U # yr old woman with Serum Cr 202 Urine Pr/Cr 338 mg/mmol,elevated LFTs Weight loss No hematuria SPEP-polyclonal gammopathy (L) Native kidney biopsy

63 year old lady with Creatinine 153 and 2+ proteinuria but no hematuria In February 2006 progressing to 249 and 4+ respectively over 6 weeks. 2-3 years ago admitted to local hospital with "bowel infection", 18 months ago found to have elevated liver enzymes mainly AlkP. Work up negative waiting for liver biopsy. Four days before clinic visit developed superficial thrombophlebitis of the leg. Complains of poor appetite, fatigue and weight loss lbs over 3 years. Has H/O severe PVD requiring carotid endarterectomy and fem-pop by pass, HTN and hyperlipidemia. U

IF IgG-strong background,no specific staining IgA- negative,casts only IgM- mild wispy to granular staining C3- mild to strong vascular pole;moderate to strong in one sclerotic lumen C1q-minimal vascular pole and intimal fibrosis,probably nonspecific background Kappa-negative,mild background Lambda-negative,mild background Fibrin- moderate interstitial staining Albumin- moderate to strong background

comment There is no definite evidence of primary glomerular disease by morphology.the histology is equivocal,but in the context of severe proteinuria,there may be very focal segmental sclerosis secondary to the severe vascular disease.this dose not change the initial interpretation that there is interstitial nephritis,and the presence of eosinophilia and plasma cells indicate there is an active immunologic process going on.

Diagnosis: Renal Biopsy: - Active interstitial nephritis. - Severe arteriosclerotic vasculopathy of small arteries. A)Diffuse glomerulosclerosis,probably on the basis of vascular disease B)Parenchymal scarring and atrophy - Possible lesions of focal segmental glomerulosclerosis,probably secondary