Patterns of CD4/CD8 T-cell ratio in dialysis effluents predict the long-term outcome of peritonitis in patients undergoing peritoneal dialysis

Peritoneal transport status and first episode of peritonitis: a large cohort study

BACKGROUND

Peritonitis is one of the most serious complications of peritoneal dialysis (PD). This study aimed to explore the relationship between peritoneal transport status and the first episode of peritonitis, as well as the prognosis of patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

METHOD

A retrospective cohort study was conducted, analyzing data of CAPD patients from 1st January 2009, to 31st December 2017. Baseline data within 3 months after PD catheter placement was recorded. Cox multivariate regression analysis was performed to determine the risk factors for the first episode of peritonitis, technique failure and overall mortality.

RESULTS

A total of 591 patients were included in our analysis, with a mean follow-up visit of 49 months (range: 27-75months). There were 174 (29.4%) patients who had experienced at least one episode of peritonitis. Multivariate Cox regression analysis revealed that a higher peritoneal transport status (high and high-average) (HR 1.872, 95%CI 1.349-2.599, p = 0.006) and hypoalbuminemia (HR 0.932,95% CI 0.896, 0.969, p = 0.004) were independent risk factors for the occurrence of the first episode of peritonitis. In addition, factors including gender (male) (HR 1.409, 95%CI 1.103, 1.800, p = 0.010), low serum albumin (HR 0.965, 95%CI 0.938, 0.993, p = 0.015) and the place of residence (rural) (HR 1.324, 95%CI 1.037, 1.691, p = 0.024) were independent predictors of technique failure. Furthermore, low serum albumin levels (HR 0.938, 95%CI 0.895, 0.984, p = 0.008) and age (>65years) (HR 1.059, 95%CI 1.042, 1.076, p < 0.001) were significantly associated with the risk of overall mortality of PD patients.

CONCLUSIONS

Baseline hypoalbuminemia and a higher peritoneal transport status are risk factors for the first episode of peritonitis. Factors including male gender, hypoalbuminemia, and residing in rural areas are associated with technique failure, while hypoalbuminemia and age (>65years) are predictors of the overall mortality in PD patients. Nevertheless, the peritoneal transport status does not predict technique failure or overall mortality of PD patients.

Adoptive transfer of DMSO-induced regulatory T cells exhibits a similar preventive effect compared to an in vivo DMSO treatment for chemical-induced experimental encapsulating peritoneal sclerosis in mice

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD). This disease leads to intestinal obstruction with or without peritonitis. The imbalance between the populations of Th17 and regulatory T (Treg) cells (higher Th17 cells and lower Treg cells) is part of the pathogenesis of EPS formation. We demonstrated that dimethyl sulfoxide (DMSO) effectively inhibited autoimmune diabetes recurrence in the islet transplantation of NOD mice via the induction of the differentiation of Treg cells. In this study, we investigated the therapeutic potential of DMSO in the inhibition of EPS formation by a mouse model. Under DMSO treatment, the thickening of the parietal and visceral peritoneum was significantly reduced. The populations of CD4, CD8, and IFN-γ-producing CD4 and CD8 T cells were decreased. The populations of IL-4-producing CD4 T lymphocytes, IL-10-producing CD4 T lymphocytes, CD4 CD69 T lymphocytes and Treg lymphocytes were increased. The expression levels of the cytokines IFN-γ, IL-17a, TNF-α and IL-23, in ascites, were significantly decreased following the DMSO treatment. Furthermore, the differentiation of Treg cells was induced by DMSO from naïve CD4 T cells in vitro, and these cells were adoptively transferred into the EPS mice and significantly prevented EPS formation, exhibiting a comparable effect to the in vivo DMSO treatment. We also demonstrated that the differentiation of Treg cells by DMSO occurred via the activation of STAT5 by its epigenetic effect, without altering the PI3K-AKT-mTOR or Raf-ERK pathways. Our results demonstrated, for the first time, that in vivo DMSO treatment suppresses EPS formation in a mouse model. Furthermore, the adoptive transfer of Treg cells that were differentiated from naïve CD4 T cells by an in vitro DMSO treatment exhibited a similar effect to the in vivo DMSO treatment for the prevention of EPS formation.

Changes in selected subpopulations of lymphocytes in dogs infected with Babesia canis treated with imidocarb

OBJECTIVE

The purpose of this study was to track changes in selected subpopulations of lymphocytes in the blood of dogs infected with Babesia (B.) canis and treated with imidocarb.

MATERIAL AND METHODS

The study included 16 dogs divided into two groups. The first group (n = 6) consisted of healthy control animals. Dogs of the se- cond group (n = 10) were infected with B. canis and after establishment of the diagnosis each animal received a single dose of imido- carb (5 mg/kg). Flow cytometry was used to enumerate several immune cell phenotypes.

RESULTS

It was concluded that the invasion of B. canis contributes to the decreased percentage of CD3+, CD4+, CD8+, CD21+ lymphocytes in the blood of infected animals. The decreased level of tested subpopulations of lymphocytes in group 2 persisted for the entire 12-day period of the test. After the administration of imidocarb, each tested lymphocyte fraction in the blood of the dogs with babesiosis increased, but did not reach physiological values.

CONCLUSION

The presented results indicate that the resolution of clinical signs associated with babesiosis may be related to the stimulation and intensity of cellular immunity, dependent on the CD4+ T cells profile. After administration of imidocarb, the parasitemia is cleared which allows the recovery of the lymphocyte populations.

Effects of zinc supplementation on plasma copper/zinc ratios, oxidative stress, and immunological status in hemodialysis patients

BACKGROUND

Patients undergoing hemodialysis (HD) have low plasma levels of zinc (Zn), high plasma levels of copper (Cu), and exhibit increased oxidative stress, inflammation, and immune abnormalities. We evaluated the effects of Zn supplementation on abnormal plasma Cu/Zn ratios and clinical outcomes in HD patients.

DESIGN AND METHODS

Patients on long-term HD with lower than normal plasma concentrations of Zn (< 80 mg/dL) were randomized to receive daily oral Zn supplements (n = 40) or no supplements (n = 25) for eight weeks. Age- and sex-matched healthy individuals served as a control group (n = 38). A number of clinical parameters were measured before and after the supplementation period.

RESULTS

Compared with healthy subjects, patients had significantly elevated plasma Cu concentrations and Cu/Zn ratios, as well as higher levels of oxidative stress and pro-inflammatory cytokines. Patients who received Zn supplements for eight weeks had higher plasma concentrations of Zn and lower concentrations of Cu, along with reduced Cu/Zn ratios, oxidative stress status, and inflammatory responses compared to patients who did not receive Zn. Patients receiving Zn also showed significantly higher percentages of CD4 and CD19 lymphocytes, and elevated CD4/CD8 ratios.

CONCLUSIONS

Zn supplementation ameliorates abnormally high plasma Cu/Zn ratios and may reduce oxidative stress, improve inflammatory status, and maintain immune function in patients undergoing long-term HD.

The dose-dependent immunoregulatory effects of the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester in rats with sub-acute peritonitis

BACKGROUND

Chronic inflammation accompanied by arginine deficiency, immune dysfunction, and excess nitric oxide (NO) production is a clinical condition found in patients with peritonitis. A previous study showed that the nonselective NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) may facilitate the metabolism of the immune nutrient arginine without altering NO homeostasis in rats with sub-acute peritonitis. Here, we investigated the effects of L-NAME on the immunocytic subpopulation distribution and response.

MATERIALS AND METHODS

Male Wistar rats with cecal puncture-induced peritonitis were administered parenteral nutrition solutions supplemented with 0 (CPP group), 5 (LNA group), 25 (MNA group) or 50 (HNA group) mg · kg(-1) · day(-1) of L-NAME for 7 days. Parenteral-fed sham-operated rats (TPN group) and orally-fed healthy rats (R group) were included as controls.

RESULTS

The TPN group had significantly increased spleen weights and levels of plasma nitrite/nitrate (NOx), circulating white blood cells (WBC), and splenocytic T cells, as well as significantly decreased levels of cytotoxic T- and B-leukocytes and B-splenocytes compared to the R group. The CPP group had significantly decreased levels of plasma NOx and concanavalin (Con) A-stimulated interferon (IFN)-γ and interleukin (IL)-2 production by leukocytes and significantly increased production of Con A-stimulated tumor necrosis factor (TNF)-α and lipopolysaccharide (LPS)-stimulated IFN-γ in the leukocytes. In addition, the LNA and MNA groups had significantly decreased spontaneous IL-6 and Con A-stimulated TNF-α and IFN-γ production by the leukocytes while the HNA group had significantly increased LPS-stimulated TNF-α and Con A-stimulated IFN-γ and IL-2 production by the splenocytes compared to the CPP group.

CONCLUSIONS

Low-dose L-NAME infusion may suppress proinflammatory and T-helper-1 (Th1) response in leukocytes, and high-dose infusion may activate the proinflammatory response in splenic macrophages and Th1 response in T-splenocytes in rats with sub-acute peritonitis.

Cu/Zn ratios are associated with nutritional status, oxidative stress, inflammation, and immune abnormalities in patients on peritoneal dialysis

OBJECTIVES

We evaluated the relationship of the plasma copper/zinc (Cu/Zn) ratio with nutritional status, inflammation, oxidative stress, and immune function in peritoneal dialysis patients.

DESIGN AND METHODS

Clinical and laboratory parameters were measured in patients (n=45) and age- and sex-matched healthy individuals (n=30).

RESULTS

There were significant negative correlations of the Cu/Zn ratio with nutrition-related parameters (body mass index [BMI], creatinine, hemoglobin, and albumin) and antioxidant (vitamin C and E) levels and positive correlations of the Cu/Zn ratio with the levels of high sensitivity C-reactive protein (hs-CRP) and oxidation products (malondialdehyde [MDA] and protein carbonyl). The Cu/Zn ratio was negatively correlated with the percentages of B- and T-lymphocyte subsets and the ratio of CD4/CD8 antigens.

CONCLUSIONS

In peritoneal dialysis patients, elevated Cu/Zn ratios are associated with malnutrition, increased oxidative stress, inflammation, and disrupted immune status.

CD4/CD8 T-cell ratio in peritoneal dialysis effluents predicts the outcome of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis

This study aimed to clarify the role of peritoneal T-lymphocytes in peritoneal immune defense mechanisms. This study was designed to examine the changes in T-cell subpopulations during peritonitis in patients treated with continuous ambulatory peritoneal dialysis (CAPD). Our observations were correlated to responses to treatment and with outcomes. The present study was carried out in 20 patients (8 males, 12 females) under CAPD. Peritonitis was diagnosed according to the criteria defined by the Ad Hoc Advisory Committee on Peritonitis Management. Peritoneal dialysate effluent (PDE) samples were collected from our patients, and lymphocyte subsets (CD2+, CD3+, CD3+/4+, CD3+/8+, CD3-/16+56+, CD4/CD8 ratio) were quantitated by using monoclonal antibodies. CD4/CD8 ratio was measured every day during peritonitis until the patients had completely recovered. The serial measurements of the CD4/CD8 ratio made in the PDE during peritonitis followed two patterns: the first pattern was characterized by a progressive increase in the CD4/CD8 ratio. The CD4/CD8 ratios on days 5, 6, and 7 were significantly higher than those on day 1 (P < 0.05). Overall, the patients who exhibited pattern 1 had favorable clinical courses. The second pattern was characterized by high initial CD4/CD8 ratios, which progressively decreased significantly (P < 0.05). This second pattern was associated with a delayed clinical response to treatment. Symptoms and signs of peritonitis persisted beyond 72 h. The pattern of the CD4/CD8 ratio in PDE may determine the outcome of peritonitis in CAPD patients.

Impact of nutritional status on peritonitis in CAPD patients

OBJECTIVE

To determine the impact of nutritional status on peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) in a developing country.

METHODS

56 patients with end-stage renal disease on CAPD were randomly selected for this study. These patients were assessed for nutritional status and peritonitis episodes. Nutritional parameters were assessed by anthropometry, diet, body mass index (BMI), Nutritional Risk Index (NRI), serum albumin level, and Subjective Global Assessment (SGA). Based on SGA, patients were categorized into either group 1 (malnutrition, n = 31) or group 2 (normal nutritional status, n = 25). Peritonitis was considered the primary outcome and was compared between the two groups.

RESULTS

Demographic profiles, Kt/V, creatinine clearance, and mean follow-up of the two groups were similar. Number of peritonitis episodes was significantly higher in patients with malnutrition (25/31) compared to patients with normal nutritional status (4/25) (p = 0.001). Mean peritonitis rate per patient per year was also significantly higher in patients with malnutrition (0.99 +/- 1.07) compared to patients with normal nutritional status (0.18 +/- 0.42) (p = 0.007). On univariate analysis, malnutrition based on SGA (p = 0.009), NRI (p = 0.02), serum albumin level (p = 0.005), and calorie intake (p = 0.006) was a significant predictor of peritonitis. On multivariate Cox regression analysis, only SGA (p = 0.001, odds ratio 0.08, 95% confidence interval 0.02-0.36) was found to be a significant predictor of peritonitis. On general linear model, the observed power of prediction of peritonitis was 0.96 based on SGA. On Kaplan-Meier survival analysis, peritonitis-free survival in patients with normal nutrition (42 months) was significantly higher compared to patients with malnutrition (21 months) based on SGA (log rank p = 0.003).

CONCLUSION

We conclude that peritonitis rate is high in patients with malnutrition and that malnutrition indices, especially SGA, can predict the peritonitis rate in CAPD patients.

Interleukin-12 and -18 Levels in Peritoneal Dialysate Effluent Correlate With the Outcome of Peritonitis in Patients Undergoing Peritoneal Dialysis: Implications for the Type I/Type II T-Cell Immune Response

BACKGROUND

We previously showed that a positive impact of peritoneal defense response on the outcome of peritoneal dialysis (PD)-related peritonitis is characterized by an increased pattern of peritoneal CD4/CD8 T-cell ratio with a predominant CD4(+)-T helper subtype 1 phenotype. To further explore longitudinal changes in peritoneal immunity during PD-related peritonitis, we examined the production of interleukin 12 (IL-12), IL-18, and interferon gamma (IFN-gamma) in peritoneal dialysate effluent (PDE) and kinetic expression of the transcription factors T box expressed in T cells (T-bet) and guanine adenine thymine adenine (GATA) binding protein 3 (GATA-3) in peritoneal T cells during peritonitis. Correlations between these observations and responses to antibiotics were analyzed.

METHODS

IL-12, IL-18, and IFN-gamma protein and IFN-gamma, T-bet, and GATA-3 messenger RNA (mRNA) were measured in PDE during various phases of peritonitis in 40 patients undergoing PD. Patients were divided into 2 groups according to whether they had a rapid versus delayed response to antibiotic treatment.

RESULTS

In the early phase of peritonitis, IL-12, IL-18, and IFN-gamma levels in PDE were significantly greater in the rapid-response group (P < 0.05). Changes in peritoneal IL-12 and IL-18 levels preceded changes in IFN-gamma levels. The kinetics of IFN-gamma, T-bet, and GATA-3 mRNA expression in peritoneal T cells, measured by means of real-time polymerase chain reaction, differed between the 2 groups. In the rapid-response group, IFN-gamma and T-bet mRNA expression increased, whereas that of GATA-3 decreased over time. Results were opposite in the delayed-response group, with IFN-gamma and T-bet levels decreasing and GATA-3 levels increasing over time.

CONCLUSION

These data suggest that local IL-12 and IL-18 production is part of a protective early immune response to PD-related peritonitis. High IL-12 and IL-18 levels in PDE during the early phase of peritonitis correlated with a predominant type 1 immune response and favorable outcome.