Altered expression of alpha 4 beta 7, a gut homing integrin, by circulating and mucosal T cells in colonic mucosal inflammation.

BACKGROUND AND AIMS: Expression of alpha 4 beta 7 on memory T lymphocytes identifies a cell population that preferentially migrates to the gut. Detection of alpha 4 beta 7 on circulating lymphocytes may permit the identification of specific subsets trafficking between the circulation and the gut in inflammatory bowel diseases. PATIENTS: Samples and clinical details were taken from patients with Crohn's disease (CD), ulcerative colitis (UC), diverticulitis/ infectious colitis, and healthy controls. METHODS: Peripheral blood and lamina propria mononuclear cells were isolated. Cells were labelled with CD3, CD4, CD25, CD45RO or alpha 4 beta 7. RESULTS: Median levels of circulating total memory T cells (CD4+CD45RO+) were increased in CD (p < 0.01) and UC (p < 0.05). However, the proportion of systemic gut homing T cells (CD4+CD45RO+ alpha 4 beta 7+) was decreased in CD (p < 0.05), UC (p < 0.002), and inflammatory controls (p < 0.05). Levels of activated gut homing T cells (CD4+CD25+ alpha 4 beta 7+) were increased in CD (p < 0.01) and UC (p < 0.05). For both CD4+CD45RO+ and CD4+CD25+ cells, the proportion of lymphocytes coexpressing alpha 4 beta 7 was decreased compared with controls. In small and large intestine lamina propria, expression of alpha 4 beta 7+ on CD3+ cells was extensive, although it was decreased in CD (p < 0.03), UC (p < 0.05), and inflammatory controls (p < 0.05). CONCLUSIONS: Circulating and mucosal gut homing lymphocyte populations are changed in patients with colonic inflammation. This may arise due to a dilution effect from recruited naive T cells, or from integrin down regulation. Changes in general CD4+ lymphocyte populations mask more subtle variations in those cells with gut homing potential.     

HIV感染者/AIDS患者外周血CD38 HLA-DR分子在CD4+ CD8+T淋巴细胞上的表达

目的　观察国内艾滋病病毒 (HIV)感染者 /艾滋病 (AIDS)患者外周血CD38、HLA DR分子在CD+4 、CD+8T淋巴细胞上表达的变化 ,并探讨这些变化的临床意义。方法　用流式细胞仪检测 5 1例正常对照、14例HIV感染者和 3 6例AIDS患者的外周血CD+4 、CD+8T淋巴细胞表面的CD38、HLA DR分子的表达 ,用分枝DNA(bDNA)法检测 11例HIV感染者和 18例AIDS患者的血浆病毒载量。结果　CD+4 HLA DR+细胞百分比显示 ,AIDS组显著高于正常组及HIV组 ;CD+8HLA DR+T细胞百分比显示HIV组与AIDS组间无差异 ,而它们均显著高于正常组。CD+8、CD38+细胞百分比则是AIDS组 >HIV组 >正常组 ,CD+8CD38+、CD+8HLA DR+、CD+4 HLA DR+细胞百分比与病毒载量显著正相关。结论　在HIV感染过程中 ,HLA -DR+、CD38+在CD+4 、CD+8T淋巴细胞上的表达均显著增加 ,反映T淋巴细胞异常激活 ;尤其是CD+8CD38+细胞百分比随着疾病进展逐渐升高 ,预示疾病进展程度。在评价HIV感染者和AIDS患者的免疫状况时 ,不仅要考虑免疫细胞数量和功能的变化 ,还应考虑免疫细胞的激活水平     

Lack of Evidence for Small Intestinal Mucosal T-Cell Activation as a Pathogenic Mechanism in African HIV-Associated Enteropathy

The role of mucosal T-cell activation in HIV-associated enteropathy is uncertain. Twenty Zambian patients with AIDS and chronic diarrhea were studied, as were nine controls. Distal duodenal biopsies were taken at endoscopy. Morphometric analysis and dual color immunofluorescence staining were performed. Villous height was reduced [177 (118–228) vs 305 (244–358) m P = 0.002] and crypt depth increased [220 (164–202) vs 194 (164–202) m P = 0.008] in AIDS patients compared to controls. CD3⁺CD4⁺ T cells were reduced in AIDS patients compared to controls [12.9 (5.7–25.2) vs 47.6 (33.4–65.5)% P = 0.04]. There was no significant difference in expression of CD8, CD25, CD69, HML-1, or HLA-DR on T cells between the AIDS patients and controls, with the exception of CD3⁺HML-1⁺ cells, which were increased in AIDS patients (P = 0.05). Small intestinal T-cell activation was similar between AIDS patients and controls. We conclude, therefore, that this mechanism is not likely to be important in the pathogenesis of HIV-associated enteropathy.     

HIV infection-associated immune activation occurs by two distinct pathways that differentially affect CD4 and CD8 T cells

HIV infection is characterized by a brisk immune activation that plays an important role in the CD4 depletion and immune dysfunction of patients with AIDS. The mechanism underlying this activation is poorly understood. In the current study, we tested the hypothesis that this activation is the net product of two distinct pathways: the inflammatory response to HIV infection and the homeostatic response to CD4 T cell depletion. Using ex vivo BrdU incorporation of PBMCs from 284 patients with different stages of HIV infection, we found that CD4 proliferation was better predicted by the combination of CD4 depletion and HIV viral load (R² = 0.375, P < 0.001) than by either parameter alone (CD4 T cell counts, R² = 0.202, P < 0.001; HIV viremia, R² = 0.302, P < 0.001). Interestingly, CD8 T cell proliferation could be predicted by HIV RNA levels alone (R² = 0.334, P < 0.001) and this predictive value increased only slightly (R² = 0.346, P < 0.001) when CD4 T cell depletion was taken into account. Consistent with the hypothesis that CD4 T cell proliferation is driven by IL-7 as a homeostatic response to CD4 T cell depletion, levels of phosphorylated STAT-5 were found to be elevated in naive subsets of CD4 and CD8 T cells from patients with HIV infection and in the central memory subset of CD4 T cells. Taken together these data demonstrate that at least two different pathways lead to immune activation of T cells in patients with HIV infection and these pathways differentially influence CD4 and CD8 T cell subsets.     

Activation-induced CD4+ T cell death in HIV-positive individuals correlates with Fas susceptibility, CD4+ T cell count, and HIV plasma viral copy number

The relevance of activation-induced cell death (AICD) of CD4+ T cells to AIDS pathogenesis is unknown. The present study investigates the relationship of AICD to a defined molecular mechanism regulating peripheral T cell homeostasis, Fas-mediated apoptosis, and clinical correlates of the pathogenesis of AIDS. Increased pokeweed mitogen (PWM)-induced AICD (22.8 versus 4.4%, p = 0.006) and Fas-mediated apoptosis (27.7 versus 12.0%, p = 0.002) of CD4+ T cells were observed in HIV+ versus HIV- individuals. Similarly, increased PWM-mediated AICD (16.2 versus 2.2%, p < 0.001) and Fas-mediated apoptosis (25.8 versus 7.6%, p = 0.005) were noted in CD8+ T cells from HIV+ versus HIV- individuals. PWM-induced AICD of CD4+ T cells was blocked (83% median specific inhibition) by Fas-blocking antibodies, whereas PWM-induced AICD of CD8+ T cells was Fas independent. Comparison between PWM- and anti-CD3-mediated AICD of CD4+ T cells indicated that PWM- and not CD3-induced AICD is Fas dependent. HIV+ individuals with an HIV RNA copy number of <30,000 copies/ml had lower PWM-induced AICD of CD4+ T cells than did those with an HIV RNA copy number of >30,000 copies/ml (5.7 versus 22.1%, p = 0.034), and PWM-induced AICD inversely correlated with CD4+ T cell count (R = -0.567, p = 0.043). Initiation of HAART decreased PWM-induced CD4+ T cell AICD from 24.4 to 9.4% posttreatment (p = 0.035). These results demonstrate that PWM-induced AICD of CD4+ T cells from HIV+ individuals is mediated by Fas/FasL, parallels the in vivo susceptibility of the CD4+ T cell to Fas-mediated apoptosis, and correlates with clinical markers of AIDS pathogenesis and response to HAART.     

Angiogenesis in gastric ulcers: impaired in patients taking non-steroidal anti-inflammatory drugs.

Non-steroidal anti-inflammatory drug (NSAID) therapy is associated with delayed gastroduodenal ulcer healing. In rats the degree of angiogenesis (new vessel formation) within the ulcer bed correlates strongly with the extent and speed of ulcer healing and may be inhibited by NSAIDs. This study therefore assessed the vascularity of 38 antral gastric ulcers immunohistochemically, using CD31 a vascular endothelial cell marker, in 17 patients taking NSAIDs and 19 control patients. In the superficial granulation tissue NSAID therapy was associated with a significant reduction in the median number of capillaries (13.5 (IQR: 9.5-18) v 23.5 (14-31) (p < 0.005)), number of vessel buds (6 (4-12.5) v 17 (12-23) (p < 0.05)), and maximum vessel diameter (29 (20.75-30.75) v 33.75 (24-45) (p < 0.05)) when compared with controls. In deep granulation tissue NSAID therapy was similarly associated with a significant reduction in the number of capillaries (9 (6.5-12) v 14 (9-19.25) (p < 0.04)), number of vessel buds (5 (3.5-8.5) v 13 (7-16.5) (p < 0.01)), and maximum vessel diameter (23 (18-20.5) v 33 (21.5-45) (p < 0.02)). There were no differences in vascularity in the adjacent glandular mucosa. Impairment of angiogenesis may be an important mechanism of NSAID related delayed ulcer healing.     

Natural killer cells and gamma delta T cells in scleroderma: relationship to disease duration and anti-Scl-70 antibodies.

OBJECTIVES--To examine the expression of the natural killer (NK) antigen CD56, and T cell receptor delta chain antigen (TCR delta), expressed on the gamma delta T cell subset, in patients with scleroderma, and to correlate levels of expression with clinical characteristics. METHODS--Peripheral blood mononuclear cells (PBMCs) from 15 patients with scleroderma and 11 controls were obtained from heparinised blood on a ficoll/hypaque gradient, stained with monoclonal antibodies, and examined by flow cytometry for expression of CD56 and TCR delta. RESULTS--Overall, the proportion of PBMCs expressing CD56 in the patient group (14.4 (SEM 2.6)%) was not significantly different from controls (8.75 (2.6)%). The greatest levels of expression were found in patients late (more than three years) in their disease course (18.1 (3.3)%) and in patients who did not express anti-Scl-70 antibodies (17.1 (3.5)%). The proportion of gamma delta T cells was significantly lower in the patient group (1.61 (0.52)% v control 2.61 (0.46)%) (p < 0.05). Patients early in their disease or with anti-Scl-70 antibodies accounted for the reduction in gamma delta T cells (0.71 (0.29)% and 0.96 (0.41)% (p < 0.01 and p < 0.05, respectively). CONCLUSIONS--This study emphasis that NK and gamma delta T cell numbers vary depending upon patient characteristics and may help explain prior contradictory reports. Decreased numbers of gamma delta T cells were seen in scleroderma patients, especially those with anti-Scl-70 antibodies and a disease duration of less than three years.     

Mononuclear phagocytes of blood and bone marrow: comparative roles as viral reservoirs in human immunodeficiency virus type 1 infections.

We examined human immunodeficiency virus (HIV) production in cultured mononuclear cells from 36 seropositive homosexual males. Production was detected by using an HIV p24 antigen ELISA assay in blood mononuclear cells in 54% of asymptomatic, 71% of acquired immunodeficiency syndrome (AIDS)-related complex, and 100% of AIDS patients. When the peripheral blood mononuclear cells were separated into monocytes and CD4+ T cells, we found that the CD4+ T-cell fraction was preferentially infected in the three clinical stages. The ability to isolate HIV from blood monocyte-derived macrophages was similar in the three stages (24-33%) and required coculture with phytohemagglutinin-stimulated lymphoblasts. Bone marrow and blood mononuclear cells cultured simultaneously yielded virus from both sources in 13 individuals. Again the prime source of virus was the nonadherent bone marrow mononuclear cells, which contained CD4+ T cells, and not the adherent monocyte-enriched fraction. We conclude that blood mononuclear cells yield productive virus more readily as disease progresses and that infection is detected in association with CD4+ T-cell-enriched fractions. In our large sample of patients, monocyte infection was detected in only a small fraction, suggesting that this cell type is neither a primary nor an exclusive reservoir of HIV infection.     

HIV isolation and clinical markers on the seropositive subjects

We investigated 18 anti-HIV seropositive subjects with respect to the isolation of HIV from peripheral blood mononuclear cells (PBMC) and cellular and serologic markers for progression to AIDS. The subjects included homosexuals and recipients of blood products. Three had AIDS, an asymptomatic subject developed AIDS during the study and 14 of the remaining have remained asymptomatic. HIV was isolated from all AIDS patients and 7 asymptomatic subjects. Moreover HIV was detected significantly sooner in symptomatic patients than in asymptomatic subjects. The reductions in CD4 lymphocytes number and CD4/CD8 ratio, as well as anti-HIV core (p24, p17) antigens negativity correlated with deterioration of clinical symptoms and successful HIV isolation. The isolates from AIDS patients and from an asymptomatic subject who 9 months later developed AIDS were infective and cytotoxic to MT-4 cells, however isolates from asymptomatic subjects were not infective. These findings indicate that disease progression correlates with the appearance of variant viruses that are more infective and cytopathic.     

Histoplasmosis in Patients With Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS): Multicenter Study of Outcomes and Factors Associated With Relapse

Although discontinuation of suppressive antifungal therapy for acquired immunodeficiency syndrome (AIDS)-associated histoplasmosis is accepted for patients with immunologic recovery, there have been no published studies of this approach in clinical practice, and minimal characterization of individuals who relapse with this disease. We performed a multicenter retrospective cohort study to determine the outcome in AIDS patients following discontinuation of suppressive antifungal therapy for histoplasmosis.Ninety-seven patients were divided into a physician-discontinued suppressive therapy group (PD) (38 patients) and a physician-continued suppressive therapy group (PC) (59 patients). The 2 groups were not statistically different at baseline, but at discontinuation of therapy and at the most recent follow-up there were significant differences in adherence to therapy, human immunodeficiency virus (HIV) RNA, and urinary Histoplasma antigen concentration. There was no relapse or death attributed to histoplasmosis in the PD group compared with 36% relapse (p < 0.0001) and 5% death (p = 0.28) in the PC group. Relapse occurred in 53% of the nonadherent patients but not in the adherent patients (p < 0.0001). Sixty-seven percent of patients with initial central nervous system (CNS) histoplasmosis relapsed compared to 15% of patients without CNS involvement (p = 0.0004), which may be accounted for by nonadherence. In addition, patients with antigenuria above 2.0 ng/mL at 1-year follow-up were 12.82 times (95% confidence interval, 2.91–55.56) more likely to relapse compared to those with antigenuria below 2.0 ng/mL.Discontinuation of antifungal therapy was safe in adherent patients who completed at least 1 year of antifungal treatment, and had CD4 counts >150 cells/mL, HIV RNA <400 c/mL, Histoplasma antigenuria <2 ng/mL (equivalent to <4.0 units in second-generation method), and no CNS histoplasmosis.     

Natural history of AIDS related sclerosing cholangitis: a study of 20 cases.

A case control study of AIDS related sclerosing cholangitis indicates that it has no overall influence on prognosis, but is responsible for a striking reversal of the usual inverse correlation of age and survival in HIV infection. Pain, the principal symptom, was controlled in surviving patients with analgesics alone. Twenty consecutive patients with AIDS related sclerosing cholangitis, defined from at least two characteristic lesions at endoscopic retrograde cholangiopancreatography, were followed for a minimum of 10 months or until death. Median age was 33.5 years (range 27-50). All had abdominal pain; 11 had diarrhoea. Alkaline phosphatase was > 2X normal in 13, but the bilirubin was raised in only three. The median CD4 was 0.024 x 10(9)/l (0.005-0.341). Thirteen had cryptosporidiosis, six had active cytomegalovirus, five had no gastrointestinal pathogen. Three patients are alive without AIDS related sclerosing cholangitis symptoms at 10, 11, and 21 months. Seventeen have died at median 7 (1-23) months. Cytomegalovirus therapy had no apparent influence. The initial CD4 was < 0.11 in all those dying within six months, but correlation of CD4 with prognosis was otherwise poor. Controls, matched for age, CD4, and opportunistic infections had virtually identical overall outcome (median survival 7.5 months) and the expected worse prognosis with increasing age. Increasing age, however, appeared protective in AIDS related sclerosing cholangitis (r = +0.6; p < 0.05): this is not explained by disproportionate degrees of immunosuppression, nor by opportunistic infections.     

Oesophageal motor response to reflux is not impaired in reflux oesophagitis.

Whether the oesophageal motor response to reflux, as recorded over 24 hours, is impaired in patients with reflux oesophagitis was investigated. Twenty three patients with oesophagitis (Savary-Miller grades I-IV) and 23 control subjects matched for age and sex underwent 24 hour ambulatory pH and pressure monitoring. All contractions occurring in the 2 minute period after the onset of each reflux episode were analysed automatically using dedicated computer algorithms. A total of 2085 reflux episodes occurred--1513 in patients and 572 in controls. Oesophageal acid exposure was greater (p < 0.01) in patients than in controls (mean (SEM) % time pH < 4 13.3 (1.7) and 5.3 (0.9)%, respectively). The mean duration of the supine reflux episodes was longer (p < 0.01) in patients (11.2 (2.8) minutes) than in controls (5.1 (1.8) minutes). In the upright period, no significant differences in the motor response to reflux were found. In the supine period, the patients showed a higher number of reflux induced contractions (4.40 (0.61) v 1.62 (0.31), p < 0.01), a higher contraction amplitude (4.55 (0.42) v 2.99 (0.71) kPa, p < 0.02) and longer contractions (1.86 (0.19) v 1.32 (0.29) seconds, p < 0.05). The percentages of peristaltic and simultaneous contractions that occurred in response to supine reflux did not differ between the two groups. In patients with reflux oesophagitis the motor response of the oesophagus to reflux is not impaired. During the supine period the response is even stronger than in healthy controls.     

Risk factors for liver fibrosis among human immunodeficiency virus monoinfected patients using the FIB4 index in Morocco

AIM: To study the prevalence and risk factors of significant hepatic fibrosis in Moroccan human immunodeficiency virus (HIV) monoinfected patients.METHODS: We conducted a cross-sectional study among HIV monoinfected patients (negative for hepatitis B surface antigen and hepatitis C antibody). Clinical and laboratory data were collected from the data base of the Infectious Diseases Unit in Ibn Rochd Hospital Center [age, gender, duration of HIV infection, CD4 T lymphocyte count, HIV viral load, glycemia and current or prior use of antiretroviral and antiretroviral therapy (ART) duration]. The primary outcome was a FIB4 score > 1.45. Multivariable logistic regression identified independent risk factors for FIB4 > 1.45.RESULTS: A FIB4 score > 1.45 was identified in 96 among 619 (15.5%). HIV monoinfected patients followed up between September 1990 and September 2012. Multivariate analysis showed that only a viral load > 75 (OR = 2.23, 95%CI: 1.36-3.67), CD4 > 200 cells/mm³ (OR = 0.39, 95%CI: 0.21-0.72) and age at FIB4 index calculation (OR = 1.10, 95%CI: 1.07-1.13) were independently associated with the occurrence of FIB4 index (> 1.45). Gender, duration of HIV infection, glycemia, use of antiretroviral therapy and ART duration were not associated with significant fibrosis by FIB4.CONCLUSION: FIB4 score > 1.45 was found in 15.5% of Moroccan HIV monoinfected patients. Age, HIV viremia > 75 copies/mL and CD4 count > 200 cells/mm³ are associated with liver fibrosis. Further studies are needed to explore mechanisms for fibrosis in HIV monoinfected patients.     

Advanced glycation end products induce glomerular sclerosis and albuminuria in normal rats.

High levels of tissue advanced glycation end products (AGEs) that result from the spontaneous modification of proteins by glucose occur in diabetes and aging. To address the potential pathogenic role of AGEs in the glomerulosclerosis of diabetes or nephrosclerosis of aging, doses of AGE-modified rat albumin (25 mg per kg per day, i.v.) sufficient to elevate circulating AGE levels to the range of diabetic serum were administered daily to healthy rats alone or in combination with the AGE inhibitor aminoguanidine. After 5 months, the AGE content of renal tissues in AGE-treated rats rose to 50% above controls (P < 0.025), whereas serum contained 2.8-fold greater AGE levels (P < 0.025). Light and electron microscopy of kidneys from AGE-treated rats revealed a more than 50% increase in glomerular volume compared to controls (P < 0.001), significant periodic acid/Schiff reagent-positive deposits, basement membrane widening, and mesangial extracellular matrix increase and indicated significant glomerulosclerosis compared to untreated (P < 0.002) or albumin-treated controls (P < 0.002). These changes were associated with significant loss of protein (P < 0.005) and albumin (P < 0.002) in the urine of AGE-treated rats compared to controls. Cotreatment with aminoguanidine markedly limited both the structural and functional defects. These in vivo data demonstrate that AGEs influence glomerular structure and function in a manner leading to glomerulosclerosis. The effects are AGE-specific, as they are ameliorated by a pharmacological AGE inhibitor, aminoguanidine.     

Helicobacter pylori related hypergastrinaemia is the result of a selective increase in gastrin 17.

Helicobacter pylori infection increases the serum concentration of gastrin, and this may be one of the mechanisms by which it predisposes to duodenal ulceration. Different forms of circulating gastrin were studied both basally and postprandially in 13 duodenal ulcer patients before and one month after eradication of H pylori. Three antisera that are specific for particular regions of the gastrin molecules were used. Gel chromatography indicated that > 90% of the circulating gastrin consisted of gastrin (G) 17 and G34 both before and after eradicating the infection. The basal median total immunoreactive gastrin concentration fell from 26 pmol/l (range 11-43) to 19 pmol/l (8-39) (p < 0.05), entirely because of a fall in G17 from 6 pmol/l (< 2.4-25) to < 2.4 pmol/l (< 2.4-23) (p < 0.001). The median (range) basal G34 values were similar before (15 pmol (2-36)) and after (10 pmol (2-30)) eradication. The median total immunoreactive gastrin concentration determined 20 minutes postprandially fell from 59 pmol/l (38-114) to 33 pmol/l (19-88) (p < 0.005), and again this was entirely the result of a fall in G17 from 43 pmol/l (9-95) to 17 pmol/l (< 2.4-52) (p < 0.001). The median postprandial G34 values were similar before (13 pmol/l, range 6-42) and after (15 pmol/l, range 6-30) eradication. Eating stimulated a noticeable rise in G17 but little change in G34, both in the presence and absence of H pylori. The finding that H pylori infection selectively increases G17 explains why the infection causes mainly postprandial hypergastrinaemia. G17 is increased selectively because H pylori predominantly affects the antral mucosa which is the main source of G17 whereas G34 is mainly duodenal in origin. This study also indicates that the increased concentration of gastrin in H pylori infection is the result of an increase in one of the main biologically active forms of the hormone.     

CXCR5~+CD8~+ T细胞在HIV感染中的免疫特征及其与疾病进展关系的研究

目的探讨HIV感染者外周血CXCR5~+CD8~+T细胞的频率、功能变化及其与病情进展的相关性。方法收集40例HIV感染者和15例健康对照者,采用流式细胞分析术检测其外周血CXCR5~+CD8~+T细胞频率及IFN-γ和IL-10表达,并分析其与血浆HIV载量和外周血CD4~+T细胞计数的相关性。结果与健康对照组相比,HIV感染组外周血CXCR5~+CD8~+T细胞频率上调(P0.05),且与外周血CD4~+T细胞计数呈弱正相关(r=0.349,P=0.027),与血浆HIV载量呈弱负相关(r=-0.377,P=0.040);HIV感染者外周血CXCR5~+CD8~+T细胞IFN-γ表达与血浆HIV载量呈负相关(r=-0.514,P=0.002);而CXCR5~+CD8~+T细胞IL-10的表达在HIV感染者中明显上调(P0.05),与外周血CD4~+T细胞计数呈弱负相关(r=-0.317,P=0.046),与血浆HIV载量呈正相关(r=0.670,P=0.002)。结论 HIV感染者外周血CXCR5~+CD8~+T细胞频率功能变化与疾病进展密切相关。     

Perturbation of the T cell repertoire in rheumatoid arthritis

Aberrations in the T cell repertoire with the emergence of oligoclonal populations have been described in patients with rheumatoid arthritis (RA). However, the extent of the repertoire perturbations as well as the underlying mechanisms are not known. We now have examined the diversity of the peripheral CD4 T cell repertoire by determining the frequencies of arbitrarily selected T cell receptor (TCR) β-chain sequences. Healthy individuals displayed a highly diverse repertoire, with a median frequency of individual TCR β-chain sequences of 1 in 2.4 × 10⁷ CD4 T cells. In RA patients, the median TCR β-chain frequency was increased 10-fold, indicating marked contraction of the repertoire (P < 0.001). The loss in TCR diversity was not limited to CD4 memory T cells but also involved the compartment of naive T cells, suggesting that it reflected an abnormality in T cell repertoire formation and not a consequence of antigen recognition in the synovium. Also, control patients with chronic inflammatory disease such as hepatitis C expressed a diverse repertoire indistinguishable from that of normals. Telomere length studies indicated an increased replicative history of peripheral CD4 T cells in RA patients, suggesting an enhanced turnover within the CD4 compartment. Compared with age-matched controls, terminal restriction fragment sizes were 1.7 kilobases shorter (P < 0.001). These data demonstrate an altered CD4 T cell homeostasis in RA that may contribute to the autoimmune response as well as to the immunodeficiency in these patients.     

Immunohistochemical markers for arthritis in psoriasis.

OBJECTIVES--To examine the immunohistological features in the involved skin of patients with psoriatic arthritis (PA) (n = 15), compared with those in involved skin from patients with psoriasis but no arthritis (n = 5), and with a group with normal skin (n = 4), to identify markers for arthritis in psoriasis. METHODS--Skin was obtained from patients by 6 mm punch biopsy and normal skin was provided by the department of plastic surgery. Samples were stained with monoclonal antibodies against T cells (CD3, CD8, CD4, CD45Ro), B cells (CD20), macrophages (mac387), vascular endothelium (FVIII-related antigen) and a Langerhan's cell marker (p155). The number of cells/vessels staining with each monoclonal antibody was calculated and serial sections of skin were examined to estimate the presence of DR+ keratinocytes. RESULTS--There were significantly more CD45Ro T-cells and blood vessels in patients with psoriatic arthritis compared with both psoriasis alone, and with normal controls (p < 0.02). While B-cells were not seen in psoriasis without arthritis or in normal skin, a small but significant number were observed in PA (p < 0.02). Furthermore, while DR+ keratinocytes were present in both psoriatic arthritis and psoriasis skin, there were significantly more DR+ cells in the psoriatic arthritis epidermis compared with psoriasis alone (p < 0.02). CONCLUSIONS--This study suggests that increased numbers of CD45Ro T-cells, greater vascularity, the presence of B-cells, and increased numbers of DR+ epidermal cells are markers for arthritis in patients with psoriasis.     

Increased small intestinal apoptosis in coeliac disease.

BACKGROUND: Coeliac disease (CD) mucosa is flattened despite epithelial hyperproliferation. AIMS: To establish mechanisms of cell loss in CD. PATIENTS: 14 controls, 17 active CD patients, and 16 maintained with gluten free diet. METHODS: Programmed cell death was examined in small intestinal biopsy specimens by staining fragmented DNA using terminal uridine deoxynucleotidyl nick end labelling (TUNEL), in comparison with haematoxylin and eosin stained adjacent sections. Double staining with anti-CD45 antibodies determined the origin of apoptotic cells. Apoptosis was graded from 1-3 (< 5, 5-20, > 20% respectively). Proliferating cells, immunostained by Ki-67 (MIB-1) antibody, were counted. RESULTS: Apoptotic cells were seen rarely by haematoxylin and eosin but more readily by TUNEL. In controls, 1.4 +/- 0.2% of epithelial cells were apoptotic (mean grade 1.1), mainly located in the upper villus. In active CD, frequent apoptotic cells were distributed throughout the crypt-villus unit (mean grade 2.4), decreasing after treatment to 1.1 (p < 0.001) even when still histologically abnormal. CD45 antibodies rarely stained apoptotic cells in active CD. The number of TUNEL positive cells correlated with proliferating cell number (p < 0.001). CONCLUSION: Enterocyte apoptosis is greatly increased in untreated CD, correlates with proliferation, and falls to normal with a gluten free diet, before histological improvement. Increased apoptosis may be responsible for villous atrophy in CD.