#913 PD-peritonitis diagnosis using novel, rapid diagnostic assay RenoTact®: a study on pre-clinical performance and usability

Abstract Background and Aims Peritonitis is a serious complication of peritoneal dialysis (PD) and the main cause of PD failure. Early diagnosis and treatment are necessary to enhance patient care, as the current standard of care is based on symptoms and visible cloudy dialysate followed up by a culture result. There is a risk of a delay in treatment and/or overtreatment when (broad-spectrum) antibiotics are given prior to the growth results are in, which can take 48–72 hours. A diagnostics tool that rapidly detects viable pathogens in (early-stage) peritonitis would be beneficial in the standard-of-care process. RenoTact® intends to meet this need. To explore the preliminary sensitivity and specificity of RenoTact® in detecting peritonitis in PD patient samples compared to the standard of care, a performance pilot study was conducted at the Martini Hospital (Groningen, the Netherlands). Additionally, PD-peritonitis detection in a home-setting, where peritonitis can be detected earlier to the standard of care, was explored during a usability pilot study; are PD patients compliant to the RenoTact® test protocol in a home setting. Method As part of the performance study, dialysates that were brought into the clinic from both symptomatic and asymptomatic adult PD patients were tested, using RenoTact®. All samples were tested within 24 hours of collection, from patients who had been on PD for at least 1 month. All PD patients suspected of peritonitis were managed according to the ISPD peritonitis guidelines and recommendations. For the usability-compliance study, dialysate was collected for a period of 3 months on two fixed days per week, from the 13 participating patients who had to provide a waste fluid sample on the day of collection. A courier picked up the samples from the patients’ place of residence on each sample collection day of the study. The samples were subsequently analyzed with RenoTact® in the laboratory. Results For the performance evaluation, 98 peritoneal dialysis waste fluid patient samples were tested using the RenoTact® assay (Fig. 1). All patients (n = 7) with a peritonitis according to the ISPD guidelines tested positive on the RenoTact® assay, and all negative patients (n = 91) by ISPD guidelines tested negative on RenoTact®. A sensitivity of 100% (95% CI: 64.6%–100.0%) and a specificity of 100% (95% CI: 95.9%–100.0%) were observed. For the usability-compliance study, 13 participants collected dialysates at home, twice a week for 3 months, yielding 290 samples, with a compliance rate of 99.0% (95% CI: 97.0%–99.7%). Conclusion Despite the evident limitations of the present studies, the preliminary pre-clinical results do not only exhibit a 100% sensitivity/specificity, but also show patients are motivated to work with a protocol set-up that includes testing twice a week. This could contribute to the early, and direct diagnosis of peritonitis, thereby contributing to the appropriate treatment sooner and helping to minimize further complications.