Laboratory handling practice for faecal microbiota transplantation.

AIMS: Faecal microbiota transplantation (FMT) consists of the infusion of faeces from a healthy donor to the gastrointestinal tract of a recipient patient to treat disease associated with alterations in gut microbiota. The objective of this article was to describe laboratory workflow of an FMT laboratory to provide tips for preparing the faecal suspensions to be infused. METHODS AND RESULTS: Twenty-stool solutions obtained from ten donors were prepared using two different protocols: magnet plate emulsion (MPE) and Seward StomacherTM Emulsion (SSE). We evaluated parameters such as preparation time, handiness, and aerobic and anaerobic microbial count. For three donors, we monitored bacterial counts after defrosting at different time-points. MPE requires more time than SSE. In terms of microbial load, both methods showed similar values, with small and statistically differences (P ≤ 0·05) regarding anaerobes in favour of SSE. Frozen aliquots showed the same bacterial load values after defrosting. CONCLUSION: Although both methods allow an easy and available preparation of a stool suspension, SSE seems more suitable, particularly for stool banking. Aerobic and anaerobic species are preserved with both protocols; and safety for laboratory operators is guaranteed. SIGNIFICANCE AND IMPACT OF THE STUDY: In recent years, FMT has become a fascinating and interesting subject. Nevertheless, there are no real guidelines describing laboratory facilities and procedures. This paper aims to be a useful and simple guide to increase the number FMT centres as much possible.

Nickel free-diet enhances the Helicobacter pylori eradication rate: a pilot study.

BACKGROUND: The Helicobacter pylori eradication rate with standard triple therapy is very low. H. pylori is known to require the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive at the low pH environment in the stomach. AIM: To compare the H. pylori eradication rate of a nickel free-diet associated with standard triple therapy and standard triple therapy alone as the first-line regimen. METHODS: Fifty-two sex- and age-matched patients at the first diagnosis of H. pylori infection were randomized 1:1 into two different therapeutic schemes: (1) standard LCA (26 patients): lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid for 7 days with a common diet; (2) standard LCA plus a nickel free-diet (NFD-LCA) (26 patients). Patients followed 30 days of a nickel-free diet plus a week of lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid starting from day 15 of the diet. RESULTS: All patients completed the study. A significantly higher eradication rate was observed in the NFD-LCA group (22/26) versus LCA group (12/26) (p < 0.01). Only a few patients (9 of 52) reported the occurrence of mild therapy-related side effects, without any significant differences between the two groups. CONCLUSIONS: The addition of a nickel-free diet to standard triple therapy significantly increases the H. pylori eradication rate. The reduction of H. pylori urease activity due to the nickel-free diet could expose the bacterium to gastric acid and increase H. pylori's susceptibility to amoxicillin. Further studies are necessary to confirm this preliminary result.

High-dose rocuronium for rapid-sequence induction and reversal with sugammadex in two myasthenic patients.

The anesthetic management of patients affected by myasthenia gravis is usually challenging in elective surgery and even more so in emergency procedures. The difficulties involved are several-fold, ranging from the choice of an appropriate muscle relaxant (i.e. one that enables safe and rapid airway management) to neuromuscular monitoring and normal muscular recovery. Additionally, optimizing patient conditions - either pharmacologically or with plasmapheresis - before intervention is well beyond the realm of possibility. We discuss the anesthetic management of two myasthenic patients undergoing emergency surgery (for sigmoid perforation and upper gastrointestinal bleeding respectively). In both cases, we opted for rapid-sequence induction with high-dose rocuronium to prevent inhalation of gastric contents. We also report on the implication of neuromuscular monitoring. We found that the rocuronium-sugammadex combination was a useful and effective option in the emergency setting.

Development of clinical tools to estimate the breathing effort during high-flow oxygen therapy: A multicenter cohort study.

INTRODUCTION AND OBJECTIVES: Quantifying breathing effort in non-intubated patients is important but difficult. We aimed to develop two models to estimate it in patients treated with high-flow oxygen therapy. PATIENTS AND METHODS: We analyzed the data of 260 patients from previous studies who received high-flow oxygen therapy. Their breathing effort was measured as the maximal deflection of esophageal pressure (ΔPes). We developed a multivariable linear regression model to estimate ΔPes (in cmH2O) and a multivariable logistic regression model to predict the risk of ΔPes being >10 cmH2O. Candidate predictors included age, sex, diagnosis of the coronavirus disease 2019 (COVID-19), respiratory rate, heart rate, mean arterial pressure, the results of arterial blood gas analysis, including base excess concentration (BEa) and the ratio of arterial tension to the inspiratory fraction of oxygen (PaO2:FiO2), and the product term between COVID-19 and PaO2:FiO2. RESULTS: We found that ΔPes can be estimated from the presence or absence of COVID-19, BEa, respiratory rate, PaO2:FiO2, and the product term between COVID-19 and PaO2:FiO2. The adjusted R2 was 0.39. The risk of ΔPes being >10 cmH2O can be predicted from BEa, respiratory rate, and PaO2:FiO2. The area under the receiver operating characteristic curve was 0.79 (0.73-0.85). We called these two models BREF, where BREF stands for BReathing EFfort and the three common predictors: BEa (B), respiratory rate (RE), and PaO2:FiO2 (F). CONCLUSIONS: We developed two models to estimate the breathing effort of patients on high-flow oxygen therapy. Our initial findings are promising and suggest that these models merit further evaluation.

A 1-year follow-up study on checkpoint inhibitor-induced colitis: results from a European consortium.

BACKGROUND: Data regarding the clinical outcome of patients with immune checkpoint inhibitor (ICI)-induced colitis are scant. We aimed to describe the 12-month clinical outcome of patients with ICI-induced colitis. MATERIALS AND METHODS: This was a retrospective, European, multicentre study. Endoscopy/histology-proven ICI-induced colitis patients were enrolled. The 12-month clinical remission rate, defined as a Common Terminology Criteria for Adverse Events diarrhoea grade of 0-1, and the correlates of 12-month remission were assessed. RESULTS: Ninety-six patients [male:female ratio 1.5:1; median age 65 years, interquartile range (IQR) 55.5-71.5 years] were included. Lung cancer (41, 42.7%) and melanoma (30, 31.2%) were the most common cancers. ICI-related gastrointestinal symptoms occurred at a median time of 4 months (IQR 2-7 months). An inflammatory bowel disease (IBD)-like pattern was present in 74 patients (77.1%) [35 (47.3%) ulcerative colitis (UC)-like, 11 (14.9%) Crohn's disease (CD)-like, 28 (37.8%) IBD-like unclassified], while microscopic colitis was present in 19 patients (19.8%). As a first line, systemic steroids were the most prescribed drugs (65, 67.7%). The 12-month clinical remission rate was 47.7 per 100 person-years [95% confidence interval (CI) 33.5-67.8). ICI was discontinued due to colitis in 66 patients (79.5%). A CD-like pattern was associated with remission failure (hazard ratio 3.84, 95% CI 1.16-12.69). Having histopathological signs of microscopic colitis (P = 0.049) and microscopic versus UC-/CD-like colitis (P = 0.014) were associated with a better outcome. Discontinuing the ICI was not related to the 12-month remission (P = 0.483). Four patients (3.1%) died from ICI-induced colitis. CONCLUSIONS: Patients with IBD-like colitis may need an early and more aggressive treatment. Future studies should focus on how to improve long-term clinical outcomes.

Pre- and posttherapy assessment of intestinal soluble mediators in IBD: where we stand and future perspectives.

Inflammatory bowel disease (IBD) is a chronic inflammatory condition characterized by an abnormal immune response against food or bacterial antigens in genetically predisposed individuals. Several factors of innate and adaptive immune system take part in the inflammatory process, probably actively contributing in endoscopic and histological healing at molecular level. Although it is difficult to discriminate whether they are primary factors in determining these events or they are secondarily involved, it would be interesting to have a clear map of those factors in order to have a restricted number of potentially "good candidates" for mucosal healing. The present review will present a class of these factors and their modulation in course of therapy, starting from pathogenic studies involving several treatments associated with good clinical outcomes. This approach is meant to help in the difficult task of identifying "good candidates" for healing signatures, which could also be possible new therapeutic targets for clinical management of IBD patients.

New insights on the role of T cells in the pathogenesis of celiac disease.

Despite intense investigation, the pathogenetic mechanisms leading to villous atrophy in Celiac disease (CD) remain not completely understood. The traditional interpretation is that CD4 cells recognize gliadin and develop an inflammatory reaction by production of Th1 cytokines at the mucosa level inducing CD8 cells to kill mucosal cells by a direct cytotoxic mechanism or by Fas-mediated apoptosis. Recent data, however, have shown that novel CD4 T-cells subpopulations, CD4+ CD25+ Regulatory T cells (Tregs) and Th17 cells also play a role in the ongoing inflammatory process. Both Tregs and Th17 cells are increased in active CD. However, because Tregs have a suppressive activity on inflammation, their role is controversial. In this editorial we discuss these recent findings and the hypothesis formulated to explain the increase of Tregs. To understand the pathogenesis of tissue damage of CD, we have focused on the duodenal micro-environment, introducing the new concept of immunological niche that in CD summarizes cellular and cytokine interactions in duodenal mucosa, where a high plasticity of T-cell subsets is present. CD is often complicated by T-cell lymphomas, especially in cases of refractory CD.

Predictors of intubation in COVID-19 patients treated with out-of-ICU continuous positive airway pressure.

BACKGROUND: As delayed intubation may worsen the outcome of coronavirus disease 2019 (COVID-19) patients treated with continuous positive airway pressure (CPAP), we sought to determine COVID-specific early predictors of CPAP failure. METHODS: In this observational retrospective multicentre study, we included all COVID-19 patients treated with out-of-ICU CPAP, candidates for intubation in case of CPAP failure. From these patients, we collected demographic and clinical data. RESULTS: A total of 397 COVID-19 patients were treated with CPAP for respiratory failure, with the therapeutic goal of providing intubation in case of CPAP failure. Univariable analysis showed that, age, lactate dehydrogenase (LDH) and white cell counts were all significantly lower in patients with successful CPAP treatment compared to those failing it and undergoing subsequent intubation. The percentage changes between baseline and CPAP application in the ratio of partial pressure arterial oxygen (PaO2) and fraction of inspired oxygen (FiO2), PaO2, respiratory rate and ROX index were higher in patients experiencing successful CPAP compared to those failing it. FiO2 and male gender were also significantly associated with intubation. Multivariable analysis adjusting for age, gender, Charlson comorbidity index, percentage change in PaO2/FiO2 or PaO2 and FiO2 separately, lactate, white blood cell count, LDH and C-reactive protein levels led to an area under the curve of 0.818 and confirmed that age, LDH and percentage increase in PaO2/FiO2 are predictors of intubation. CONCLUSIONS: In COVID-19 patients requiring CPAP, age, LDH and percentage change in PaO2/FiO2 after starting CPAP are predictors of intubation.

Lactose intolerance in systemic nickel allergy syndrome.

Some patients affected by nickel-contact allergy present digestive symptoms in addition to systemic cutaneous manifestations, falling under the condition known as systemic nickel allergy syndrome (SNAS). A nickel-related pro-inflammatory status has been documented at intestinal mucosal level. The aim of the present study is to evaluate the prevalence of lactose intolerance in patients affected by SNAS compared to a healthy population. Consecutive patients affected by SNAS referring to our departments were enrolled. The control population consisted of healthy subjects without gastrointestinal symptoms. All subjects enrolled underwent lactose breath test under standard conditions. One hundred and seventy-eight SNAS patients and 60 healthy controls were enrolled. Positivity of lactose breath test occurred in 74.7% of the SNAS group compared to 6.6% of the control group. Lactose intolerance is highly prevalent in our series of patients affected by SNAS. Based on our preliminary results, we can hypothesize that in SNAS patients, the nickel-induced pro-inflammatory status could temporarily impair the brush border enzymatic functions, resulting in hypolactasia. Further trials evaluating the effect of a nickel-low diet regimen on lactase activity, histological features and immunological pattern are needed.

How to define a quadruple aim framework to assess value in critical pathway of the patients with Clostridioides difficile infection.

OBJECTIVE: The study aims to define the set of Key Performance Indicators (KPIs) required to assess the Value delivered by managing patients with Clostridioides difficile infection through a Critical Pathway. We used the quadruple aim Value-Based approach, and we validated the set of KPIs with the Delphi method. MATERIALS AND METHODS: The study focuses on patients on board a Critical Pathway on Clostridioides difficile Infection and targeted towards a Fecal Microbiota Transplantation (FMT). FMT has been used to successfully treat recurrent Clostridium difficile infection. A two-round e-Delphi survey collecting data was conducted in 2019-2020 to validate the Value-Based evaluation tool. The Value-Based criteria taken into account are Clinical Outcomes, Experience of Care, Per-capita cost, Physician's burnout. RESULTS: The two rounds led to the validation of 50 items, and four primary clinical outcomes (Mortality rate, length of stay, readmission and complications related to the illness). CONCLUSIONS: The evaluation tool included is validated in its totality and can provide a comprehensive overview of the Value created by the Critical pathway for patients with Clostridioides difficile. We can extend the approach illustrated in this study can also to evaluate other Critical pathways.

COVID-19 in celiac disease: a multicentric retrospective cohort study.

OBJECTIVE: Celiac disease (CD) is an autoimmune disorder, characterized by increased susceptibility to bacterial and viral infections. Therefore, the CD patients could be exposed to an increased risk of contracting SARS-CoV-2, a virus for which the WHO declared a pandemic status in March 2020. This study aims to investigate the incidence of SARS-CoV-2 infection in CD patients, to assess the impact of CD on the risk of contracting this virus. PATIENTS AND METHODS: This retrospective multicentric cohort study evaluated 542 celiac patients, who answered a questionnaire concerning both the underlying disease (adherence to the gluten-free diet, residual symptoms) and the possible SARS-CoV-2 infection (swab outcome, presence and characteristics of symptoms and type of treatment received), referring to the period between 20th January 2020 and 27th October 2020. RESULTS: Five patients (0.92%) tested positive; of these, 2 were asymptomatic and 3 developed symptoms of COVID-19. The incidence of SARS-CoV-2 infection in CD patients was not significantly different from the general population. The ratio of positive/diagnostic swabs tends to be higher in CD patients than in the general population (IR: 0.15; 0.06; p=0.06), whereas the number of subjects who performed the swab in this group is significantly lower (IR: 0.06; 0.15; p<0.001). CONCLUSIONS: Although CD patients are more susceptible to infections, the incidence of SARS-CoV-2 infection in our sample was not significantly different from the general population. However, the positive/diagnostic swabs ratio seems to be higher, probably also due to the lower number of patients tested.

Changes in admissions, and hospitalization outcomes of IBD patients in an Italian tertiary referral center over a 13-year period.

OBJECTIVE: The management of Inflammatory Bowel Disease (IBD) has changed significantly in recent years, mainly due to the introduction of biologic medications, however, other factors may also have a role. The aim of this study was to evaluate the evolution of IBD admissions, including trends, modality of admission and rates of surgical intervention, in a tertiary care center. PATIENTS AND METHODS: Hospitalization of patients with a diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were identified between 2000 and 2013, using ICD-9-CM codes for IBD, from our hospital database. The following parameters were evaluated for each admission: type of admission (ordinary vs. day care service), mode of admission (elective vs. emergency care, for ordinary admissions only), admission code, surgical procedures and complication rates. Comparison between pre- and post-biologic therapy introduction years was also performed. RESULTS: Between 2000 and 2013 a total of 8834 IBD-related admissions were recorded. Hospitalizations increased linearly reaching a peak in 2006, with a downward trend in the following years. The downward trend was especially marked for patients younger than 40 years. No significant differences in hospitalization trends between CD and UC were recorded. Disease flare represented the cause of hospitalization in approximately 50% of cases. Overall, 10.8% of patients underwent surgery with no difference between the two conditions. Complications occurred in 28.7% of admissions. CONCLUSIONS: Hospitalizations for IBD patients have decreased in recent years, especially in younger patients. However, a significant proportion of patients are still admitted to complete diagnostic workup, indicating the need to better implement outpatient services. A clear reduction in surgery occurrence over time could not be observed in our study.

Increased Faecalibacterium abundance is associated with clinical improvement in patients receiving rifaximin treatment.

Compositional and functional alterations of the gut microbiota are involved in the pathogenesis of several gastrointestinal diseases. Rifaximin is often used to induce disease remission due to its eubiotic effects on the gut microbiota. To investigate the correlation between changes in the gut microbiota composition and symptoms improvement in patients who present a clinical response to rifaximin treatment. Patients with ulcerative colitis (UC), Crohn's disease (CD), irritable bowel syndrome (IBS) and diverticular disease (DD) undergoing rifaximin treatment for clinical indication were enrolled in the study. Rifaximin was administered at the dose of 1,200 mg/day for 10 days. Faecal samples were collected at baseline and at the end of treatment; clinical improvement was assessed by Mayo score for UC, CD Activity Index (CDAI) for CD, IBS severity scoring system (IBS-SSS) for IBS and global symptomatic score (GSS) for DD. Twenty-five patients were included in the analysis and a clinical improvement was recorded for 10/25 (40%) of them. Microbial alpha diversity showed a slight increase in clinical responders (P=0.271), while it decreased in patients who did not improved (P=0.05). A significant post-treatment increase in Faecalibacterium abundance was observed in patients with a positive response (log2FC 1.959, P=0.042). Roseburia abundance decreased in both groups, whereas Ruminococcus decreased only in patients who clinically improved. Clinical improvement consequent to rifaximin treatment is associated with an increase in Faecalibacterium abundance. Achieving a positive shift in the gut microbiota composition seems a key event to obtain a clinical benefit from treatment.

T-bet and pSTAT-1 expression in PBMC from coeliac disease patients: new markers of disease activity.

Coeliac disease (CD) is considered a T cell-mediated autoimmune disease, and up-regulation of T-bet and phosphorylated signal transducers and activators of transcription (pSTAT)1, key transcription factors for the development of T helper type 1 (Th1) cells, has been described in the mucosa of patients with untreated CD. Using transcription factor analysis, we investigated whether T-bet and pSTAT1 expressions are up-regulated in the peripheral blood of CD patients and correlate with disease activity. Using flow cytometry, we analysed T-bet, pSTAT1 and pSTAT3 expression in CD4(+), CD8(+) T cells, CD19(+) B cells and monocytes from peripheral blood of 15 untreated and 15 treated CD patients and 30 controls, and longitudinally in five coeliac patients before and after dietary treatment. We evaluated using enzyme-linked immunosorbent assay (ELISA), interferon (FN)-gamma, interleukin (IL)-17 and IL-10 production by peripheral blood mononuclear cell (PBMC) cultures. T-bet expression in CD4(+), CD8(+) T cells, CD19(+) B cells and monocytes and IFN-gamma production by PBMC was higher in untreated than in treated CD patients and controls. pSTAT1 expression was higher in CD4(+)T cells, B cells and monocytes from untreated than from treated CD patients and controls. pSTAT3 was increased only in monocytes from untreated patients compared with CD-treated patients and controls. The data obtained from the longitudinal evaluation of transcription factors confirmed these results. Flow cytometric analysis of pSTAT1 and T-bet protein expression in peripheral blood mononuclear cells could be useful and sensible markers in the follow-up of CD patients to evaluate disease activity and response to dietary treatment.

Celiac disease in the 21st century: issues of under- and over-diagnosis.

Until the 1960s celiac disease (CD) or sprue was considered a pediatric disease that was rarely diagnosed in adulthood. Thanks to greater awareness of the disease and the availability of improved diagnostic tools (above all, sophisticated endoscopic techniques and the development of reliable serological markers), the prevalence of CD in Western countries has been increasing steadily, and it is now recognized as a common disorder, even in adults. However, many cases of this disease still go undiagnosed, especially among the elderly and in patients with atypical clinical presentations (which are by no means uncommon). On the other hand, the frequency of unfounded diagnoses of CD is also on the rise. This reflects a tendency toward exclusively symptomatic diagnosis as well as the growing use of invalidated tests for CD (e.g., the cytotoxic test, the sublingual or subcutaneous provocation/neutralization test, etc.). As a result, public healthcare spending is being increased in several countries (Italy included) by the growing number of prescriptions for gluten-free diets. This editorial discusses the problems of under- and over-diagnosis of CD and provides an algorithm for management of suspected cases designed to minimize both problems with particular importance to morphologic aspects of small bowel (also in electron microscopy), in basal conditions or in gluten-free diets.

Thoracic epidural analgesia in post-thoracotomy patients: comparison of three different concentrations of levobupivacaine and sufentanil.

BACKGROUND: Relative effects of dosage, volume and concentration of local anaesthetics used for postoperative thoracic epidural analgesia are still under debate. In this randomized, prospective, double-blinded study, we evaluated the incidence of side-effects such as changes in arterial pressure, postoperative nausea, vomiting, and pruritus in patients admitted for thoracic surgery during continuous thoracic epidural infusion using levobupivacaine and sufentanil mixture in three different volumes. METHODS: We studied 150 patients who underwent thoracotomy with a thoracic epidural catheter placed between T4 and T7. The patients were randomized into three groups which received 10 mg h(-1) of levobupivacaine at three different concentrations (0.5%, 0.25%, and 0.15%), in combination with sufentanil at 2.6 microg h(-1). Haemodynamic effects, pruritus, nausea, vomiting, sensory and motor block, pain score, additional analgesic requirement, sedation, and patient satisfaction were registered immediately after the surgical operation and on the first, second, and third postoperative days. RESULTS: We did not detect any differences in the incidence of side-effects such as changes in arterial pressure, and also postoperative nausea, vomiting, and pruritus. The three groups were also similar with regard to patient characteristics, sensory and motor block, pain score, analgesic rescue dose, sedation, and patient satisfaction. CONCLUSIONS: The same dose of a mixture of levobupivacaine and sufentanil administered in three different volumes and concentrations during continuous thoracic epidural infusion for thoracotomy provided an equal incidence of adverse haemodynamic effects, nausea, vomiting, or pruritus.

Abnormal synthesis of IgA in coeliac disease and related disorders.

The pathogenesis of coeliac disease (CD) is complex. One controversial aspect is the role of IgA anti-endomysial (EMA) antibodies. Despite being the most reliable marker for CD diagnosis, its role in the pathogenesis (if any) remains obscure. The paradox is reinforced by the observation that CD is more common in IgA-deficient individuals. In this review, we discuss recent data suggesting that IgA autoantibodies may be related to aspecific dysregulation of IgA. In addition, new insights have elucidated new genes involved in IgA production and linked to CD. Allelic frequency of HS1,2 enhancer which regulates Ig synthesis is altered in CD and other IgA mediated disorders. We suggest that in CD, a T-cell mediated disease, the role of IgA anti-EMA autoantibodies remains elusive and could well be merely an epiphenomenon not directly related to pathogenic mechanisms, but rather to a state of heightened immunological responsiveness in genetically predisposed individuals.

HCV co-infection does not affect the TREC/IL-7 pathway in HIV disease.

About thymic output, little is known in HIV-HCV co-infected patients. Thymic output can be measured by T-cell receptor excision circles (TREC) present in the so called "recent thymic emigrants" (RTEs). We have analyzed, by Real time PCR, sj-TREC+ cells in 11 patients with HIV-HCV co-infection; all patients were treated with highly active antiretroviral therapy (HAART), but were naive for interferon anti-HCV treatment. The results were compared with those of 21 age-matched normal donors. These data show no reduction of sj-TREC+ cells in co-infection. In 5 co-infected patients, IL-7 plasmatic levels were also evaluated by ELISA and no difference between co-infected patients and normal controls was found. Taken together, our data, although limited by the numerosity of the sample, may suggest that HCV co-infection does not affect the TREC/IL-7 pathway in HIV disease.

Active thymopoiesis in idiopathic chronic pancreatitis.

BACKGROUND/AIMS: Cellular immunity has a pivotal role in the pathogenesis of chronic pancreatitis (CP), resulting in pancreas infiltration by T-cells. Studies on systemic immunity are few and contradictory. One study reported a decrease of naive CD45RA+ cells. The presence of naive T cells, detected as recent thymic emigrants (RTEs), is evaluated with a new molecular technique by using real-time PCR to detect the T-cell receptor excision circles (TREC). To elucidate the role of naive T-cells in the pathogenesis of CP, we investigated the percentage of sj-TREC in CP patients. PATIENTS: Thirty CP patients were studied and compared to 30 sex- and age-matched healthy volunteers. METHODS: Genomic DNA was isolated from peripheral blood mononuclear cells (PBMC) of each patient. RTEs were evaluated by measuring sj-TREC by real-time PCR. RESULTS: The mean percentage of sj-TREC+ cells present in CP was not significantly different from that of control group (0.02319% vs 0.02338%, respectively). CONCLUSION: Our data show that naive TREC+ cells are normally represented in CP. The presence of active thymopoiesis may be the underlying mechanism resulting in continuous production of T-cells, responsible of maintaining the inflammatory process.