Elderly man with metabolic syndrome and recent hernia repair presents 2 weeks post-op with nausea, emesis and acute kidney injury (peak creatinine 4 mg/dl). He denies any recent nephrotoxic exposures.
No known kidney disease, no hematological disorders, no malignancies.
Otherwise well appearing man, slightly elevated blood pressure, with mild abdominal obesity
Serum Alb 2.5 mg/dl
Serum protein-electrophoresis (SPEP) with hypogammaglobulinemia, and on repeat a few months later with trace IgG kappa monoclonal.
Normal complements, serologies negative.
Urine protein to creatinine ratio of 6.2 g/g.
Urine protein-electrophoresis (UPEP) with trace oligoclonal bands of IGG kappa.
Urine analysis notable for 4+ protein, 20-25 red blood cells per high power field with some acanthocytes, 15-20 white blood cells, few hyaline and moderate mixed cellular casts.