Protective effect of IgM against colonization of the respiratory tract by nontypeable Haemophilus influenzae in patients with hypogammaglobulinemia.

BACKGROUND: Primary immunoglobulin deficiencies lead to recurrent bacterial infections of the respiratory tract and bronchiectasis, even with adequate immunoglobulin replacement therapy. It is not known whether patients able to secrete IgM (eg, those with hyper-IgM [HIgM] syndrome) are as susceptible to these infections as patients who lack IgM production (eg, those with panhypogammaglobulinemia [PHG]). OBJECTIVE: This study is aimed at identifying specific microbiological and clinical (infections) characteristics that distinguish immunoglobulin-substituted patients with PHG from patients with HIgM syndrome. METHODS: A cohort of patients with HIgM syndrome (n = 25) and a cohort of patients with PHG (n = 86) were monitored prospectively for 2 years while receiving similar polyvalent immunoglobulin replacement therapies. Regular bacterial analyses of nasal swabs and sputum were performed, and clinical events were recorded. In parallel, serum and saliva IgM antibody concentrations were measured. RESULTS: When compared with patients with PHG, patients with HIgM syndrome were found to have a significantly lower risk of nontypeable Haemophilus influenzae carriage in particular (relative risk, 0.39; 95% CI, 0.21-0.63). Moreover, patients with HIgM syndrome (including those unable to generate somatic hypermutations of immunoglobulin genes) displayed anti-nontypeable H influenzae IgM antibodies in their serum and saliva. Also, patients with HIgM syndrome had a lower incidence of acute respiratory tract infections. CONCLUSIONS: IgM antibodies appear to be microbiologically and clinically protective and might thus attenuate the infectious consequences of a lack of production of other immunoglobulin isotypes in patients with HIgM syndrome. Polyvalent IgG replacement therapy might not fully compensate for IgM deficiency. It might thus be worth adapting long-term antimicrobial prophylactic regimens according to the underlying B-cell immunodeficiency phenotype.

Mortality and demographic recovery in early post-black death epidemics: Role of recent emigrants in medieval Dijon.

OBJECTIVE AND METHODS: We analyze the influence of population movement on susceptibility to death and resilience during two epidemics occurring in Dijon soon after the Black Death. Using a specific program designed to propose links between entries in annual tax registers, we define tentative heads of household, the elapsed time since their first registration and their ties with other persons within the city. RESULTS: During the 1400 epidemic heads of household who were registered for 1-3 years die in large numbers, whereas during years without epidemics, their death rate is lower than that of heads of household who were registered longer. Recent registration is an epidemic vulnerability factor only in association with a low taxation status, which, when isolated, does not influence mortality. A lack of familial ties within Dijon is another vulnerability factor among the recently registered. This suggests that poor, recent emigrants are more affected by epidemic mortality. In contrast, the mortality of recently registered heads of household is indistinct during a later epidemic occurring after several years of major famine that may have selected the more resistant emigrants and/or excluded the more miserable of them from our analysis. In contrast to the first one, this second epidemic is followed by rapid demographic recovery. This latter recovery is fully explained by the contribution of poor, newly registered heads of household without ties in Dijon. CONCLUSION: Our results outline the interaction between population movement and low socioeconomic status on death susceptibility in historical plagues and show that poor recent emigrants may also be key players in the resilience of the population after an epidemic.

Balance between pro and anti-inflammatory cytokines in patients with acute alcoholic hepatitis.

UNLABELLED: The ability of endogenous IL-10 to modulate inflammatory response and to limit hepatotoxicity has been shown in several models of liver injury. AIMS: The objectives of this study were to evaluate the relationship between liver disease and the balance between pro and anti-inflammatory cytokines in acute alcoholic hepatitis. METHODS: Twenty-five patients with pure steatosis, 17 with cirrhosis and mild acute alcoholic hepatitis (discriminant function value<32) and 41 patients with cirrhosis and severe acute alcoholic hepatitis (discriminant function value >=32) were studied. Plasma levels of interleukin 10 (IL-10) and soluble TNF receptors (TNFsRp75 and 55) were analyzed using ELISA assays. Hepatocyte proliferative activity was assessed with proliferating cell nuclear antigen labeling index (PCNA-LI) on formalin-fixed paraffin embedded liver biopsy specimens. RESULTS: In patients with steatosis, cirrhosis with mild and severe acute alcoholic hepatitis, the plasma levels of IL-10 were higher (P<0.05) than in healthy controls. Between day 1 and day 8, the TNFsRp55/IL-10 ratio increased by 137 +/- 47 in the 10 patients with severe acute alcoholic hepatitis treated with prednisolone who died within 2 months and by 9.3 +/- 14 in the 19 patients still alive at 2 months (P=0.031). In patients with severe acute alcoholic hepatitis, PCNA-LI on liver biopsy was negatively correlated with the TNFsRp55/IL-10 ratio increase from day 1 to day 8 (r=- 0.42, P=0.11). PCNA-LI was positively correlated with TNFsRp75/TNFsRp 55 ratio increase from day 1 to day 15 (r=0.52; p<0.05). CONCLUSION: Our data suggest the anti-inflammatory system is up-regulated in patients with alcoholic liver disease. Nevertheless, in patients with severe acute alcoholic hepatitis, IL-10 production seems insufficient to modulate TNF-alpha cytotoxicity mediated by TNFRp55.

Historical Epidemics Cartography Generated by Spatial Analysis: Mapping the Heterogeneity of Three Medieval "Plagues" in Dijon.

OBJECTIVES: This work was designed to adapt Geographical Information System-based spatial analysis to the study of historical epidemics. We mapped "plague" deaths during three epidemics of the early 15th century, analyzed spatial distributions by applying the Kulldorff's method, and determined their relationships with the distribution of socio-professional categories in the city of Dijon. MATERIALS AND METHODS: Our study was based on a database including 50 annual tax registers (established from 1376 to 1447) indicating deaths and survivors among the heads of households, their home location, tax level and profession. The households of the deceased and survivors during 6 years with excess mortality were individually located on a georeferenced medieval map, established by taking advantage of the preserved geography of the historical center of Dijon. We searched for clusters of heads of households characterized by shared tax levels (high-tax payers, the upper decile; low-tax payers, the half charged at the minimum level) or professional activities and for clusters of differential mortality. RESULTS: High-tax payers were preferentially in the northern intramural part, as well as most wealthy or specialized professionals, whereas low-tax payers were preferentially in the southern part. During two epidemics, in 1400-1401 and 1428, areas of higher mortality were found in the northern part whereas areas of lower mortality were in the southern one. A high concentration of housing and the proximity to food stocks were common features of the most affected areas, creating suitable conditions for rats to pullulate. A third epidemic, lasting from 1438 to 1440 had a different and evolving geography: cases were initially concentrated around the southern gate, at the confluence of three rivers, they were then diffuse, and ended with residual foci of deaths in the northern suburb. CONCLUSION: Using a selected historical source, we designed an approach allowing spatial analysis of urban medieval epidemics. Our results fit with the view that the 1400-1401 epidemic was a Black Death recurrence. They suggest that this was also the case in 1428, whereas in 1438-1440 a different, possibly waterborne, disease was involved.

Continuous versus intermittent treatment strategies during primary HIV-1 infection: the randomized ANRS INTERPRIM Trial.

OBJECTIVES: The ANRS-112 INTERPRIM trial assessed whether fixed-cycles of antiretroviral treatment interruption (ART-STI) combined or not with pegylated interferon alpha-2b (peg-IFN) could lower viral load and achieve a healthier immune system in patients diagnosed during primary HIV-1-infection (PHI). DESIGN AND METHODS: Patients were randomized to receive either continuous ART (cART) during 72 weeks, or cART during 36 weeks followed by three ART-STIs, or the same ART-STIs associated with peg-IFN during the first 14 weeks and each interruption (ART-STI-IFN). Treatment was stopped at week 72. Final evaluation was based on plasma HIV-RNA level 6 months after the last treatment interruption. RESULTS: Eighty-seven percent of patients achieved undetectable HIV-RNA at week 32, with no deleterious impact of sequential treatment interruptions (STIs). Viral rebounds during interruptions were lower in the ART-STI-IFN than in the ART-STI group and during the second and third interruptions compared with the first one. However, HIV-RNA levels, CD4 T-cell counts and CD4 T/CD8 T ratios were similar between groups after the 6-month interruption, with a persistent effect on CD4 T cells and total cell-associated HIV-DNA levels. Predictive factors of virological outcome were HIV-RNA and HIV-DNA levels at PHI and HIV-DNA levels at treatment interruption. HIV-specific responses did not differ between strategies and were not associated with outcome. Forty-eight percent of patients experienced treatment resumption during long-term follow-up without difference between groups. CONCLUSION: When initiated during PHI, STIs associated or not with IFN did not result in a different outcome as compared to cART. All regimens showed a high response rate and a sustained immunological benefit after cessation.

Natural phosphorylation of CD5 in chronic lymphocytic leukemia B cells and analysis of CD5-regulated genes in a B cell line suggest a role for CD5 in malignant phenotype.

Chronic lymphocytic leukemia (CLL) results in the accumulation of B cells, presumably reflecting the selection of malignant cell precursors with Ag combined with complex alterations in protein activity. Repeated BCR stimulation of normal B cells leads to anergy and CD5 expression, both of which are features of CLL. Because CD5 is phosphorylated on tyrosine following BCR engagement and negatively regulates BCR signaling in normal B cells, we investigated its phosphorylation status and found it to be naturally phosphorylated on tyrosine but not on serine residues in CLL samples. To analyze the role of CD5, we established a B cell line in which CD5 is phosphorylated. Gene profiling of vector vs CD5-transfected B cells pointed out gene groups whose expression was enhanced: Apoptosis inhibitors (BCL2), NF-kappaB (RELB, BCL3), Wnt, TGFbeta, VEGF, MAPKs, Stats, cytokines, chemokines (IL-10, IL-10R, IL-2R, CCL-3, CCL-4, and CCR7), TLR-9, and the surface Ags CD52, CD54, CD70, and CD72. Most of these gene groups are strongly expressed in CLL B cells as compared with normal B cells. Unexpectedly, metabolic pathways, namely cholesterol synthesis and adipogenesis, are also enhanced by CD5. Conversely, CD5 inhibited genes involved in RNA splicing and processing, ribosome biogenesis, proteasome, and CD80 and CD86 Ags, whose expression is low in CLL. Comparison of CD5- vs tailless CD5-transfected cells further demonstrated the role of CD5 phosphorylation in the regulation of selected genes. These results support a model where CLL cells are chronically stimulated, leading to CD5 activation and cell survival. In addition to CD5 itself, we point to several CD5-induced genes as potential therapeutic targets.

GILZ expression in human dendritic cells redirects their maturation and prevents antigen-specific T lymphocyte response.

Interleukin (IL)-10 and glucocorticoids (GCs) inhibit the ability of antigen-presenting dendritic cells (DCs) to stimulate T lymphocytes. We show that induction of GILZ (GC-induced leucine zipper) is involved in this phenomenon. IL-10, dexamethasone (DEX), and transforming growth factor (TGF)beta stimulate GILZ production in human immature DCs derived from monocytes and from CD34+ cells. GILZ is necessary and sufficient for DEX, IL-10, and TGFbeta modulation of CD80, CD83, CD86, immunoglobulin-like transcript (ILT)-3, and B7-H1 expression by DCs, and alteration of DC functions. GILZ stimulates the production of IL-10 by immature DCs and prevents the production of inflammatory chemokines by CD40L-activated DCs. In contrast, GILZ does not prevent CD40 ligand-mediated inhibition of phagocytosis, indicating that it affects some but not all aspects of DC maturation. GILZ prevents DCs from activating antigen-specific T lymphocyte responses. Administration of GCs to patients stimulates GILZ expression in their circulating antigen-presenting cells, and this contributes to the weak lymphocyte responses of GC-treated patients. Thus, regulation of GILZ expression is an important factor determining the decision of DCs whether or not to stimulate T lymphocytes, and IL-10, GCs, and TGFbeta share this mechanism for influencing DC functions and the balance between immune response and tolerance.

Serum leptin in patients with alcoholic liver disease.

BACKGROUND: The mechanisms by which overweight makes the liver more susceptible to alcoholic liver injury remain to be determined. Therefore, we conducted the following studies to further elucidate the role of leptin in the pathogenesis of steatosis and cirrhosis caused by chronic alcohol consumption in human beings. METHODS: Two-hundred nine consecutive patients with alcoholic liver disease were studied. Serum leptin concentrations were measured by using radioimmunoassay, and the relationships between serum leptin level and liver lesions were studied. Statistical analysis used logistic regressions. RESULTS: When serum leptin, serum cholesterol, and body mass index (BMI) were considered together in the multiple logistic regression analysis, compared with patients with severe steatosis, serum leptin remains significantly lower in patients without steatosis (p<0.05) and in patients with mild or moderate steatosis (p<0.05). When age, serum leptin, serum cholesterol, and steatosis grade were considered together in the logistic regression analysis, serum leptin (p<0.01) and age (p<0.02) were positively and independently correlated with the presence of cirrhosis. After BMI introduction in the statistical model, serum leptin was no more correlated with the presence of cirrhosis. CONCLUSION: In patients with alcoholic liver disease, serum leptin is independently correlated with steatosis grade and might play an important role in severity of fibrosis as fatty liver is more vulnerable than normal liver to factors that lead to fibrosis.

Interleukin-10 modulates the sensitivity of peritoneal B lymphocytes to chemokines with opposite effects on stromal cell-derived factor-1 and B-lymphocyte chemoattractant.

Interleukin-10 (IL-10) is constitutively produced by peritoneal B1a lymphocytes, and stromal cell-derived factor-1 (SDF-1) by mesothelial cells. Independent studies have shown that both IL-10 and SDF-1 are involved in the persistence of the peritoneal B-lymphocyte compartment. This study shows that IL-10 and SDF-1 act in synergy on peritoneal B lymphocytes. Indeed, autocrine production of IL-10 was absolutely required for all effects of SDF-1 on these cells, including increased proliferation, survival, and chemotaxis. Moreover, adding IL-10 to peritoneal B lymphocytes increased the effects of SDF-1. Neither IL-5, IL-6, nor IL-9 affected the response of peritoneal B lymphocytes to SDF-1. IL-10 was chemokinetic for peritoneal B lymphocytes, increasing their random mobility. It also potentiated the SDF-1-induced reorganization of the cytoskeleton without affecting CXCR4 gene expression by peritoneal B lymphocytes. Despite its chemokinetic properties, IL-10 abolished the migration of peritoneal B lymphocytes in response to B-lymphocyte chemoattractant (BLC), a chemokine targeting B lymphocytes to lymphoid organ follicles. The ability of B1a lymphocytes to produce IL-10 constitutively, combined with the opposite effects of this cytokine on the responses to SDF-1 and BLC, may account for the selective accumulation of B1 lymphocytes in body cavities.

Effects of exogenous IL-2 administration on the homeostasis of CD4+ T lymphocytes.

IL-2 is currently used in HIV-infected patients to treat CD4+ T lymphopenia. In order to document a mechanism accounting for its capacity to restore immune function, we studied the effects of IL-2 administration in mice. IL-2 treatment of C57BL/6 mice for 4 days leads to a transient accumulation of CD4+ T lymphocytes. Whereas memory and activated CD4+ T lymphocytes accumulate after IL-2 treatment in both lymphoid and nonlymphoid organs, naive CD4+ T cells only accumulate in the former. IL-2 transiently increases CD4+ T lymphocyte numbers in lymphopenic IL-7(-/-) mice. Studies in T-cell-reconstituted Rag(-/-) gamma c(-/-) mice and in thymectomized mice demonstrated that IL-2 acts directly on peripheral CD4+ T lymphocytes. In vivo labeling of thymocytes showed that IL-2 also stimulates the release of CD4+ thymocytes from the thymus. Therefore, IL-2 treatment acts centrally and peripherally to increase the size of the naive CD4+ T lymphocyte compartment. This dual activity of IL-2 treatment may influence the quality of restoration of this compartment, especially regarding the ability to reconstitute a normal T lymphocyte repertoire.

Role of the chemokine stromal cell-derived factor 1 in autoantibody production and nephritis in murine lupus.

In normal mice, stromal cell-derived factor 1 (SDF-1/CXCL12) promotes the migration, proliferation, and survival of peritoneal B1a (PerB1a) lymphocytes. Because these cells express a self-reactive repertoire and are expanded in New Zealand Black/New Zealand White (NZB/W) mice, we tested their response to SDF-1 in such mice. PerB1a lymphocytes from NZB/W mice were exceedingly sensitive to SDF-1. This greater sensitivity was due to the NZB genetic background, it was not observed for other B lymphocyte subpopulations, and it was modulated by IL-10. SDF-1 was produced constitutively in the peritoneal cavity and in the spleen. It was also produced by podocytes in the glomeruli of NZB/W mice with nephritis. The administration of antagonists of either SDF-1 or IL-10 early in life prevented the development of autoantibodies, nephritis, and death in NZB/W mice. Initiation of anti-SDF-1 mAb treatment later in life, in mice with established nephritis, inhibited autoantibody production, abolished proteinuria and Ig deposition, and reversed morphological changes in the kidneys. This treatment also counteracted B1a lymphocyte expansion and T lymphocyte activation. Therefore, PerB1a lymphocytes are abnormally sensitive to the combined action of SDF-1 and IL-10 in NZB/W mice, and SDF-1 is key in the development of autoimmunity in this murine model of lupus.

Synthesis of glucocorticoid-induced leucine zipper (GILZ) by macrophages: an anti-inflammatory and immunosuppressive mechanism shared by glucocorticoids and IL-10.

Glucocorticoids and interleukin 10 (IL-10) prevent macrophage activation. In murine lymphocytes, glucocorticoids induce expression of glucocorticoid-induced leucine zipper (GILZ), which prevents the nuclear factor kappaB (NF-kappaB)-mediated activation of transcription. We investigated whether GILZ could account for the deactivation of macrophages by glucocorticoids and IL-10. We found that GILZ was constitutively produced by macrophages in nonlymphoid tissues of humans and mice. Glucocorticoids and IL-10 stimulated the production of GILZ by macrophages both in vitro and in vivo. Transfection of the macrophagelike cell line THP-1 with the GILZ gene inhibited the expression of CD80 and CD86 and the production of the proinflammatory chemokines regulated on activation normal T-cell expressed and secreted (CCL5) and macrophage inflammatory protein 1alpha (CCL3). It also prevented toll-like receptor 2 production induced by lipopolysaccharide, interferongamma, or an anti-CD40 mAb, as well as NF-kappaB function. In THP-1 cells treated with glucocorticoids or IL-10, GILZ was associated with the p65 subunit of NF-kappaB. Activated macrophages in the granulomas of patients with Crohn disease or tuberculosis do not produce GILZ. In contrast, GILZ production persists in tumor-infiltrating macrophages in Burkitt lymphomas. Therefore, GILZ appears to play a key role in the anti-inflammatory and immunosuppressive effects of glucocorticoids and IL-10. Glucocorticoid treatment stimulates GILZ production, reproducing an effect of IL-10, a natural anti-inflammatory agent. The development of delayed-type hypersensitivity reactions is associated with the down-regulation of GILZ gene expression within lesions. In contrast, the persistence of GILZ gene expression in macrophages infiltrating Burkitt lymphomas may contribute to the failure of the immune system to reject the tumor.