APOL1-Associated Collapsing Focal Segmental Glomerulosclerosis in a Patient With Stimulator of Interferon Genes (STING)-Associated Vasculopathy With Onset in Infancy (SAVI).

Apolipoprotein L1 (APOL1) risk variants G1 and G2 are known to result in risk for kidney disease in patients of African ancestry. APOL1-associated nephropathy typically occurs in association with certain environmental factors or systemic diseases. As such, there has been increasing evidence of the role of interferon (IFN) pathways in the pathogenesis of APOL1-associated collapsing glomerulopathy in patients with human immunodeficiency virus (HIV) infection and systemic lupus erythematosus, 2 conditions that are associated with high IFN levels. Collapsing glomerulopathy has also been described in patients receiving exogenous IFN therapy administered for various medical conditions. We describe a patient with a genetic condition that results in an increased IFN state, stimulator of IFN genes (STING)-associated vasculopathy with onset in infancy (SAVI), who developed collapsing glomerulopathy during a flare of his disease. The patient was found to have APOL1 G1 and G2 risk variants. This case supports the role of IFN in inducing APOL1-associated collapsing glomerulopathy.

Intraperitoneal vancomycin treatment of multifocal methicillin-resistant Staphylococcus aureus osteomyelitis in a patient on peritoneal dialysis.

PURPOSE: We report the case of a 2-year-old girl with end-stage renal disease managed by peritoneal dialysis (PD) who developed methicillin-resistant staphylococcal osteomyelitis of the left shoulder and was successfully treated with intraperitoneal (IP) administration of vancomycin for 2 weeks followed by oral clindamycin therapy. SUMMARY: The patient was hospitalized with tactile fever and a 3-day history of worsening fussiness. Radiography of the left shoulder showed findings indicative of osteomyelitis. Vancomycin was administered via central venous line for 3 days, during which time the patient underwent PD 24 hours a day. After magnetic resonance imaging revealed proximal humeral osteomyelitis, septic arthritis of the shoulder joint, and osteomyelitis of the scapula, the patient underwent incision and drainage of the left shoulder joint. Both blood and joint drainage cultures grew methicillin-resistant Staphylococcus aureus that was sensitive to vancomycin. The patient's central venous catheter was removed on hospital day 4; due to difficulties with peripheral i.v. access and a desire to avoid placing a peripherally inserted central venous catheter, vancomycin administration was changed to the IP route, with vancomycin added to the PD fluid. During IP treatment, serum vancomycin levels were maintained at 13.5 to 18.5 mg/L, and the calculated ratio of vancomycin area under the curve to minimum inhibitory concentration was maintained above 400. After completing a 14-day course of IP vancomycin therapy, the patient was switched to oral clindamycin, with subsequent complete resolution of osteomyelitis. CONCLUSION: IP vancomycin was effective for treatment of invasive S. aureus infection in this case. This approach should be considered in patients undergoing PD for whom peripheral i.v. access options are limited and/or not preferred.