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.

Deficit of interleukin 7 in septic patients.

We recently demonstrated an overall decrease of all αß and specially γδ T cell subsets in patients with sepsis compared with healthy subjects. IL-7 is a crucial factor for development of γδ T cells and survival in sepsis but its association with sepsis severity, evolution of organ failure and death still has not been investigated. Sera from 78 patients who met criteria for sepsis were analyzed vs control group. Septic patients showed the lowest levels of IL-7. Patients with severe sepsis reached levels of IL-7 higher than those observed in the groups of uncomplicated sepsis and septic shock. The frequency of γδ T cells at admission was lower in septic patients vs control group. At the time of admission, the frequency of γδ T cells in septic patients who subsequently died was lower than the observed in the group of patients that instead survived.

Association of γδ T cells with disease severity and mortality in septic patients.

Gamma-delta T cells are the most abundant of all epithelial-resident lymphocytes and are considered a first line of defense against pathogens in the mucosa. Our objective was to confirm the reduction in γδ T cell subsets and its relationship with mortality in patients with sepsis. We studied 135 patients with sepsis attended in the emergency department and intensive care unit of two hospitals and compared them with a similar control group of healthy subjects. The αß and γδ T cell subsets were determined via flow cytometry according to the stage of the sepsis and its relationship with mortality. All the lymphocyte subsets were reduced with respect to the corresponding subsets in the control group. All the γδ T cell populations decreased significantly as the septic picture worsened. Furthermore, γδ T cells showed decreases at days 2, 3, and 4 from the start of sepsis. Twenty-six patients with sepsis died (19.3%). The γδ T cells, specifically, the CD3(+) CD56(+) γδ T cells, were significantly reduced in those septic patients who died. Our results indicate that, during sepsis, γδ T cells show the largest decrease and this reduction becomes more intense when the septic process becomes more severe. Mortality was associated with a significant decrease in γδ T cells.

Epidemiology of sepsis in the Valencian Community (Spain), 1995-2004.

OBJECTIVE: To study the incidence of sepsis in the Valencian Community (Spain) during a period of 10 years (1995-2004). METHODS: We downloaded data on discharge diagnoses of septicemia in all 26 public hospitals in the Valencian Community during the 10-year study period, as well as the additional discharge diagnoses of each patient. RESULTS: We identified 33,767 cases of sepsis during the study period. The age-standardized incidence rates among men increased from 64.11 (95% confidence interval [CI], 60.37-67.85) cases per 100,000 population in 1995 to 114.02 (95% CI, 109.02-118.50) cases per 100,000 population in 2004 (P < .001), and those among women increased from 45.08 (95% CI, 42.01-48.15) cases per 100,000 population in 1995 to 83.62 (95% CI, 79.85-87.39) cases per 100,000 population in 2004 (P < .001). Gram-negative bacteria were the most frequently involved microorganisms (in 21.4% of cases), and there was a significant increase in the number of sepsis cases caused by these organisms from 1999 onward. The mortality rate was approximately 42.5% among patients hospitalized for sepsis, and mortality was associated with organ failure. In addition, mortality was associated with the microorganism responsible not being known, with infection due to fungi, and with polymicrobial sepsis. CONCLUSIONS: The rates of hospitalization both for sepsis overall and for severe sepsis in the Valencian Community (Spain) are lower than those in other countries but are increasing, by 5% each year. The increase in the number of cases in which gram-negative bacteria are the cause of sepsis is notable.

Secretory immunoglobulin A (sIgA) deficiency in serum of patients with GALTectomy (appendectomy and tonsillectomy).

INTRODUCTION: In adult human beings, 80-85% of the immune cells are located in the digestive tract mucosa; hence the importance of the Gut Associated Lymphoid Tissue (GALT) in host defence. We studied the influence of the surgical removal of two important parts of the gut associated with lymphoid tissue (tonsillectomy and appendectomy) on immune parameters. METHODS: One hundred and sixty patients were enrolled in this study. They were divided into four groups of forty patients each and matched for gender and age: group 1, appendectomized and tonsillectomized; group 2, only appendectomized; group 3, only tonsillectomized; and group 4, control group, neither tonsillectomized nor appendectomized. We analysed in blood: hemogram, protein electrophoresis, lymphocytic populations (T4 cells, T8 cells, NK cells), IgG, IgM, IgA immunoglobulin, and their fractions IgA1, IgA2, and secretory IgA. RESULTS: Levels of secretory IgA in serum of patients in group 1 were significantly lower than in the other three groups (1.89 mg/dl, group 1; 2.32 mg/dl, group 2; 2.19 mg/dl, group 3 and 4.97 mg/dl, group 4; p<0.0001). Also, the values found in the two groups that had undergone only one of the operations were clearly lower than in control patients (p<0.0001). In this study, the reduction was sustained for a period of between 3 months and 3 years in appendectomized patients, and more than 20 years in tonsillectomized patients. IN SUMMARY: GALTectomy (appendectomy and tonsillectomy) significantly decreases secretory IgA levels in serum. The decrease is more intense when both operations have been done.