapril and folic acid. Laboratory tests showed Hb: 7.8g/dL, platelets: 65,000/mm3, DHL: 1442U/L, AST: 609U/L, ALT: 350U/L. albumin: 2.5g/dL, Ur: 83mg/dl, Cr: 6.7mg/dL, mild metabolic acidosis and no electrolyte disturbances. Urinalysis revealed hematuria and 24h-proteinuria: 50g. A kidney biopsy revealed at light microscopy 6 out of 17 globally sclerotic glomeruli, global collapse of the capillary loop associated with podocyte hyperplasia and hypertrophy. Interstitial fibrosis / tubular atrophy quantified in 30% of the compartment. Immunofluorescence stained for C3 2+/3+, with a granular pattern and global and focal distribution (trapping). These findings corroborate the diagnosis of Collapsing Glomerulopathy. She harbors an APOL1-HRG (G1/G1). The patient started on hemodialysis and has been treated with pulse of methylprednisolone 500 mg for 3 days, followed by prednisone 80 mg and mycophenolate 2 g/day. One month after treatment start, the patient improved renal function, and was discharged from hospital with an eGFR 20ml/min/1.73m2 Discussion: Viral infections are frequent triggers for GC in patients with APOL1-HRG. In tropical countries, arboviruses such as DENV, Zika and Chikungunya should also be investigated in patients with GC, especially if they carry APOL1-HRG.