Evaluation of changes in intestinal microbiota in Crohn's disease patients after anti-TNF alpha treatment.

Intestinal dysbiosis is key in the onset and development of Crohn's disease (CD). We evaluated the microbiota changes in CD patients before and after a six-month anti-TNF treatment, comparing these changes with the microbiota of healthy subjects. This prospective multicenter observational study involved 27 CD patients initiating anti-TNF treatment and 16 healthy individuals. Inflammatory activity was determined at baseline, 3 and 6 months, classifying patients into responders and non-responders. Fecal microbiota was analyzed by massive genomic sequencing thought 16S rRNA amplicon sequencing before and after six months of anti-TNF treatment. The CD cohort showed a decrease in genera of the class Clostridia, short-chain fatty acid producers, and an increase in the phylum Proteobacteria (p < 0.01) versus the healthy cohort. After anti-TNF treatment, the phylum Proteobacteria also increased in non-responders versus responders (13/27) (p < 0.005), with the class Clostridia increasing. In addition, alpha diversity increased in responders versus non-responders (p < 0.01), tending towards eubiosis. An association was found (p < 0.001) in the F.prausnitzii/E.coli ratio between responders and non-responders. The F/E ratio was the most accurate biomarker of anti-TNF response (area under the curve 0.87). Thus, anti-TNF treatment allows partial restoration of intestinal microbiota in responders and the F.prausnitzii/E.coli ratio can provide a reliable indicator of response to anti-TNF in CD.

B1a Lymphocytes (CD19+CD5+) Deficiency in Patients with Crohn's Disease and Its Relation with Disease Severity.

BACKGROUND/AIMS: B1a cells (CD19+CD5+) are considered elements of the innate immune system. The aim of this study was to evaluate the frequency of B1a cells in the peripheral blood of patients with Crohn's disease (CD) and its relation with disease severity. METHODS: In this prospective study, a total of 128 subjects (64 CD patients and 64 healthy controls) were studied. B1a cells in peripheral blood, CD Activity Index, and Simple Endoscopic Score of B1a cells were studied. RESULTS: A significant decrease of B1a cells in peripheral blood was observed in patients with CD versus controls (p = 0.002), especially in perforating or penetrating patterns (p = 0.017). A lower frequency of B1a cells is related to increased endoscopic severity (Spearman's Rho: -0.559, p = 0.004). The mean frequency of B1a cells in patients with pre- and post-study surgery was significantly lower than that in patients who did not undergo surgery (p = 0.050 and p = 0.026, respectively). CONCLUSIONS: The B1a cell count in peripheral blood is lower in CD patients. This decrease is directly related to the severity of the disease (penetrating or perforating, Simple Endoscopy Score and surgery complication). These results pointed to the fact that B1a cells play an important role in immune protection in CD.

Epstein-Barr virus is related with 5-aminosalicylic acid, tonsillectomy, and CD19(+) cells in Crohn's disease.

AIM: To study anti-Epstein-Barr virus (EBV) IgG antibodies in Crohn's disease in relation to treatment, immune cells, and prior tonsillectomy/appendectomy. METHODS: This study included 36 CD patients and 36 healthy individuals (controls), and evaluated different clinical scenarios (new patient, remission and active disease), previous mucosa-associated lymphoid tissue removal (tonsillectomy and appendectomy) and therapeutic regimens (5-aminosalicylic acid, azathioprine, anti-tumor necrosis factor, antibiotics, and corticosteroids). T and B cells subsets in peripheral blood were analyzed by flow cytometry (markers included: CD45, CD4, CD8, CD3, CD19, CD56, CD2, CD3, TCRαß and TCRγδ) to relate with the levels of anti-EBV IgG antibodies, determined by enzyme-linked immunosorbent assay. RESULTS: The lowest anti-EBV IgG levels were observed in the group of patients that were not in a specific treatment (95.4 ± 53.9 U/mL vs 131.5 ± 46.2 U/mL, P = 0.038). The patients that were treated with 5-aminosalicylic acid showed the highest anti-EBV IgG values (144.3 U/mL vs 102.6 U/mL, P = 0.045). CD19(+) cells had the largest decrease in the group of CD patients that received treatment (138.6 vs 223.9, P = 0.022). The analysis of anti-EBV IgG with respect to the presence or absence of tonsillectomy showed the highest values in the tonsillectomy group of CD patients (169.2 ± 20.7 U/mL vs 106.1 ± 50.3 U/mL, P = 0.002). However, in the group of healthy controls, no differences were seen between those who had been tonsillectomized and subjects who had not been operated on (134.0 ± 52.5 U/mL vs 127.7 ± 48.1 U/mL, P = 0.523). CONCLUSION: High anti-EBV IgG levels in CD are associated with 5-aminosalicylic acid treatment, tonsillectomy, and decrease of CD19(+) cells.

Microsporidia and its relation to Crohn's disease. A retrospective study.

BACKGROUND: The cause of Crohn's Disease (CD) remains unknown. Recently a decrease in the global lymphocyte population in the peripheral blood of CD patients has been reported. This decrease was more evident in γδ T lymphocytes, especially γδ CD8+T subsets. Furthermore, a decrease of IL-7 was also observed in these patients. We propose the hypothesis that microsporidia, an obligate intracellular opportunistic parasite recently related to fungi, in CD patients can take advantage of the lymphocytes and IL-7 deficits to proliferate and to contribute to the pathophysiology of this disease. METHODS AND FINDINGS: In this case-control study, serum samples were collected from 36 CD patients and from 36 healthy individuals (controls), IgE and IgG anti-Encephalitozoon antibodies were determined by ELISA; and forty-four intestinal tissue samples were analyzed through real time Polymerase Chain Reaction (PCR), twenty CD patients, nine with others diseases and 15 healthy subjects. We observed that IgE anti-Encephalitozoon levels were significantly higher in patients with CD: 0.386(±0.256) vs control group, 0.201(±0.147), P<0.001. However, IgG anti-Encephalitozoon values were significantly lower in CD patients: 0.361(±0.256) vs control group, 0.876(±0.380), P<0.001. In the group of CD patients, 6/20 (30%) were positive by real time PCR for microsporidia and, all the patients of the control group were negative by real time PCR. CONCLUSIONS: These results suggest that CD patients are a group at risk for microsporidiasis and, moreover that microsporidia may be involved as a possible etiologic factor of CD.

Deficit of gammadelta T lymphocytes in the peripheral blood of patients with Crohn's disease.

BACKGROUND: Gammadelta T lymphocytes are an important component of innate immunity. Previous studies have shown their role in the development of Crohn's-like colitis in mice. AIMS: The aim of this study was to measure the γδ T lymphocyte levels in Crohn's disease (CD) patients. METHODS: A prospective study of 40 patients with CD compared with 40 healthy subjects (control group) matched by age and sex was undertaken. Lennard-Jones criteria were used for the diagnosis of CD. Disease activity was measured with the Crohn's disease activity index (CDAI). New patients, patients in remission, and patients with active disease were evaluated. Lymphocytic populations of CD3+, CD4+, CD8+, CD56+, CD19+, and αß and γδ subsets were measured in the peripheral blood of all participants. RESULTS: The levels of CD3+, CD4+, CD8+, and CD19+ lymphocytes were decreased in CD patients compared with the control group (P = 0.002, 0.049, 0.003, and 0.023, respectively). Although both γδ and αß T lymphocytes were lower in patients with CD, γδ T subsets showed the lowest levels in CD patients (mean 0.0259 × 10(9)/l) versus healthy controls (mean 0.0769 × 10(9)/l), P < 0.001. In particular, γδ CD8+ T subsets (mean 0.0068 × 10(9)/l) had the largest difference compared to the control group (mean 0.0199 × 10(9)/l), P = 0.008. CONCLUSIONS: There is a decrease in the global lymphocyte population in the peripheral blood of patients with CD compared to healthy controls. This decrease is more evident in γδ T lymphocytes, especially γδ CD8+ T subsets. Our conclusion is that these results support the theory that a complex alteration of immune responses that affects the total numbers and function of γδ T cells is present in CD.