Microbiological diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

The fast and accurate etiological diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis is essential. The concentration of larger volumes of peritoneal fluids may yield more isolates than conventional methods. The removal of antibiotics present in the fluids as a consequence of therapy by washing or using antibiotic-removing resins increases the yield considerably. The use of anaerobic culture media is justified if fecal organisms are suspected as the cause of the infection.     

Laboratory diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

The clinical course and laboratory diagnosis of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis was studied in 32 consecutive episodes. Peritonitis was associated with a failure in aseptic technique in eight episodes and with an exit-site infection in four episodes. Intraperitoneal vancomycin and ceftazidime were safe, effective, and convenient. Most patients administered their antibiotics at home, and symptoms usually resolved by day 4. Culture of the deposit obtained by centrifugation of 50 ml of effluent after leukocyte lysis provided the best rate of recovery (84% culture positive) but was technically demanding. Filtration of the same volume without leukocyte lysis was simple to perform and almost as effective. Enrichment was less satisfactory (65% culture positive) owing to the presence of antibiotic or infection with fastidious microorganisms. Culture of 50 ml of effluent after concentration by a commonly used laboratory technique, centrifugation without leukocyte lysis, performed poorly (59% culture positive at 48 h), as this method caused sequestration and death of microorganisms within the leukocytes. Culture of nearly 1 liter of effluent from 33 asymptomatic patients by the same techniques yielded no microorganisms.     

Corynebacterium group JK peritonitis in patients on continuous ambulatory peritoneal dialysis

Summary Corynebacterium group JK is described as the aetiologic agent of a second episode of peritonitis which occurred after a period of antibiotic treatment for likely endogenous peritonitis. Inclusion of vancomycin is suggested for treatment of continuous ambulatory peritoneal dialysis (CAPD) peritonitis in patients colonized by these multiresistant bacteria.     

Recombinant interferon-gamma inhibits the expression of IL-4 receptors on human lymphocytes.

Interferon gamma (IFN-gamma) has been shown to inhibit many of the activities of IL-4, including the induction of IgE synthesis and the proliferation of T cell clones. Here we demonstrate that IFN-gamma is able to inhibit the expression of IL-4 receptors on peripheral blood lymphocytes from both normal healthy donors and from patients with chronic lymphocytic leukaemia. Inhibition was shown to be dose-dependent and did not affect the binding affinity of the receptor as shown by Scatchard analysis. IFN-gamma was unable to displace labelled IL-4 from its membrane receptor, which demonstrates that IFN-gamma and IL-4 do not compete for the same membrane binding protein. The ability of IFN-gamma to down-regulate IL-4 receptors may be important in controlling certain immune responses.     

Laboratory diagnosis of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis

A simple laboratory method for culture of continuous ambulatory peritoneal dialysis (CAPD) fluids is described. Guidelines for antimicrobial therapy are discussed based on results from 18 patients studied over an 11-week period. Cephalosporins appeared to be a rational choice for therapy while awaiting laboratory results.     

Staphylococcal peritonitis in patients on continuous peritoneal dialysis.

During 1984, 35 patients undergoing continuous peritoneal dialysis experienced 77 cases of peritonitis with 55 cases (71.4%) related to staphylococci. Coagulase-negative staphylococci were isolated in 41 cases, while Staphylococcus aureus was found in 14. A coexisting tunnel infection was more often associated with S. aureus (7/14) than with coagulase-negative staphylococci (2/41) (P less than 0.01). Likewise, eradication of the infection necessitated catheter removal more frequently with S. aureus (5/14) than with coagulase-negative staphylococci (2/41) (P less than 0.01). Of the 41 coagulase-negative staphylococci, 35 were characterized as to species, adherence, and production of two exopolysaccharides. Staphylococcus epidermidis was the most frequent coagulase-negative species (29/35). Peritonitis cases caused by coagulase-negative staphylococci that lacked adherence and exopolysaccharides were more frequently associated with complications (4/6) than were those organisms with either or both properties of adherence or exopolysaccharide production (5/29). There were no appreciable differences in antibiotic susceptibilities. Staphylococcal peritonitis remains a significant cause of morbidity in continuous peritoneal dialysis patients. The incidence of complications was not directly linked to staphylococcal properties of adherence or exopolysaccharide production.     

Laboratory diagnosis of peritonitis in patients treated with continuous ambulatory peritoneal dialysis

Patients treated with continuous ambulatory peritoneal dialysis (CAPD) are constantly exposed to microbial invasion of the peritoneal cavity and rapid microbiological diagnosis of peritonitis is essential. Aseptic peritonitis is diagnosed in a high proportion of episodes when small volumes of dialysate are cultured. The aims of this study were to enumerate the microorganisms associated with clinical peritonitis and compare the efficacy of various culture systems for laboratory diagnosis of peritonitis. Four qualitative culture systems were compared: low (1 ml) volume and high (10 ml) volume inoculations of broth media, centrifugation (10 ml) followed by culture of the sediment and filtration (less than or equal to 100 ml) followed by culture of the filter. The pour plate and drop plate were the 2 quantitative methods used. Results of this study indicate that culture of 10 ml fluid volumes is comparable to culture of larger volumes sampled by filtration. Low volume cultures of fluid resulted in a lower proportion of positive cultures. The low numbers of viable microorganisms often found in dialysate from patients with peritonitis supports the concept of culturing a minimum of 10 ml of fluid.     

Microbiological aspects of peritonitis associated with continuous ambulatory peritoneal dialysis.

The process of continuous ambulatory peritoneal dialysis has provided a useful, relatively inexpensive, and safe alternative for patients with end-stage renal disease. Infectious peritonitis, however, has limited a more widespread acceptance of this technique. The definition of peritonitis in this patient population is not universally accepted and does not always include the laboratory support of a positive culture (or Gram stain). In part, the omission of clinical microbiological findings stems from the lack of sensitivity of earlier microbiological efforts. Peritonitis results from decreased host phagocytic efficiency with depressed phagocytosis and bactericidal capacity of peritoneal macrophages. During episodes of peritonitis, fluid movement is reversed, away from the lymphatics and peritoneal membrane and toward the cavity. As a result, bloodstream infections are rare. Most peritonitis episodes are caused by bacteria. Coagulase-negative staphylococci are the most frequently isolated organisms, usually originating from the skin flora, but a wide array of microbial species have been documented as agents of peritonitis. Clinical microbiology laboratories need to be cognizant of the diverse agents so that appropriate primary media can be used. The quantity of dialysate fluid that is prepared for culture is critical and should constitute at least 10 ml. The sensitivity of the cultural approach depends on the volume of dialysate, its pretreatment (lysis or centrifugation), the media used, and the mode of incubation. The low concentration of microorganisms in dialysate fluids accounts for negative Gram stain results. Prevention of infection in continuous ambulatory peritoneal dialysis patients is associated with the socioeconomic status of the patient, advances in equipment (catheter) technology, and, probably least important, the application of prophylactic antimicrobial agents.     

IgE production in atopic patients is not related to IL-4 production.

To analyse whether there is a general defect in T or B cell function in atopic individuals we have measured cytokine and IgE production by peripheral blood lymphocytes, isolated from 19 atopic donors (17 asthma/rhinitis and two dermatitis patients) in comparison with 19 non-atopic controls. After stimulation of lymphocytes with anti-CD2 and anti-CD28, we found no significant difference in IL-2, IL-4 and interferon-gamma (IFN-gamma) production. To examine the correlation between the production of IgE and IL-4, we stimulated lymphocytes with anti-CD2 and rIL-2. Under this condition both T cell IL-4 and B cell IgE production can be measured. No significant difference was found for the amount of IgE and IL-4 produced between the two groups (P > 0.05). The non-atopic donors showed a good correlation between IL-4 and IgE production (r = 0.70). Surprisingly, within the atopic group there was no correlation between IgE and IL-4 production at all (r = -0.04). The ratio of IgE to IL-4 was higher (although not significantly) in the atopic group. Our data suggest that in atopic donors IgE production is less dependent on IL-4, and that other cytokines are involved.     

匹多莫德对腹膜透析腹膜炎患者的疗效

目的:观察口服匹多莫德对腹膜透析相关性腹膜炎的疗效.方法:选取2014年5月至2016年5月在华润武钢总医院肾内科住院的130名腹膜透析相关性腹膜炎患者,随机分为治疗组与对照组,对照组给予头孢唑啉联合头孢他啶,治疗组在对照组基础上加用匹多莫德片.比较两组一般情况、初治及2周后有效率、换液次数及微炎症、血脂与免疫学指标.结果:治疗组与对照组在年龄、性别、透析龄、原发病、体重、改良定量主观整体评分(Modified Quantitative Subjective Global Assessment,MQSGA)、血尿素氮(blood urea nitrogen,BUN)、血肌酐(serum creatinine,Scr)、内生肌酐清除率(endogenous creatinine clearance rate,Ccr)等方面差异无统计学意义;对照组与治疗组之间菌谱差异无统计学意义;治疗组与对照组初治有效率分别为77.7％ vs.80.0％,差异无统计学意义(x2=0.18,P=0.66);2周后的有效率分别为93.3％ vs.82.2％,差异有统计学意义(x2=4.56,P=0.03);治疗组与对照组至透出液清亮的换液次数分别为4.60±1.90 vs.5.30±2.60,差异无统计学意义(t=1.75,P=0.08);治疗组与对照组至发热消失的换液次数分别为7.00±3.30 vs.7.70±2.50,差异无统计学意义(t=1.36,P=0.17);治疗组与对照组至腹痛消失的换液次数分别为7.75±2.5 vs.11.38±2.70,差异有统计学意义(t=7.95,P＜0.001),治疗组至腹痛消失的次数显著少于对照组;治疗组与对照组至白细胞计数＜50/μL的换液次数分别为8.60±3.60 vs.13.75±4.70,差异有统计学意义(t=7.10,P＜0.001),治疗组白细胞计数＜50/μL的次数显著少于对照组;治疗后治疗组和对照组较治疗前超敏C反应蛋白(high-sensitivity C-reactive protein,hs-CRP)、高迁移率族蛋白1 (high mobility group box-1 protein,HMGB1)显著降低,治疗组hs-CRP、HMGB-1显著低于对照组,在血脂指标中,治疗组与对照组在治疗前和治疗后2周指标均无显著差异,免疫学指标中治疗组在治疗后免疫球蛋白G与免疫球蛋白A显著上升.结论:匹多莫德能够改善腹膜透析相关性腹膜炎抗生素治疗的有效率,缩短患者的临床症状和体征消失时间,同时改善患者的微炎症状态、免疫学功能.     

Serological response to coagulase-negative staphylococci in patients with peritonitis on continuous ambulatory peritoneal dialysis

Sera and dialysis effluent from 20 patients on continuous ambulatory peritoneal dialysis (CAPD) with coagulase-negative staphylococcal (CNS) peritonitis were examined by immunoblotting for antibody activity against CNS. Immunoblotting was highly sensitive and demonstrated significantly greater antibody activity in serum and dialysate of infected patients compared with that of uninfected CAPD patients or healthy volunteers. Fourteen of 20 infected CAPD patients had strong antibody activity (> 7 bands); one patient had equivocal activity. Five patients had weak antibody activity, two of whom suffered from recurrent peritonitis with distinguishable CNS strains despite a satisfactory CAPD technique. One patient with a poor CAPD technique had strong antibody activity, but suffered from recurrent peritonitis. Examination of sequential sera suggested that seroconversion occurred soon after insertion of the Tenckhoff catheter, possibly in the absence of clinical infection. Antibody activity against a 25 kDa staphylococcal protein was significantly associated with peritonitis.     

Chronic mucocutaneous candidiasis. I. Altered antigen-stimulated IL-2, IL-4, IL-6 and interferon-gamma (IFN-γ) production

Patients with chronic mucocutaneous candidiasis (CMC) present with persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been documented in CMC patients, but the defect remains poorly understood. The importance of Th1 cytokines in resistance and Th2 in susceptibility to Candida infections has recently been demonstrated in murine models. In our studies we evaluated production of IL-2 and IFN-γ (markers of Th1 type responses) as well as IL-4 and IL-6 (Th2 type markers) following stimulation with two kinds of Candida antigens (CAgs), polysaccharide antigens, tetanus toxoid and pokeweed mitogen. Our results demonstrate that CMC patients have impaired cytokine production upon in vitro stimulation with CAgs resulting in low or absent IL-2, increased IL-6 and either absent or increased IFN-γ production. Cytokine production following stimulation by other antigens was unaltered. The overall cytokine-producing capacity assessed through mitogen stimulation was also intact. Addition of IFN-α or IFN-γ to culture in an attempt to modify cytokine production did not have significant effects. Levels of soluble IL-6 receptors were not increased and could not account for increased IL-6 production. Our studies support the hypothesis that Candida antigens trigger a predominantly Th2 instead of a Th1 cytokine response in patients with CMC.     

Infection peritonitis in patients undergoing continuous ambulatory peritoneal dialysis: microbiological review during an four-year period

The purpose of this study was to analyse the microbiological characteristics of infectious peritonitis in patients undergoing continuous ambulatory peritoneal dialysis. This study was conducted at the CHU Nancy from 1999 to 2002. The diagnosis of peritonitis was based on cloudy peritoneal effluent (>100 cells per mm(3)) with an elevated leukocyte count (>50%), on isolation of bacteria or fungi and on symptoms such as abdominal discomfort or pain. The majority of infections associated with continuous ambulatory peritoneal dialysis were caused by Gram-positive bacteria (68%), Gram-negative bacteria (31%), and Candida (1%). The coagulase-negative staphylococci were the most common cause of peritonitis. The antibiotic sensitivity of species corresponded to community-acquired isolation.