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Patients with chronic mucocutaneous candidiasis (CMC) have an unknown primary immune defect and are unable to clear infections with the yeast Candida. CMC includes patients with AIRE gene mutations who have autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), and patients without known mutations. CMC patients have dysregulated cytokine production, suggesting that defective expression of pattern recognition receptors (PRRs) may underlie disease pathogenesis. In 29 patients with CMC (13 with APECED) and controls, we assessed dendritic cell (DC) subsets and monocyte Toll-like receptor (TLR) expression in blood. We generated and stimulated monocyte-derived (mo)DCs with Candida albicans, TLR-2/6 ligand and lipopolysaccharide and assessed PRR mRNA expression by polymerase chain reaction [TLR-1-10, Dectin-1 and -2, spleen tyrosine kinase (Syk) and caspase recruitment domain (CARD) 9] in immature and mature moDCs. We demonstrate for the first time that CMC patients, with or without APECED, have normal blood levels of plasmocytoid and myeloid DCs and monocyte TLR-2/TLR-6 expression. We showed that in immature moDCs, expression levels of all PRRs involved in anti-Candida responses (TLR-1, -2, -4, -6, Dectin-1, Syk, CARD9) were comparable to controls, implying that defects in PRR expression are not responsible for the increased susceptibility to Candida infections seen in CMC patients. However, as opposed to healthy controls, both groups of CMC patients failed to down-regulate PRR mRNA expression in response to Candida, consistent with defective DC maturation, as we reported recently. Thus, impaired DC maturation and consequent altered regulation of PRR signalling pathways rather than defects in PRR expression may be responsible for inadequate Candida handling in CMC patients.

Patients with chronic mucocutaneous candidiasis (CMC) suffer persistent infections with the yeast Candida. CMC includes patients with autoimmune regulator (AIRE) gene mutations who have autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), and patients without known mutations. CMC patients have dysregulated cytokine production, and dendritic cells (DCs), as central orchestrators, may underlie pathogenic disease mechanisms. In 29 patients with CMC (13 with APECED) and controls, we generated monocyte-derived DCs, stimulated them with Candida albicans, Toll-like receptor-2/6 ligand and lipopolysaccharide to assess cytokine production [interleukin (IL)-12p70, IL-23, interferon (IFN)-gamma, IL-2, tumour necrosis factor (TNF)-alpha, IL-6, transforming growth factor-beta, IL-10, IL-5, IL-13] and cell-surface maturation marker expression (CD83, CD86, human leucocyte antigen D-related). In both APECED and non-APECED CMC patients, we demonstrate impairment of DC function as evidenced by altered cytokine expression profiles and DC maturation/activation: (1) both groups over-produce IL-2, IFN-gamma, TNF-alpha and IL-13 and demonstrate impaired DC maturation. (2) Only non-APECED patients showed markedly decreased Candida-stimulated production of IL-23 and markedly increased production of IL-6, suggesting impairment of the IL-6/IL-23/T helper type 17 axis. (3) In contrast, only APECED patients showed DC hyperactivation, which may underlie altered T cell responsiveness, autoimmunity and impaired response to Candida. We demonstrate different pathogenic mechanisms on the same immune response pathway underlying increased susceptibility to Candida infection in these patients.

More than 11 genetic causes of severe combined immunodeficiency (SCID) have been identified, affecting development and/or function of T lymphocytes, and sometimes B lymphocytes and natural killer (NK) cells. Deletion of 22q11.2 is associated with immunodeficiency, although less than 1% of cases are associated with T-B + NK + SCID phenotype. Severe immunodeficiency with CHARGE syndrome has been noted only rarely Omenn syndrome is a rare autosomal recessive form of SCID with erythroderma, hepatosplenomegaly, lymphadenopathy and alopecia. Hypomorphic recombination activating genes 1 and 2 mutations were first described in patients with Omenn syndrome. More recently, defects in Artemis, RMRP, IL7Ralpha and common gamma chain genes have been described. We describe four patients with mutations in CHD7, who had clinical features of CHARGE syndrome and who had T-B + NK + SCID (two patients) or clinical features consistent with Omenn syndrome (two patients). Immunodeficiency in patients with DiGeorge syndrome is well recognized--CHARGE syndrome should now be added to the causes of T-B + NK + SCID, and mutations in the CHD7 gene may be associated with Omenn-like syndrome.

There are no epidemiological studies from the British Isles of chronic granulomatous disease, characterized by recurrent, life-threatening bacterial and fungal infections and inflammatory sequelae. Patients were enrolled in a national registry and medical records were analysed. Of 94 subjects, 69 had X-linked disease, 16 had autosomal recessive disease and nine were unknown. Prevalence was 7.5/million for 1990-99 and 8.5/million for 1980-89. Suppurative adenitis, abscesses and pneumonia presented commonly. Twenty-three of 30 patients who underwent high resolution computerized tomography had chronic respiratory disease. Inflammatory sequelae included bowel stricture and urogenital tract granulomata. Growth failure was common; 75% of those measured were below the population mean. All patients received prophylactic antibiotics and 93% anti-fungal prophylaxis. Interferon gamma was used to treat infection, but rarely as prophylaxis. Despite prophylaxis, estimated survival was 88% at 10 years but 55% at age 30 years. Morbidity remains significant, severe infectious complications common. Curative treatments including stem cell transplantation should be considered for patients with frequent or serious complications.

This observational study describes the ranges observed for lymphocyte subsets for significantly preterm infants (<32 weeks) in the first year of life, measured by single platform flow cytometry and compared to identically determined subsets in term infants. After ethical approval 39 term and 28 preterm infants had lymphocyte subset analysis before and after their primary immunization series. Median values with 5th and 95th percentiles of absolute counts and percentages are presented for total lymphocytes, T cells, NK cells, B cells, cytotoxic T cells, helper T cells, dual positive T cells, activated T cells, activated T helper cells (including T regulatory cells), pan memory T cells, pan naive T cells, memory helper T cells, naive helper T cells and the T helper/suppressor ratio. The lymphocyte profile of the preterm infants differed from that of the term infants.

Hereditary periodic fever syndromes comprise a group of distinct disease entities linked by the defining feature of recurrent febrile episodes. Hyper IgD with periodic fever syndrome (HIDS) is caused by mutations in the mevalonate kinase (MVK) gene. The mechanisms by which defects in the MVK gene cause febrile episodes are unclear and there is no uniformly effective treatment. Mutations of the TNFRSF1A gene may also cause periodic fever syndrome (TRAPS). Treatment with the TNFR-Fc fusion protein, etanercept, is effective in some patients with TRAPS, but its clinical usefulness in HIDS has not been reported. We describe a 3-year-old boy in whom genetic screening revealed a rare combination of two MVK mutations producing clinical HIDS as well as a TNFRSF1A P46L variant present in about 1% of the population. In vitro functional assays demonstrated reduced receptor shedding in proband's monocytes. The proband therefore appears to have a novel clinical entity combining Hyper IgD syndrome with defective TNFRSF1A homeostasis, which is partially responsive to etanercept.

Fas-mediated apoptosis may be one of the effector pathways leading to the elimination of virus-infected cells. Cytomegalovirus (CMV) infection in two brothers with Fas deficiency associated with autoimmunity and benign lymphoproliferation (ALPS) provided a unique opportunity to study the clinical course of CMV infection in children with defective apoptosis. The clinical courses of two brothers with autosomal dominant ALPS who were infected with CMV in the neonatal period are described. CMV was detected from throat and urine culture from the brothers. ALPS was confirmed by in vitro anti-CD95 MoAb-induced T lymphocyte apoptosis assay and subsequent sequencing and identification of mutations in the Fas gene. A de novo mutation in the Fas gene, leading to a truncated cytoplasmic Fas product, was associated with autosomal dominant ALPS in a mother and her two sons. Both boys had evidence of CMV infection acquired early in infancy which cleared by the age of 2-3 years. There were no neurodevelopmental sequelae. The natural history of CMV infection in two infants with ALPS was similar to that described in normal children.

Patients with chronic mucocutaneous candidiasis (CMC) succumb to persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been repeatedly reported while antibody responses were mostly found to be normal. The underlying defect remains poorly understood. It has recently been shown that CMC patients are also susceptible to infections with encapsulated bacteria, and may have associated IgG2 and IgG4 deficiency. Our previous studies demonstrated altered cytokine production in CMC patients. As cytokines can influence production and isotype of specific antibody, in 10 patients with CMC we measured the levels and isotype distribution of serum antibodies to Candida antigens (CAg), pneumococcal polysaccharide (PPS) and tetanus toxoid (TT) antigens. Peripheral blood lymphocytes were also stimulated in culture and the antibodies made in vitro were measured. Our data demonstrated that in vivo, CMC patients had very high levels of IgG and IgA CAg-specific antibodies. CAg-specific and PPS-specific IgG1 was markedly higher than in controls. Children but not adults with CMC had significantly lower levels of IgG2-specific antibody to CAg and PPS compared with age-matched controls. Patients had significantly higher levels of IgG3-specific antibody to all three antigens tested. These findings were in accordance with increased total IgG and IgG3 levels seen in CMC patients. In vitro, CMC patients, particularly children, did not respond as frequently to antigen stimulation as did their healthy controls. The level of specific antibody produced was also lower to all antigens tested, as was the amount of total immunoglobulins following antigenic and particularly mitogenic stimulation. Addition of interferon-alpha (IFN-alpha) or IFN-gamma to cultures had variable, sometimes marked, effects. Our results demonstrate that CMC patients manifest subtle alterations in specific antibody responses to CAg, PPS and TT, which are most pronounced in children. This may relate to altered cytokine production also seen in these patients.

Patients with chronic mucocutaneous candidiasis (CMC) present with persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been documented in CMC patients, but the defect remains poorly understood. The importance of Th1 cytokines in resistance and Th2 in susceptibility to Candida infections has recently been demonstrated in murine models. In our studies we evaluated production of IL-2 and IFN-gamma (markers of Th1 type responses) as well as IL-4 and IL-6 (Th2 type markers) following stimulation with two kinds of Candida antigens (CAgs), polysaccharide antigens, tetanus toxoid and pokeweed mitogen. Our results demonstrate that CMC patients have impaired cytokine production upon in vitro stimulation with CAgs resulting in low or absent IL-2, increased IL-6 and either absent or increased IFN-gamma production. Cytokine production following stimulation by other antigens was unaltered. The overall cytokine-producing capacity assessed through mitogen stimulation was also intact. Addition of IFN-alpha or IFN-gamma to culture in an attempt to modify cytokine production did not have significant effects. Levels of soluble IL-6 receptors were not increased and could not account for increased IL-6 production. Our studies support the hypothesis that Candida antigens trigger a predominantly Th2 instead of a Th1 cytokine response in patients with CMC.

As part of a study designed to reveal information about molecular features of allergenic food proteins after absorption from the gut the specificity of antibodies in normal human serum to hen's egg ovalbumin was investigated using ELISA techniques. Preliminary investigations with monoclonal antibodies and hyperimmune rabbit antiserum specific for ovalbumin in its native and denatured form established that the molecule underwent an extensive conformational change on adsorption to polyvinyl chloride microtitre plates. The native conformation could be retained by using antibodies to couple the protein to the surface. Serum from 90% of healthy adult human donors contained IgG antibodies to ovalbumin. In nearly all cases the antibodies were specific predominantly for the native molecule and could not be absorbed with denatured ovalbumin or peptides prepared from it by cleavage with cyanogen bromide or trypsin. Antibodies to denatured ovalbumin were detected in most sera but at very low levels and were preferentially absorbed by the homologous antigen; peptides and native ovalbumin showing variable absorptive activity. Thus, although ovalbumin is ingested largely in a denatured form, the serum antibody response is stimulated mainly by topographic epitopes of the native molecule.