Objectives: Cystatin C is emerging as an endogenous marker of glomerular filtration rate. This study sought to assess the usefulness of serum cystatin C as a marker of glomerular filtration rate in comparison with serum creatinine and serum creatinine-based glomerular filtration rate estimations in voluntary kidney donors. 99m Tc-DTPA double plasma sampling method. Glomerular filtration rate-double plasma sampling method was used as a reference value. Results were expressed as means ± SD. Results: The mean age of the participants was 44.23 ± 8.61 years old (19 women, 16 men). The mean serum creatinine was 0.83 ± 0.14 mg/dL, and the mean serum cystatin C was 0.71 ± 0.12 mg/L. Serum cystatin C showed significant correlation with serum creatinine (r = 0.864; P < .001). Glomerular filtration rate-MDRD showed the strongest correlation with glomerular filtration ratedouble plasma sampling method (r = 0.93; P < .001), followed by glomerular filtration rate-CockcroftGault (r = 0.76; P < .001 ), serum creatinine (r = -0.68; P < .001), and serum cystatin C (r = -0.59; P < .001). The mean serum cystatin C values were 22.6% higher in men than in women. There was a significant correlation of serum cystatin C with glomerular filtration rate-Cockcroft-Gault (r = -0.50; P = .002 ), glomerular filtration rate-MDRD (r = -0.59; P < .001 ), and glomerular filtration rate-double plasma sampling method (r = -0.59; P < .001 ). Conclusions: Serum cystatin C is an optimal marker of glomerular filtration rate in voluntary kidney donors.

Emphysematous pyelonephritis is a rare, potentially lethal complication of polycystic kidney disease. Treatment mostly includes emergency nephrectomy of the affected kidney. We report a case of bilateral emphysematous pyelonephritis in a 57-year-old diabetic male with autosomal dominant polycystic kidney disease, who recovered with conservative treatment. Escherichia coli was cultured from the cyst aspirate. He was treated with percutaneous needle aspiration of infected cysts and intravenous antibiotics (meropenem and pazufloxacin) for 3 weeks.

A 60-year-old male patient on maintenance hemodialysis was started on antituberculosis therapy with isoniazid, rifampin, ethambutol, and pyrazinamide for pulmonary tuberculosis. After 4 weeks of therapy, he developed pruritic lesions in the extremities followed by exfoliation. The lesions progressively spread over the entire body. Lesions resolved after withdrawal of antituberculosis medications and administration of oral corticosteroids and antihistamines. After 2 weeks antituberculosis drugs were rechallenged one at a time. Administration of oral pyrazinamide resulted in reappearance of symptoms (pruritis and erythema) within 48 hours. Pyrazinamide was substituted with ofloxacin while other three drugs were restarted without any side effects. The case illustrates a rare but potentially dangerous complication of pyrazinamide therapy.

A 58-year-old male presented with sensory motor polyneuropathy and rapidly progressive renal failure. Investigations revealed marked peripheral eosinophilia and elevated perinuclear antineutrophil cytoplasmic antibody titers. Renal biopsy showed pauci-immune cre-scentic glomerulonephritis with interstitial eosinophil infiltrates. He had no history of asthma. Computed tomography of the chest and X-ray of the paranasal sinuses were normal. On Day 1, the patient developed ileal perforation. Resected ileal segments showed small vessel vasculitis with extravascular eosinophils. A diagnosis of non-asthmatic variant of Churg-Strauss syndrome was made. Renal recovery was achieved in 12 weeks with a combination therapy of corticosteroid and cyclophosphamide. The patient has been relapse-free for 12 months on oral prednisolone therapy.

Antiphospholipid syndrome (APS) often presents as a multisystem disorder characterized by recurrent arterial and venous thrombosis and pregnancy loss. We present a 46-year-old female who was admitted with oliguric acute renal failure. APS was suspected due to prolongation of activated partial thromboplastin time and history of miscarriages. Investigations for secondary causes were normal. Renal biopsy findings revealed thrombotic microangiopathy. A complete recovery of renal function was attained with a combination of plasma exchange and pulse methylprednisolone followed by oral steroids and warfarin. The case is presented for its rarity and therapeutic implications.