Clinical characteristics and outcomes of "silent" and "non-silent" peritonitis in patients on peritoneal dialysis

The influence of seasonal factors on the incidence of peritoneal dialysis-associated peritonitis

OBJECTIVES

To investigate the effects of climatic variables on peritoneal dialysis-associated peritonitis (PDAP) among patients receiving PD, such as seasonal variations in temperature and humidity.

METHODS

A retrospective analysis was performed on PD patients, from 1 January 2011, to 31 December 2019. We evaluated the influence of seasonal factors on peritonitis rates and outcomes.

RESULTS

Over the 9-year study period, 667 peritonitis episodes occurred, in 401 PD patients. Diarrhea-associated peritonitis occurred more frequently in summer compared with other seasons. Eating raw and cold food was identified as the primary cause of peritonitis in the summer. More peritonitis episodes occurred during summer. The peritonitis rate associated with gram-negative bacteria (p = 0.050) during summer was higher than those in all other seasons. The gram-negative bacterial peritonitis rate was positively correlated with monthly mean temperature (r = 0.504, p < 0.01) and humidity (r = 0.561, p < 0.01). A similar trend was observed for Enterobacterial peritonitis (temperature: r = 0.518, p < 0.01; humidity: r = 0.456, p = 0.001). Logistic regression analysis showed that summer was a risk factor for peritonitis (p = 0.041). Peritonitis prognosis during summer was significantly worse than those for all other seasons (p = 0.037).

CONCLUSIONS

Seasonal variations exist in the incidence of dialysis-associated peritonitis, with peak incidents caused by gram-negative bacteria in the summer. High average temperature and humidity are associated with significant increases in the gram-negative bacteria and Enterobacterial peritonitis rates. Peritonitis prognosis during summer is worse.

The Association of Cognitive Impairment with Peritoneal Dialysis-Related Peritonitis

Background:Research on the association between cognitive impairment (CI) and peritoneal dialysis (PD)-related peritonitis is limited. Therefore, we investigated whether CI contributed to the risk of PD-related peritonitis.Methods:This prospective cohort study enrolled 458 patients from 5 PD centers between 1 March 2013, and 30 November 2013, and continued until 31 May 2016. We used the Modified Mini-Mental State Examination (3MS) to assess general cognition, the Trail-Making Test to assess executive function, and subtests of the Battery for the Assessment of Neuropsychological Status to assess immediate and delayed memory, visuospatial skills, and language ability. Patients were assigned to CI and non-CI groups based on their 3MS scores. The first episode of peritonitis was the primary endpoint event. Treatment failure of peritonitis was defined as peritonitis-associated death or transfer to hemodialysis. We used competing risk models to analyze the association between CI and the risk of peritonitis. The association of CI with treatment failure after peritonitis was analyzed using logistic regression models.Results:Ninety-four first episodes of peritonitis were recorded during a median follow-up of 31.4 months, 18.1% of which led to treatment failure. No significant group differences were observed for the occurrence, distribution of pathogenic bacteria, or outcomes of first-episode peritonitis. Immediate memory dysfunction was independently associated with a higher risk of PD-related peritonitis (hazard ratio [HR] 1.736, 95% confidence interval [CI] 1.064 - 2.834, p < 0.05), adjusting for confounders.Conclusions:Immediate memory dysfunction was a significant, independent predictor of PD-related peritonitis. Neither general nor specific domains of CI predicted treatment failure of peritonitis.

The Application Analysis of Multiplex Real-Time Polymerase Chain Reaction Assays for Detection of Pathogenic Bacterium in Peritoneal Dialysis-Associated Peritonitis

BACKGROUND/AIMS

To estimate the clinical value of bacterial detection in peritoneal dialysis-associated peritonitis (PDAP) by multiplex real-time polymerase chain reaction (RT-PCR). This study was undertaken to evaluate multiplex RT-PCR for identifying clinically significant bacteria in PDAP.

METHODS

Seventy peritoneal dialysate specimens were collected and traditional bacterial culture and universal primer RT-PCR detection of the bacterial were used.

RESULTS

The positive rate of traditional culture method was 65.71% (46/70) and that of universal primer RT-PCR was 81.42% (57/70). For 6 clinical commonly pathogenic bacteria, multiplex, and monoplex RT-PCR all detected 38 positive ones within the 57 specimens that were detected positive by universal primer RT-PCR. The results of the 2 methods were completely identical. Detecting bacteria by universal primer PCR and Monoplex RT-PCR needs 4-5 and 6-9 h, respectively, while multiplex RT-PCR needs less than 3 h.

CONCLUSION

Our results demonstrated that the multiplex RT-PCR can detect several kinds of bacteria simultaneously and it is also more practical and convenient than monoplex RT-PCR.

The Nitric Oxide Synthase Inhibitor NG-Nitro-L-Arginine Methyl Ester Diminishes the Immunomodulatory Effects of Parental Arginine in Rats with Subacute Peritonitis

The combined treatment of parenteral arginine and the nitric oxide synthase inhibitor N^G-nitro-L-arginine methyl ester (L-NAME) have been shown to improve liver function and systemic inflammation in subacute peritonitic rats. Here, we investigated the effects of single and combined parenteral arginine and L-NAME treatments on leukocyte and splenocyte immunity. Male Wistar rats were subjected to cecal punctures and were intravenously given total parenteral nutrition solutions with or without arginine and/or L-NAME supplementations for 7 days. Non-surgical and sham-operated rats with no cecal puncture were given a chow diet and parenteral nutrition, respectively. Parenteral feeding elevated the white blood cell numbers and subacute peritonitis augmented the parenteral nutrition-induced alterations in the loss of body weight gain, splenomegaly, and splenocyte decreases. Parenteral arginine significantly increased the B-leukocyte level, decreased the natural killer T (NKT)-leukocyte and splenocyte levels, alleviated the loss in body weight gain and total and cytotoxic T-splenocyte levels, and attenuated the increases in plasma nitrate/nitrite and interferon-gamma production by T-splenocytes. L-NAME infusion significantly decreased NKT-leukocyte level, tumor-necrosis factor (TNF)-alpha production by T-splenocytes and macrophages, and interferon-gamma production by T-leukocytes, monocytes, and T-splenocytes, as well as increased interleukin-6 production by T-leukocytes and monocytes and nitrate/nitrite production by T-leukocytes. Combined treatment significantly decreased plasma nitrate/nitrite, the NKT-leukocyte level, and TNF-alpha production by T-splenocytes. Parenteral arginine may attenuate immune impairment and L-NAME infusion may augment leukocyte proinflammatory response, eliminate splenocyte proinflammatory and T-helper 1 responses, and diminish arginine-induced immunomodulation in combined treatment in subacute peritonitic rats.

Serum 25-Hydroxyvitamin D Level Could Predict the Risk for Peritoneal Dialysis-Associated Peritonitis

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BACKGROUND

As an immune system regulator, vitamin D is commonly deficient among patients on peritoneal dialysis (PD), which may contribute to their impaired immune function and increased risk for PD-related peritonitis. In this study, we aimed to investigate whether vitamin D deficiency could predict the risk of peritonitis in a prospective cohort of patients on PD. ♦

METHODS

We collected 346 prevalent and incident PD patients from 2 hospitals. Baseline demographic data and clinical characteristics were recorded. Serum 25-hydroxyvitamin D (25[OH]D) was measured at baseline and prior to peritonitis. The mean doses of oral active vitamin D used during the study period were also recorded. The outcome was the occurrence of peritonitis. ♦

RESULTS

The mean age of patients and duration of PD were 58.95 ± 13.67 years and 28.45 (15.04 - 53.37) months, respectively. Baseline 25(OH)D level was 16.15 (12.13 - 21.16) nmol/L, which was closely associated with diabetic status, longer PD duration, malnutrition, and inflammation. Baseline serum 25(OH)D predicted the occurrence of peritonitis independently of active vitamin D supplementation with a hazard ratio (HR) of 0.94 (95% confidence interval [CI] 0.90 - 0.98) after adjusting for recognized confounders (age, gender, dialysis duration, diabetes, albumin, residual renal function, and history of peritonitis). Compared to the low tertile, middle and high 25(OH)D level tertiles were associated with a decreased risk for peritonitis with HRs of 0.54 (95% CI 0.31 - 0.94) and 0.39 (95% CI 0.20 - 0.75), respectively. ♦

CONCLUSIONS

Vitamin D deficiency evaluated by serum 25(OH)D rather than active vitamin D supplementation is closely associated with a higher risk of peritonitis.