epstein  barr virus ( ebv ) commonly infects young adults and manifestations range from a benign course to infectious mononucleosis ( i m ) . i m is a clinical syndrome of self - limited illness with a fever , pharyngitis and lymphadenopathy . a 22-year - old male presented to his primary care physician with 1 week of fatigue , fever , sore throat , nausea and vomiting . physical examination revealed tonsillitis . a rapid streptococcal throat test was negative and a diagnosis of i m was confirmed with a positive igm antibody against the ebv capsid antigen . initial conservative management failed and tonsillitis worsened requiring two emergency room visits for dehydration . a urine analysis revealed normal microscopy but was significant for a random urine protein of 620 mg / dl , protein - to - creatinine ratio of 5.6 and predicted 24-h urine protein of 10.3 g. subsequently , he was hospitalized with worsening tonsillitis , acute renal failure and proteinuria . physical exam revealed significant tonsillitis , periorbital swelling , bilateral lower extremity pitting edema and tachycardia . a total cholesterol and low - density lipoprotein cholesterol were elevated at 316 mg / dl ( 8.1 mmol / l ) and 222 mg / dl ( 5.7 mmol / l ) , respectively . subsequent blood evaluation for anti - deoxyribonuclease - b and anti - streptolysin titers were negative . further evaluation included a negative anti - nuclear antibody and anti - neutrophil cytoplasmic antibodies screen , cryoglobulin and cryofibrinogen , normal c3 complement and mildly elevated c4 complement , 53 u / ml ( normal : 1545 u / ml ) . cold agglutinins and anti - ebv - viral - capsid - antigen igm were positive . igg antibodies against the anti - ebv - viral - capsid - antigen were negative suggesting acute ebv infection . tissue immunofluorescence studies ( iga , igg , igm , c1q , c3 , albumin , fibrinogen , kappa and lambda light chains ) were negative . electron microscopy revealed extensive effacement ( > 90% ) of the foot processes of the visceral epithelial cells , consistent with minimal change disease ( figure 2 ) . electron microscopy showing extensive effacement of podocyte foot processes ( black arrow ) ( e , endothelial cells , m , mesangial cells , arrows point to foot process effacement ) . the patient was commenced on dexamethasone 10 mg on day one followed by a tapering dose of methylprednisolone beginning at 24 mg per day , and tapered by 4 mg daily to zero ( starting at 16 mg / day ) for persistent proteinuria and worsening tonsillitis . three days after treatment was completed , he had marked improvement of sore throat and complete resolution of proteinuria . i m is usually a clinical syndrome characterized by a self - limiting illness with fever , pharyngitis and lymphadenopathy . sub - clinical renal involvement is not uncommon ; 16% of patients with i m have abnormalities in urinary sediment . this usually manifests as acute renal failure , rhabdomyolysis or immune complex glomerulonephritis and rarely minimal change disease , membranous nephropathy and cholemic nephrosis [ 2 , 3 ] . a review of 27 cases of acute renal failure in heterophile positive i m by meyer et al . , showed that 18% had rhabdomyolysis and myoglobinuria and one patient had minimal change disease . only 13 of the 27 patients underwent kidney biopsies , 10 of whom had interstitial nephritis . another two had immune - complex glomerulonephritis [ 4 , 5 ] . in 1996 , proteinuria resolved after resolution of the viral infection . a renal biopsy was not done . two cases of ebv - associated renal failure were reported in 2000 and 2002 associated with interstitial nephritis and one of these also had minimal change disease [ 7 , 8 ] . t lymphocytes may be activated having recognized ebv antigens in kidney tissue or there may be direct renal injury due to ebv . mayer s case review demonstrated a predominance of cases with cytotoxic t cells in the interstitium . however , there was also evidence of ebv dna detected by polymerase chain reaction ( pcr ) in renal tissue in patients with interstitial nephritis favoring direct virally mediated renal toxicity . ebv receptors ( cd21 ) were detected in proximal tubule cells and were up - regulated in the ebv - infected tissues . in 2002 , okada et al .   reported a case of a patient with chronic active ebv infection who developed both acute tubulointerstitial nephritis and minimal change disease . ebv dna was detected by pcr in some infiltrating lymphocytes but not in the tubular epithelial cells . it was proposed that ebv - infected t - cells activated other cells ( educated t cells ) , which infiltrated into the interstitium and secreted cytokines and promoted tubular epithelial atypia and minimal change disease . in our case , the kidney biopsy tissue was negative for ebv mrna by in situ hybridization and there were no interstitial infiltrates . contrary to current literature where there is not strong evidence for steroid use in i m , our patient s nephrotic syndrome rapidly and completely responded to steroid therapy . in conclusion , minimal change nephropathy is a rarely reported renal complication of i m with few cases reported and is exquisitely steroid responsive . i m should therefore be considered in all cases of minimal change disease preceded by viral prodromal illness .
acute infection with epstein  barr virus ( ebv ) causes fever , fatigue and pharyngitis . 
 renal involvement in systemic ebv infections typically manifests as acute tubular necrosis or tubulointerstitial nephritis . 
 rarely , ebv infection causes nephrotic syndrome due to minimal change disease . a 22-year - old male with infectious mononucleosis ( i m ) presented with nephrotic syndrome . 
 renal biopsy showed minimal change disease with diffuse foot process effacement of the podocytes . 
 treatment with methylprednisone led to rapid and complete clinical remission . 
 minimal change nephropathy is a very rare manifestation of ebv infection and should be considered in patients with i m and proteinuria .