Validation of an international prediction model including the Oxford classification in Korean patients with IgA nephropathy.

BACKGROUND: Recently, a new international risk prediction model including the Oxford classification was published which was validated in a large multi-ethnic cohort. Therefore, we aimed to validate this risk prediction model in Korean patients with IgA nephropathy. METHODS: This retrospective cohort study was conducted with 545 patients who diagnosed IgA nephropathy with renal biopsy in three medical centers. The primary outcome was defined as a reduction in estimated glomerular filtration rate (eGFR) of >50% or incident end-stage renal disease (ESRD). Continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) were used to validate models. RESULTS: During the median 3.6 years of follow-up period, 53 (9.7%) renal events occurred. In multivariable Cox regression model, M1 (hazard ratio [HR], 2.22; 95% confidence interval [CI], 1.02-4.82; p = .043), T1 (HR, 2.98; 95% CI, 1.39-6.39; p = .005) and T2 (HR, 4.80; 95% CI, 2.06-11.18; p < .001) lesions were associated with increased risk of renal outcome. When applied the international prediction model, the area under curve (AUC) for 5-year risk of renal outcome was 0.69, which was lower than previous validation and internally derived models. Moreover, cNRI and IDI analyses showed that discrimination and reclassification performance of the international model was inferior to the internally derived models. CONCLUSION: The international risk prediction model for IgA nephropathy showed not as good performance in Korean patients as previous validation in other ethnic group. Further validation of risk prediction model is needed for Korean patients with IgA nephropathy.

Validation of risk prediction tools in elderly patients who initiate dialysis.

PURPOSE: The number of elderly patients with end-stage renal disease on maintenance dialysis therapy is gradually increasing. The elderly population has difficulties in making decisions regarding initiation of dialysis treatment because of their high morbidity and frailty. The purpose of this study was to determine the best prognostic tool in predicting short-term mortality in elderly patients undergoing dialysis. METHODS: This study is a multicenter retrospective study. We enrolled patients, aged ≥ 75 years, who began hemodialysis at three university hospitals in Korea from January 2010 to December 2016. We applied two comorbidity-based score tools (Thamer and Wick, each consisting of seven variables) and the Clinical Frailty Scale (CFS, seven scales), which were validated for mortality prediction in elderly incident patients. Patient's information was obtained from electronic medical records in the participating center, and mortality data (up to December 2016) were obtained from the Korean National Statistical Office. Models were compared using the area under the receiver operating characteristic curve. RESULTS: Among the 219 patients enrolled in this study, the 3- and 6-month mortality rates were 31 (14.4%) and 48 (22.4%), respectively. Receiver operating characteristic curve analysis revealed that both score systems and the CFS showed similar performance while predicting 3- and 6-month mortality. The scores from these indices correlated with survival time. CONCLUSION: Predicting short-term mortality and long-term survival time for elderly patients is possible using the Thamer and Wick scores and the CFS.

Clinical features and treatment outcomes of septic arthritis due to Mycobacterium massiliense associated with intra-articular injection: a case report.

BACKGROUND: There are increasing reports on nosocomial Mycobacterium massiliense infection, but septic arthritis and osteomyelitis because of that microorganism is rare. This report focuses on the clinical aspects of M. massiliense arthritis outbreak concurrent with soft tissue infection. CASE PRESENTATION: An outbreak of septic arthritis among patients who had been injected at a single clinic occurred in South Korea between April and September 2012. This may be associated with repeated injection of triamcinolone contaminated with M. massiliense. Nine of the Korean patients visited our hospital complaining of painful swelling of the knees. During treatment course, patients are suffered from soft tissue abscess around the injection site. Acid-fast bacilli culture for infected tissue was positive in five patients, and polymerase chain reaction for non-tuberculous mycobacteria was positive in four patients. They were treated with antibiotics, repeated arthroscopic surgeries, incision and drainage for a long time. All patients were eventually cured but three patients have suffered from a decreased range of motion. CONCLUSION: Early clinical suspicion and microbiological diagnosis are key factors in reducing morbidity since septic arthritis with M. massiliense manifests late after the injection and treatment of it is a laborious process.