Phleum pratense molecular pattern across Italy.

SUMMARY: Introduction. Phleum pratense (Timothy grass) is the most frequent cause of grass allergy in Europe. Molecular-based allergy diagnostics have been recently introduced in the clinical practice, allowing to define and characterize exactly the sensitization profile. Aim of the study. The present study was aimed to investigate the possible relationships between Graminaceae pollen data and the pattern of IgE reactivity to different allergen components across Italy. Methods. Pollen data, including duration and quantity, were recorded over a 10-year period in 24 Italian centres located along the Italian peninsula. Phl p molecular patterns (Phl p 1, 5, 7, 12) were evaluated in 4 different Italian geographical areas. Results. There were significant differences about pollen count and sensitization prevalence across Italy. Different molecular patterns were defined considering the different Italian locations. Conclusion. This study demonstrates that Phleum pratense sensitization is relevant in Italy, but there are significant geographical variations variations as far as pollen exposure and pattern of IgE reactivity to the considered allergen components are concerned. This information may have clinical relevance in managing patients allergic to grass pollen.

Parietaria pollination duration: myth or fact?

Background. Even though the Parietaria pollen season may be rather long, it is commonly thought that Parietaria pollen is a perennial allergen present along the whole year. Objective. This study aimed at investigating the duration of Parietaria pollen season during a 10-year period in Italy, analysing also the annual pollen quantity and the differences among geographical areas. Methods. Pollen count was assessed daily for 10 years. Globally, ten Italian centers measured Parietaria pollen count. Start date, peak date, end date, duration (days), peak value, and seasonal pollen index were evaluated in each center. Results. Ten-year Parietaria pollen count demonstrates that the pollen season usually lasted for 6-7 months in Italy. There are important differences among centres, mainly attributable to geoclimatic factors. Conclusion. This study demonstrates that Parietaria pollen season lasts about 6-7 months with two peaks (mainly in spring and lower in autumn) in Italy with important geographical variations. This information may have clinical relevance in managing patients allergic to Parietaria.

Integrated pharmacokinetic-pharmacodynamic modelling to evaluate antimicrobial prophylaxis in abdominal surgery.

OBJECTIVES: To use Monte Carlo simulation with an integrated pharmacokinetic-pharmacodynamic (PK-PD) model to evaluate guideline-recommended antimicrobial prophylaxis (AP) regimens with anaerobic coverage in abdominal surgery. METHODS: AP regimens were tested in simulated subjects undergoing elective abdominal surgery using relevant PK models and pathogen distributions in surgical site infections (SSIs). Predicted cumulative target attainment was the percentage of simulated subjects with free (unbound) antimicrobial plasma concentrations above the MICs for potential SSI pathogens. RESULTS: Cefazolin plus metronidazole covered SSI aerobes in 70% and the Bacteroides fragilis group in 99% of subjects, whereas cefoxitin only covered aerobes and anaerobes in 63% and 27% of cases, respectively. The broad-spectrum ceftriaxone plus metronidazole covered aerobes in 82% and anaerobes in 99% of simulations, while ertapenem covered aerobes in 88% and anaerobes in 90% of cases. Clindamycin covered the B. fragilis group in only 11% of cases. For cefazolin, 2 g doses maintained target attainment in simulated subjects from 80 to 120 kg, whereas 1 g doses were associated with lower target attainment against potential Gram-negative pathogens even in those <80 kg. For gentamicin, 3 mg/kg doses were comparable to the suggested 5 mg/kg, but superior to the traditional 1.5 mg/kg. CONCLUSIONS: This study demonstrates the use of PK-PD to inform decisions regarding AP in abdominal surgery. In this case, the findings support avoiding cefoxitin, avoiding clindamycin for anaerobic coverage, selecting 2 g doses of cefazolin even in patients <80 kg and using 3 mg/kg doses of gentamicin.

Different allergenicity of pollen extracts of three Mediterranean cypress species accounted for cytological observations.

BACKGROUND: Cypresses play an important role in the urban landscape of the Mediterranean region, releasing a huge amount of allergenic airborne pollen which causes a specific pollinosis in exposed people. OBJECTIVE: The aim of this work is to evaluate, in vivo and in vitro, the potential allergenicity of Cupressus macrocarpa pollen, and to compare it with the allergenicity observed for C. arizonica and C. sempervirens. METHODS: Pollen extracts of the three species were prepared, to determine their protein profile through SDS PAGE analysis and to evaluate their allergenic potential through EAST inhibition assays and SPT. Pollen grain composition was evaluated using a cytochemical approach with optical microscopy. RESULTS: SDS PAGE, EAST inhibition and SPT indicated the higher allergenic potential of C. arizonica compared to C. sempervirens and C. macrocarpa. No significant differences in allergenic potential were found between the latter two species. Cytochemical observations reveal higher ß-glucans and protein content in the intine of C. arizonica during hydration. CONCLUSION: The higher protein content found in C. arizonica pollen grains extract may be due to higher enzyme activity leading to the movement of ß-glucans and pectins from the intine to the partially developed pollen cell wall during hydration. This could explain the higher potential allergenicity of C.arizonica in respect to C. macrocarpa and C. sempervirens.

Occupational asthma associated to the exposure to limonium tataricum flowers.

Limonium tataricum (Lt) is a plant belonging to the family of Plumbaginaceae. The role of this family and in particular, that of dried flowers (but not of the pollen) in occupational allergy has already been described. We have observed a farmer with asthma occurring in the presence of fresh flowers. Standard methacoline test demonstrated that the patient was a true asthmatic. The allergenicity of Lt pollen was thus investigated Skin prick tests (SPT) were carried out using both standard allergens and the Lt extract and the patient's mucosal reactivity was evaluated by nasal provocation test with the pollen extract. In vitro studies were also performed on the patient's serum by evaluating routine specific anti-allergen IgE on raw extracts and on Microarray Allergen Chip (ISAC). Finally, the raw extract of the fresh Lt pollen was also used in ELISA inhibition test, immunoblotting and Basophil Activation Test (BAT). The specific sensitization was demonstrated by Skin Prick test and nasal provocation test. The sensitization was also confirmed by specific IgE and by in vitro activation of basophils in the presence of the pollen. By using RAST inhibition test, the presence of cross-reactivity with other pollens was ruled out. According to our results, Lt extracts contain an allergenic activity not only as dried flowers, but also as fresh pollen. For its role in occupational asthma, this allergen should be included in any allergy screening at least in farmers or in the flower industry employers.

Shrimp allergy in Italian adults: a multicenter study showing a high prevalence of sensitivity to novel high molecular weight allergens.

BACKGROUND: Shrimp is a frequent cause of food allergy worldwide. Besides tropomyosin, several allergens have been described recently. OBJECTIVE: We investigated which allergens are involved in Italian shrimp-allergic adults. METHODS: Sera from 116 shrimp-allergic patients selected in 14 Italian allergy centers were studied. Skin prick tests with house dust mite (HDM) as well as measurements of IgE to Pen a 1 (shrimp tropomyosin) and whole shrimp extract were performed. All sera underwent shrimp immunoblot analysis, and inhibition experiments using HDM extract as inhibitor were carried out on some Pen a 1-negative sera. RESULTS: Immunoblots showed much variability. IgE reactivity at about 30 kDa (tropomyosin) was found in <50% of cases, and reactivity at about 67 kDa and >90 kDa was frequent. Further reactivities at 14-18, 25, 43-50, about 60 and about 80 kDa were detected. Most subjects had a history of shrimp-induced systemic symptoms irrespective of the relevant allergen protein. IgE to Pen a 1 were detected in sera from 46 (41%) patients. Skin reactivity to HDM was found in 43/61 (70%) Pen 1-negative subjects and inhibition studies showed that pre-adsorption of sera with HDM extract induced a marked weakening of the signal at >67 kDa. CONCLUSIONS: Several allergens other than tropomyosin are involved in shrimp allergy in adult Italian patients. Some hitherto not described high molecular weight allergens seem particularly relevant in this population and their cross-reactivity with HDM allergens makes them novel potential panallergens of invertebrates.

Late onset asthma in the elderly and its relationship with atopy.

Although asthma has always been considered as a disease of the early years, its presence is found both in old and young people. Asthma is often underestimated in the elderly because it can be confused with other diseases such as heart failure and, frequently, with COPD. In most cases asthmatic patients develop their disease before 45 years of age, but sometimes the first episode of asthma occurs after 60 years of age. This asthma phenotype is called Late Onset Asthma (LOA). LOA is often underestimated but, in recent years, some studies have shown that LOA is not entirely uncommon among the elderly; this clinical form is often caused by allergic sensitizations. The cause depends on the overall improvement of health in the most economically developed nations and also on the parallel increase in allergic diseases in these countries.

Cypress pollen does not cross-react to plant-derived foods.

BACKGROUND AND OBJECTIVE: Some studies hypothesize the existence of cross-reactivity between allergy to Cupressus sempervirens pollen and plant-derived foods. We aimed to assess whether this holds true. METHODS: 72 patients monosensitized to cypress pollen were investigated for food allergy to peach, apple, tomato and Juniperius oxycedrus berry. RESULTS: No patient had a history of clinical allergy or showed in-vitro or in-vitro reactivity to peach, apple, and tomato. Two patients scored positive on SPT with Juniperius oxycedrus berry but in-vitro tests ruled out cross-reactivity with the corresponding pollen. CONCLUSION: Airborne allergy to Cupressaceae pollen is not associated with allergy to plant-derived foods.

Economic aspects of sublingual immunotherapy.

Allergic rhinitis and asthma have a very high prevalence and constitute a health problem with a relevant burden of disease, concerning medical and economical issues. Among the treatments of allergy, specific immunotherapy (IT) has the capacity to favourably alter the natural history of the disease both during and after its performance, and thus to reduce the direct and indirect costs of allergic rhinitis and asthma. A number of studies reported a cost reduction for traditional, subcutaneous IT (SCIT). We analyzed the available studies on economic evaluation of sublingual immunotherapy (SLIT) in children and adults. Articles were retrieved from Medline and Embase using the terms economic aspects, pharmacoeconomics, cost effectiveness, and sublingual immunotherapy. 18 articles were found in English language, 7 studies investigated the economic advantage of SLIT over standard drug treatment in subjects with respiratory allergy, and 2 of them included a comparison of costs of SCIT and SLIT. The data obtained provide evidence that SLIT is associated to economic advantages and/or monetary savings, specifically in terms of reduction of economic burden of the disease. Although the number of studies is still limited, the available data support a SLIT effect on sparing costs for respiratory allergy.

Characteristics of patients with allergic polysensitization: the POLISMAIL study.

BACKGROUND: The natural history of respiratory allergy is commonly characterized by a worsening of symptom severity, frequent comorbidity of rhinitis and asthma, and polysensitization to aeroallergens. The polysensitization phenomenon starts since childhood and is rare to find monosensitized adult patients. However, there are few studies investigating the characteristics of polysensitized patients. METHODS: This study was performed on a large cohort of patients with allergic rhinitis (assessed by ARIA criteria) and/or mild to moderate asthma (assessed by GINA). The kind and the number of sensitizations, their patterns, and the relation with quality of life (QoL) measured by the Juniper's RQLQ guestionnaire, were evaluated. RESULTS: Globally 418 patients (50.2% males, 49.8% females, mean age 26.4 years, range 3.5-65 years, 64 smokers, 371 non-smokers) were enrolled: 220 had allergic rhinitis alone, and 198 allergic rhinitis and asthma. The mean number ofsensitizations was 2.6. Three hundred-five patients (73%) had persistent rhinitis (PER), 220 of them with moderate-severe form. There was no significant derence in rate of rhinitis and asthma in monosensitized or polysensitized patients. Most patients were sensitized to pollens, whereas only 24.2% of them were sensitized to perennial allergens. Polysensitization was significantly associated with some issues of QoL, confirming previous findings, but not with number ofsensitizations. CONCLUSIONS: This study provides data confirming for poly-sensitized patients the relevance of ARIA classification of AR. PER is the most common form of AR in this cohort, symptoms are frequently moderate-severe, and asthma is present in about the half of patients with AR.

The role of health technology assessment in the comprehensive evaluation of the impact of immunotherapy on real practice.

The increasing development of new health care technologies, along with the ageing of the population and the increasing patients' expectations, cause a significant raise in medical costs, inducing in policy makers the need for well-funded information to support their decisions. The development of Health Technology Assessment (HTA), which is the systematic evaluation of properties, effects or other impacts of health technology and can be considered as a bridge between the world of research and the world of policy-making, reflects this high level of demand. HTA requires a multidisciplinary approach, that covers many different disciplines, in order to assess various aspects of health technologies, as technical properties, safety, efficacy/effectiveness, economic aspects, social, legal, ethical and political impacts. Allergic diseases show a worldwide increasing prevalence and consequent increasing costs, which result very high in recent evaluations. Specific immunotherapy is the only treatment able to alter, differently from drugs, the natural course of allergic diseases, exerting a long-lasting therapeutic effect, that persists also after stopping the therapy. This has a potential great impact in the cost of disease, which only recently was considered in properly designed studies. These issues claim for a larger use of HTA, which may provide a more comprehensive approach to the evaluation of the impact of immunotherapy on allergic patients.

Pharmacoeconomics of subcutaneous allergen immunotherapy.

The current burden of allergic diseases, estimated by both direct and indirect costs, is very relevant. In fact the cost estimation for rhinitis amount globally to 4-10 billion dollars/year in the U.S. and to an average annual cost of 1089 euros per child/adolescent and 1543 euros per adult in Europe. The estimated annual costs in Northern America for asthma amounted to 14 billion dollars. Consequently, preventive strategies aimed at reducing the clinical severity of allergy are potentially able to reduce its costs. Among them, specific immunotherapy (SIT) joins to the preventive capacity the carryover effect once treatment is discontinued. A number of studies, mainly conducted in the US and Germany demonstrated a favourable cost-benefit balance. In the nineties, most surveys on patients with allergic rhinitis and asthma reported significant reductions of the direct and indirect costs in subjects treated with SIT compared to those treated with symptomatic drugs. This is fully confirmed in recent studies conducted in European countries: in Denmark the direct cost per patient/year of the standard care was more than halved following SIT; in Italy a study on Parietaria allergic patients demonstrated a significant difference in favor of SIT plus drug treatment for three years versus drug treatment alone, with a cost reduction starting from the 2nd year and increasing to 48% at the 3rd year, with a highly statistical significance which was maintained up to the 6th year, i.e. 3 years after stopping immunotherapy, corresponding to a net saving for each patient at the final evaluation of 623 euros per year; in France a cost/efficacy analysis comparing SIT and current symptomatic treatment in adults and children with dust mite and pollen allergy showed remarkable savings with SIT for both allergies in adults and children.

Economic evaluation of sublingual immunotherapy: an analysis of literature.

Allergic rhinitis and asthma constitute a global health problem because of their very high prevalence and the consequent burden of disease, concerning medical and economical issues. Among the treatments of allergy, specific immunotherapy has the capacity to favourably alter the natural history of the disease both during and after its performance and thus to reduce the direct and indirect costs of allergic rhinitis and asthma. A number of studies reported such cost reduction for traditional, subcutaneous immunotherapy and recent data demonstrate that also sublingual immunotherapy (SLIT) is associated to economic advantages and/or monetary savings, specifically in terms of reduction of disease economic burden. Only few formal economic assessments of SLIT have been carried out so far, this article will present and discuss the published studies addressed to this issue. The data obtained, although the number of studies is still limited, provide preliminary evidence supporting a SLIT effect on sparing costs for respiratory allergy.

In vitro and in vivo biological activities of old and fresh Cupressus arizonica pollen.

BACKGROUND: Respiratory allergy to the pollen of Cupressaceae is becoming more and more common every year in the Mediterranean area. OBJECTIVE: The purpose of this study was to see whether the allergenic potency of Cupressus arizonica pollen diminished after a 6-year period (1994-2000). MATERIALS AND METHODS: Among the Cupressaceae, we selected the pollen of C arizonica. The mode of sampling in 1994 and in 2000 was the same and the pollen was collected on the same tree and stored at room temperature. To compare its biological and allergenic activities data was collected with the following methods: cytohistology of Alexander, 2,3,5-triphenyltetrazolium chloride enzyme staining, skin testing, nasal provocation test, radioallergosorbent test (RAST), RAST inhibition, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and immunoblotting to detect protein content. Thirty-eight patients with respiratory allergy to Cupressaceae were selected. RESULTS: We found no decrease in the allergenic potency of the pollen, but did find that viability and germinating power had disappeared completely after 30 to 40 days. Moreover, the amount of protein in the old pollen was half the amount found in the fresh one. Skin prick testing showed identical results with the old and the fresh pollens. CONCLUSIONS: The allergenic in vivo and in vitro activity of cypress pollen is retained for years after its collection. This activity seems to be independent of the viability of pollen grains and of the total protein content. This may explain the presence of clinical symptoms in patients out of the pollen season.

Occupational respiratory allergy to cyclamen pollen: a case report.

A case of cyclamen (Cyclamen persicum) pollen allergy is described on a flower cultivator. The diagnosis was assessed by skin test, methacoline test, nasal provocation test and RAST. SDS-PAGE and immunoblotting have shown an intense response against a 18 kDa component and a weaker one at 100 Kda. A RAST inhibition against Cupressus sempervirens and Acacia floribundia showed no identity with cyclamen. This case confirm the cyclamen allergenity, in professional exposure. The nasal challenge prove to be very useful to confirm allergic sensitizations an we emphasize the necessity of preventive measures of protection for those florists who cultivate cyclamen plants.

Practice parameters for sublingual immunotherapy.

The efficacy and safety of sublingual immunotherapy (SLIT) are currently supported by clinical trials, meta-analysis and post-marketing surveys. Practice parameters for clinical use of SLIT are proposed here by a panel of Italian specialists, with reference to evidence based criteria. Indications to SLIT include allergic rhinoconjunctivitis, asthma, and isolated conjunctivitis (strength of recommendation: grade A). As to severity of the disease, SLIT is indicated in moderate/severe intermittent rhinitis, persistent rhinitis and mild to moderate asthma (grade D). SLIT may be safely prescribed also in children aged three to five years (grade B), and its use in subjects aged more than 60 years is not prevented when the indications and contraindication are ascertained (grade D). The choice of the allergen to be employed for SLIT should be made in accordance with the combination of clinical history and results of skin prick tests (grade D). Polysensitisation, i.e. the occurrence of multiple positive response does not exclude SLIT, which may be done with the clinically most important allergens (grade D). As to practical administration, co-seasonal, pre co-seasonal, and continuous schedules are available, being the latter recommended for perennial allergens or for pollens with particularly prolonged pollination, such as Parietaria (grade D). For pollens with relatively short pollination, such as grasses and trees (cypress, birch, alder, hazelnut, olive) the pre co-seasonal and perennial schedules are preferred (grade C). The build-up phases suggested by manufacturers can be safely used (grade A), but they can be modified according to the patient's tolerance (grade C). A duration of SLIT of 3-5 years is recommended to ensure a long-lasting clinical effect after the treatment has been terminated (grade C).

Targeted benefits of prolonged-infusion piperacillin-tazobactam in an in vitro infection model of Pseudomonas aeruginosa.

Given the inconsistent clinical findings, our goal was to characterize the pharmacodynamics (PDs) of prolonged-infusion piperacillin-tazobactam (TZP) in an in vitro pharmacodynamic model of Pseudomonas aeruginosa. Specifically, the study was designed to investigate the influence of MIC on the activity of prolonged-infusion TZP using pharmacokinetics (PKs) consistent with a non-critically ill patient population. There was no benefit with prolonged- compared with standard-infusion TZP against isolates with susceptible MICs of 8 or 16 mg/L. However, prolonged-infusion TZP produced more than two times the final bacterial kill against less susceptible isolates with an intermediate MIC of 32 mg/L. The PDs of TZP were well described by a sigmoid Emax model (r(2) = 0.84) where %ƒT>MIC thresholds of 27 and 75% were associated with bacteriostatic and bactericidal effects, respectively. However, the well-established PD relationship with %ƒT>MIC was not observed with prolonged-infusion TZP. In conclusion, this study characterizes the targeted benefits of prolong-infusion TZP based on pathogen MIC, and supports the assertion that the benefits are selective and most likely observed in patients with less susceptible pathogens or altered PKs.

Efficacy of sublingual coseasonal immunotherapy with a monomeric allergoid in Cupressaceae pollen allergy--preliminary data.

BACKGROUND: Respiratory allergy to conifers pollens is a growing phenomenon all over the world (Mediterranean area, USA, Japan). In France and Italy Cupressus sempervirens is the commonest offender. OBJECTIVE: To check the efficacy of specific immunotherapy by the sublingual route using a monomeric allergoid of Cupressus Arizonica pollen. MATERIAL AND METHODS: 20 patients and 10 controls were randomly selected. The diagnosis was assessed on a clinical hivernal symptomatology of allergic rhinitis, and/or asthma, positive skin test and RAST, and nasal provocation test to Cupressus arizonica. The extract was a monomeric allergoid titrated in allergenic units (AU). The treatment was coseasonal from the beginning of december to the end of march. It was not conducted double blind. RESULTS: The evaluation of the allergenic potency of native and modified Cupressus arizonica extracts have shown that the modified extract has a decreased skin test IgE binding capacity. According to symptom, drug consumption scores and nasal provocation test, there was a statistical improvement in the active group (compared to the control group) without any side effect. DISCUSSION: The use of a modified Cupressus arizonica extract, which is easier to prepare than Cupressus sempervirens and which is a monomeric allergoid, has shown that by the sublingual route, this therapeutic approach is safe and that the first results were satisfactory without any side effect. This good tolerance was anticipated by the fact that, checked on 16 volunteers by skin test, the allergoid gave a less important local reaction on skin testing than the native extract. CONCLUSION: This study has shown that: The KCNO modified Cupressus arizonica extract has a reduced IgE binding capacity; This monomeric allergoid is safe and effective administrated by the oromucosal route in clinical respiratory allergy to Cupressaceae and devoid of any side effect.

HLA-DRB1* and allergy to Parietaria: linkage and association analyses.

In this study, we used the affected sibling-pairs approach to investigate the linkage of HLA (human leukocyte antigen)-DRB* with phenotypes related to allergy to Parietaria, the most common pollinosis in Mediterranean countries. The study population consisted of 51 nuclear families (235 subjects). Linkage was detected with Parietaria skin test positivity (p < (0.01), presence of IgG and IgE antibodies specific for the major allergen Par o 1 (p < 0.020 and p < 0.025, respectively), and absence of Par o 1-specific IgE (p < 0.020). High levels of Par o 1-specific IgG were associated with DRB1*1101 and/or DRB1*1104 (p < 0.0001 and p < 0.0119, respectively) in parents and probands. High levels of Par o 1-specific IgE were associated with DRB*1104 in parents (p < 0.017) and with DRB1*1101 in probands (p < 0.0146). When siblings were categorized according to high/low total IgE levels (> or =125 IU/ml and <125 IU/ml, respectively), high IgE antibody response was associated with DRB1*1104 in siblings with low total IgE (p < 0.034) and with DRB1*1101 in siblings with high total IgE (p < 0.05). These results demonstrate that HLA-DRB1*, or genes in linkage disequilibrium, contributes to susceptibility to Parietaria allergy and that total IgE levels can discriminate population subsets where different alleles (at the HLA region or at loci in linkage disequilibrium) contribute to control allergen-specific IgE synthesis.

Analysis of microbiological trends in peritoneal dialysis-related peritonitis from 1991 to 1998.

The microbial cause of peritoneal dialysis-related peritonitis is an important determinant of clinical outcome and the basis of widely used treatment guidelines. Five hundred forty-six cases of peritonitis in 374 patients from 1991 to 1998 were analyzed. The rate of peritonitis declined significantly from 1.37 episodes/patient-year in 1991 to 0.55 episode/patient-year in 1998 (P = 0.02). The rate of Gram-positive peritonitis decreased significantly from 0.75 to 0.28 episode/patient-year during the same period (P = 0.02). Conversely, the occurrence of Gram-negative peritonitis remained constant at approximately 0.16 episode/patient-year (P = 0.28). Staphylococcus epidermidis and Staphylococcus aureus were the most common causes of peritonitis, isolated in 27.8% and 19.3% of the culture-positive cases, respectively. A distinct decrease in peritonitis caused by S epidermidis was observed, with 0.40 episode/patient-year in 1991 compared with 0.11 to 0.20 episode/patient-year during subsequent years. The rate of infections caused by S aureus decreased significantly over time from a high of 0.21 episode/patient-year in 1992 to a low of 0.04 episode/patient-year in 1998 (P = 0.01). Pseudomonas aeruginosa, Escherichia coli, and KLEBSIELLA: species were the most common causes of Gram-negative peritonitis, identified in 7.1%, 6.8%, and 5.2% of culture-positive cases, respectively. The most dramatic increase in antibiotic resistance was seen among S epidermidis. From 1991 and 1992 to 1997 and 1998, resistance to ciprofloxacin increased from 5.4% to 47.8% (P = 0.003), and resistance to methicillin increased from 18.9% to 73.9% (P = 0.03). Our study showed significant trends in the causative pathogens of peritoneal dialysis-related peritonitis and dramatic increases in antibiotic resistance. These data support further study and warrant reevaluation of current treatment practices.