Development and validation of a novel prediction model for predicting renal function recovery after diversion in patients with obstructive uropathy.

OBJECTIVE: To develop and validate a novel prediction model predicting renal function recovery following diversion in patients with obstructive uropathy (OU) to the emergency department (ED). METHODS: After a systematic literature search, a novel prediction model called PGIMER Obstructive Uropathy Score (POUS) was constructed including five variables: age (<60 or >60 years), duration of symptoms (<4 or >4 weeks), presence of solitary functioning kidney, baseline hemoglobin levels and venous blood pH. This model was then validated in a prospective, observational single-center study of patients presenting with OU caused by various etiologies. Patients with OU and raised serum creatinine (>2 mg/dL) presenting to our ED were included. Renal function recovery was defined as creatinine value <1.5 mg/dL at 4 weeks following diversion. RESULTS: In this study, 174 consecutive patients with OU were recruited, and 74 (42.5%) patients had renal function recovery. All the variables included in the POUS were noted to be statistically significant on univariate analysis. On multivariate logistic regression analysis, only POUS was identified as an independent predictor of renal function recovery. On receiver operating curve analysis, the area under the curve for POUS was 0.832 for predicting recovery. A POUS of 5 or more had specificity and sensitivity of 83% and 73.6%, respectively, in predicting renal function recovery. The goodness of fit and calibration plots showed good concordance of the predicted values with the observed values. CONCLUSIONS: The POUS model is an accurate and simple-to-use tool for predicting renal function recovery. POUS model requires external validation prior to clinical use in different populations.

Novel Flow Cytometry-Based Method for Detection of Anti-HLA Complement Activating Donor-Specific Antibodies in Renal Transplant Recipients and Its Comparison With Other Conventional Detection Methods.

BACKGROUND: Presence of preformed donor specific antibodies (DSAs) detected by complement-dependent cytotoxicity (CDC-XM) is a strong contraindication for transplant. However, it has limitations including its sensitivity and its inability to distinguish between HLA-specific and other non-HLA-specific antibodies. In this study, we standardized CDC-XM by flow cytometry and determined its relevance by comparing its results with other methods of DSA detection, such as routine CDC-XM, antibody binding assay by flow cytometry (FC-XM), and Luminex-based crossmatch assays, such as Luminex crossmatch (LXM) and virtual crossmatch (VXM). MATERIALS AND METHODS: A total of 79 serum samples were tested for DSAs by the flow cytometric complement-dependent cytotoxicity crossmatch assay (FC-CDC-XM) and then the results of FC-CDC-XM were compared with other detection methods such as CDC-XM, FC-XM, LXM, and VXM. RESULTS: We found that the FC-CDC-XM assay is more sensitive than routine CDC-XM. Out of total 79 sera, 24 sera were detected positive (T cells positive: 1 case and B cells positive: 23) by FC-CDC-XM as compared with 3 sera using CDC-XM; these 3 sera also showed positivity by FC-CDC-XM. After FC-XM assay, 23 samples were positive by FC-XM and out of these 23 samples, 13 were also positive by FC-CDC-XM. On comparing the FC-CDC-XM results with VXM and LXM, 10 sera of 24 FC-CDC-XM positive had HLA class II antibodies detected on a Luminex platform. CONCLUSIONS: The FC-CDC-XM is a more sensitive and specific method for detection of HLA-specific complement-fixing antibodies than CDC-XM and FC-XM. FC-CDC-XM should be used in tissue-typing laboratories after intra- and inter- laboratory validation.

Incidence and Risk Factors for Hepatitis C Virus and Hepatitis B Virus Seroconversion in End-Stage Renal Failure Patients on Maintenance Hemodialysis.

BACKGROUND: Renal replacement therapy in the form of either dialysis or transplantation is the only option for end-stage renal disease (ESRD). Blood-borne infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV) are of special concern in these patients because of their high incidence. Although there are sufficient data from the developed world, there is scarcity of data from developing countries such as India. METHODS: All newly diagnosed ESRD patients initiated on hemodialysis after attending the Department of Nephrology, PGIMER, Chandigarh between January 2015 and October 2015 were included in the study. All the subjects were initially screened for HCV and HBV serology status and subsequent HCV and HBV status on follow-up at the end of 6 months and evaluated by standardized precoded questionnaires and biochemical examinations. Univariate and multivariate analyses were done to identify the risk factors for seroconversion. RESULTS: A total of 196 patients were recruited for the study after confirming seronegative status. At the end of 6 months, 61 patients lost to follow-up. Anti-HCV antibody had shown moderate association to HCV RNA testing at the end of 6 months by kappa test. Out of 135, 16.3% seroconverted to HCV RNA positive and 0.7% patient became hepatitis B surface antigen positive. Isolation of dialysis machine and nursing staff was associated with lower seroconversion. CONCLUSION: In a real-life scenario, HCV seroconversion is observed in 15% of the patients initiated on hemodialysis. Isolation of both dialysis machine and personnel was associated with lower seroconversion.