Metformin associated lactic acidosis in Auckland City Hospital 2005 to 2009

AIM： To determine the incidence, clinical characteristics and outcomes of patients with metformin associated lactic acidosis （MALA）.METHODS： Auckland City Hospital drains a population of just over 400000 people. All cases presenting with metabolic acidosis between July 2005 and July 2009 were identifed using clinical coding. A retrospective case notes review identifed patients with MALA. Prescribing data for metformin was obtained from the national pharmaceutical prescribing scheme.RESULTS： There were 42 cases of metabolic lactic acidosis over 1718000 patient years. There were 51000 patient years of metformin prescribed to patients over the study period. There were thirty two cases of lactic acidosis due to sepsis, seven in patients treated with metformin. Ten cases of MALA were identified. The incidence of MALA was estimated at 19.46 per 100000 patient year exposure to metformin. The relative risk of lactic acidosis in patients on metformin was 13.53 （95%CI： 7.88-21.66） compared to the general population. The mean age of patients with MALA was 63 years, range 40-83 years. A baseline estimated glomerular fltration rate was obtained in all patients and ranged from 23-130 mL/min per 1.73 m^2. Only two patients had chronic kidney disease G4.Three patients required treatment with haemodialysis. Two patients died.

Outcomes of renal transplant recipients with BK virus infection and BK virus surveillance in the Auckland region from 2006 to 2012

AIM To evaluate incidence, risk factors and treatment outcome of BK polyomavirus nephropathy(BKVN) in a cohort of renal transplant recipients in the Auckland region without a formal BK polyomavirus(BKV) surveillance programme.METHODS A cohort of 226 patients who received their renal transplants from 2006 to 2012 was retrospectively reviewed.RESULTS Seventy-six recipients(33.6%) had a BK viral load(BKVL) test and 9 patients(3.9%) developed BKVN. Cold ischaemia time(HR = 1.18, 95%CI: 1.04-1.35) was found to be a risk factor for BKVN. Four recipients with BKVN had complete resolution of their BKV infection; 1 recipient had BKVL less than 625 copies/mL; 3 recipients had BKVL more than 1000 copies/mL and 1 had graft failure from BKVN. BKVN has a negative impact on graft function [median estimated glomerular filtration rate(eG FR) 22.5(IQR 18.5-53.0) mL /min per 1.73 m^2, P = 0.015), but no statistically significant difference(P = 0.374) in renal allograft function was found among negative BK viraemia group [median e GFR 60.0(IQR 48.5-74.2) mL /min per 1.73 m^2), positive BK viraemia without BKVN group [median eG FR 55.0(IQR 47.0-76.0) mL /min per 1.73 m^2] and unknown BKV status group [median eG FR 54.0(IQR 43.8-71.0) mL /min per 1.73 m^2]. The incidence and treatment outcomes of BKVN were similar to some centres with BKV surveillance programmes.CONCLUSION Recipients with BVKN have poorer graft function. Although active surveillance for BKV has been shown to be effective in reducing incidence of BKVN, it should be tailored specifically to that transplant centre based on its epidemiology and outcomes of BKVN, particularly in centres with limited resources.