Serum and urinary biomarkers for early detection of acute kidney injury following Hypnale spp. envenoming.

BACKGROUND: Hump-nosed pit viper (HNV; Hypnale spp.) bites account for most venomous snakebites in Sri Lanka. Acute kidney injury (AKI) is the most serious systemic manifestation (1-10%) following HNV envenoming. We aimed to identify the value of functional and injury biomarkers in predicting the development of AKI early following HNV bites. METHODS: We conducted a prospective cohort study of patients with confirmed HNV envenoming presenting to two large tertiary care hospitals in Sri Lanka. Demographics, bite details, clinical effects, complications and treatment data were collected prospectively. Blood and urine samples were collected from patients for coagulation and renal biomarker assays on admission, at 0-4h, 4-8h, 8-16h and 16-24h post-bite and daily until discharge. Follow-up samples were obtained 1 and 3 months post-discharge. Creatinine (sCr) and Cystatin C (sCysC) were measured in serum and kidney injury molecule-1 (uKIM-1), clusterin (uClu), albumin (uAlb), ß2-microglobulin (uß2M), cystatin C (uCysC), neutrophil gelatinase associated lipocalin (uNGAL), osteopontin (uOPN) and trefoil factor-3 (uTFF-3) were measured in urine. Definite HNV bites were based on serum venom specific enzyme immunoassay. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to stage AKI. Two patients had chronic kidney disease at 3 month follow-up, both with pre-existing abnormal sCr, and one developed AKI following HNV envenoming. RESULTS: There were 52 patients with confirmed HNV envenoming; median age 48y (Interquartile range [IQR]:40-59y) and 29 (56%) were male. Median time to admission was 1.87h (IQR:1-2.75h). Twelve patients (23%) developed AKI (AKI stage 1 = 7, AKI stage 2 = 1, AKI stage 3 = 4). Levels of five novel biomarkers, the functional marker serum Cystatin C and the damage markers urinary NGAL, cystatin C, ß2-microglobulin and clusterin, were elevated in patients who developed moderate/severe acute kidney injury. sCysC performed the best at 0-4 h post-bite in predicting moderate to severe AKI (AUC-ROC 0.95;95%CI:0.85-1.0) and no biomarker performed better than sCr at later time points. CONCLUSIONS: sCysC appears to be a better marker than sCr for early prediction of moderate to severe AKI following HNV envenoming.

Retroperitoneal abscess with subcutaneous extension: case report of a rare complication of percutaneous renal biopsy.

BACKGROUND: Infective complications following percutaneous renal biopsy are rare, even among immunocompromised. However it is important to be vigilant about such complications, to detect them early and prevent morbidity and mortality. We report a case of retroperitoneal abscess with extension to subcutaneous plane after a renal biopsy. CASE PRESENTATION: A 42-year-old female with long standing cutaneous lupus underwent renal biopsy for evaluation of nephrotic range proteinuria. She was on high dose prednisolone complicated with steroid induced hyperglycaemia. Eight weeks after the biopsy she presented with left flank pain, malaise and fever. There was a tender subcutaneous induration over the biopsy site. Contrast CT abdomen showed a retroperitoneal abscess with subcutaneous extension along the path of the biopsy needle. This was successfully treated with surgical drainage and broad-spectrum antibiotics. CONCLUSIONS: Infections and abscess formation are rare but serious complications of renal biopsy. Immunocompromised state is a potential risk factor. Possible mechanisms and measures for prevention and early detection of this rare complication are discussed.

Dengue fever in a kidney transplant recipient with complicated clinical course: a case report.

BACKGROUND: Dengue fever is the commonest mosquito-borne illness in the tropics and subtropics. Renal transplantation is one of the ever expanding modes of treatment of end-stage renal disease. Hepatitis B is a common infection in South and East Asia, but rare in Sri Lanka. Here we describe a recipient of a renal transplant with a stable graft, on antiviral treatment for hepatitis B infection, developing dengue superinfection and entering a complex clinical course. To the best of our knowledge this is the first report of such a case. CASE PRESENTATION: A 59-year-old Sri Lankan woman developed acute renal failure and needed dialysis support; she had upper gastrointestinal bleeding that needed transfusions, pancytopenia, and a prolonged phase of thrombocytopenia. She eventually recovered from illness, and her renal functions returned to baseline levels. The differences in presentation, signs, symptoms, and mortality of renal transplant recipients infected with dengue fever from the general population are discussed, with possible reasons for altered presentation. CONCLUSIONS: Dengue superinfection in transplant recipients with hepatitis B infection can lead to management difficulties. The recovery can be slow as seen from this case, with prolonged thrombocytopenia.

Salvage of bleeding renal allograft following biopsy, with suture technique: a case report.

BACKGROUND: Percutaneous renal biopsy is a valuable procedure in the management of and prognostication for patients with renal disease. Complications, although rare, occur with renal biopsies. Arteriovenous fistulas and heavy bleeding are notable complications. In this report, we describe simple suturing of the biopsy tract for salvage of a graft destined for a nephrectomy due to a profusely bleeding arteriovenous fistula. CASE PRESENTATION: A 20-year-old Sri Lankan man with end-stage renal disease due to steroid-resistant nephrotic syndrome underwent a renal transplant. He had poor urine output following the surgery, and a renal biopsy was performed to diagnose his renal pathology. He experienced poorly controlled postprocedural hypertension, and he had four episodes of gross hematuria that required blood transfusion. Coil embolization was delayed due to technical issues, and a graft nephrectomy was planned following the fourth episode of hematuria, which was the most severe. A Doppler scan revealed a slender, iatrogenic arteriovenous fistula corresponding to the biopsy tract, with very high flow rates. With knowledge of the anatomy of the fistula, we performed suturing of the tract to obliterate the fistula as a last resort to salvage the graft. The surgical procedure stopped the bleeding, and the patient made a full recovery with an excellent quality of life. CONCLUSIONS: In our patient, a renal transplant biopsy revealed acute tubular necrosis. The incidence and treatment of fistulas and differences in complication rates among native and graft kidney biopsies are discussed.