Hereditary angioedema: first report of the Brazilian registry and challenges.

BACKGROUND: Hereditary Angio-oedema (HAE) is a serious medical condition caused by a rare autosomal dominant genetic disorder, in which C1 inhibitor (C1-INH) function is reduced. There is no organized information on the HAE patient population in Brazil. OBJECTIVE: The Brazilian Registry was established to disseminate diagnostic access, and to better understand the main features of the disease in our country and its clinical impact. METHODS: A questionnaire was prepared and sent to specialists. The completed questionnaires were forwarded to the coordinating site and then entered into the Registry. Samples from patients with an unconfirmed diagnosis were tested for C1 inhibitor and C4 levels. RESULTS: From 2006 to 2010, 210 patients (133 females; mean age, 30 ±17 years) were included. The median age of onset of symptoms and age at diagnosis were 6.5 and 21 years, respectively; 80.9% of the patients had subcutaneous oedema, 54% gastrointestinal and 35.7% respiratory symptoms (21% had laryngeal oedema). Laparotomy due to the disease was performed in 6.2% of the patients. The majority of patients had Type I HAE of moderate severity. Twenty-seven per cent did not receive treatment; 53% were treated with danazol alone. CONCLUSION: A paucity of patients with Type II HAE and a high frequency of laparotomy were observed, highlighting the need for better diagnosis in Brazil. HAE related educational activities, improved diagnosis and access to available therapy are needed in Brazil.

Characterization of the cellular immunity in patients presenting extensive dermatophytoses due to Trichophyton rubrum.

Dermatophytes invade the stratum corneum of the skin and other keratinized tissues such as hair and nails, and Trichophyton rubrum causes approximately 80% of cutaneous mycoses in humans. To evaluate the cellular immune response of patients with extensive dermatophytosis caused by T. rubrum, we evaluated lymphocyte populations, the lymphoproliferative response to: phytohaemagglutinin (PHA); anti-CD3 (OKT3); and pokeweed mitogen (PWM), Candida sp. (CMA), an extract of T. rubrum, and the main fungal epitope TriR2 (T). We also evaluated interleukin (IL)-4, IL-10, IL-12 and IFN-γ after stimulation by PHA, CMA and TriR2. The immunophenotyping showed no differences between patients and controls. The lymphoproliferation test showed significant differences between the groups stimulated by PWM and CMA, as well as against TriR2, being significantly higher for the control group. Conversely, there were similar results for the groups after stimulation by the extract. The cytokines' quantification showed a significant difference between the groups only for IFN-γ stimulated by PHA and TriR2. We can conclude that the fungal extract can stimulate lymphoproliferation by both groups' lymphocytes. However, the response to Tri r2 was more specific. We showed that some patients with extensive dermatophytosis have normal cellular response, recognising both the extract and TriR2.

Molecular characterization of patients with X-linked Hyper-IgM syndrome: description of two novel CD40L mutations.

Type 1, X-linked Hyper-IgM syndrome (HIGM1) is caused by mutations in the gene encoding the CD154 protein, also known as CD40 ligand (CD40LG). CD40L is expressed in activated T cells and interacts with CD40 receptor expressed on B lymphocytes and dendritic cells. Affected patients present cellular and humoral immune defects, with infections by intracellular, opportunistic and extracellular pathogens. In the present study we investigated the molecular defects underlying disease in four patients with HIGM1. We identified four distinct CD40L mutations, two of them which have not been previously described. P1 harboured the novel p.G227X mutation which abolished CD40L expression. P2 had a previously described frame shift deletion in exon 2 (p.I53fsX65) which also prevented protein expression. P3 demonstrated the previously known p.V126D change in exon 4, affecting the TNF homology (TNFH) domain. Finally, P4 evidenced the novel p.F229L mutation also located in the TNFH domain. In silico analysis of F229L predicted the change to be pathological, affecting the many hydrophobic interactions of this residue. Precise molecular diagnosis in HIGM syndrome allows reliable detection of carriers, making genetic counselling and prenatal diagnosis possible.

Deficiency of the human complement regulatory protein factor H associated with low levels of component C9.

We identified a 4-year-old Brazilian boy from a family of Japanese descent and history of consanguinity, who suffered from severe recurrent pneumonia. He carries factor H (FH) deficiency associated with reduced levels of component C9 and low serum levels of C3 and factor B. His mother also presented low levels of these proteins and factor I, while his father and sister had only lower levels of FH. Western blot assays confirmed the complete absence of FH and FHL-1 polypeptides in this patient. Sequencing of the proband's FH cDNA revealed a homozygous G453A substitution, encoding an Arg(127)His change. His mother, father and sister are heterozygous for this substitution. Despite the absence of FH in the plasma, this protein was detected in the patient's fibroblasts, suggesting that Arg(127) may be important for FH secretion. Low concentrations of C9 were detected in the proband serum but no mutations in the patient's C9 gene or promoter have been identified, suggesting that this is a consequence of uncontrolled complement activation and high C9 consumption.

Primary immune deficiency disorders presenting as autoimmune diseases: IPEX and APECED.

BACKGROUND: Several primary immune deficiency disorders are associated with autoimmunity and malignancy, suggesting a state of immune dysregulation. The concept of immune dysregulation as a direct cause of autoimmunity in primary immune deficiency disorders (PIDDs) has been strengthened by the recent discovery of distinct clinical entities linked to single-gene defects resulting in multiple autoimmune phenomena including immune dysregulation, polyendocrinopathy, enteropathy and X-linked (IPEX) syndrome, and autoimmune polyendocrinopathy, candidiasis and ectodermal dystrophy (APECED) syndrome. CONCLUSION: Reviewing recent advances in our understanding of the small subgroup of PIDD patients with defined causes for autoimmunity may lead to the development of more effective treatment strategies for idiopathic human autoimmune diseases.

Immunological analysis in paediatric HIV patients at different stages of the disease.

There are only few clinical studies on complement in well-defined (or characterized) paediatric HIV patients. Aim of this study was to evaluate the complement system and immunoglobulins in HIV-infected children and to correlate data to stage of disease. Blood samples of 127 HIV-infected children (11-134 months; 62 male : 65 female) were collected in order to evaluate humoral immunity. The patients were classified according to CDC clinical (N-asymptomatic; A-mild symptoms such as common recurrent infections; B-moderate symptoms such as Candidiasis and herpes infections, meningitis, sepsis and anaemia; C-severe symptoms such as opportunistic infections and neoplasia) and with respect to immunological criteria (T CD4(+) cell count). Analysis of complement system included the classical (CH50), alternative (APH50) pathway activities and plasma concentrations of mannan-binding lectin (MBL), of the C4 allotypic variants C4A and C4B. (ELISA), and of the C3 split product C3d (rocket immunoeletrophoresis). Immunodiagnosis also included CD4(+) and CD8(+) lymphocyte count and immunoglobulin concentrations. Complement activation and consumption was observed in all patients correlating with disease activity. Activated classical and alternative pathways and elevated C3d were significantly correlated with immunologic category 3. C3d levels were also significantly correlated with immunologic category 1. Undetectable CH50 and APH50 were found in two (group C) and 10 patients (n = 2, A = 2, B = 2, C = 4), respectively. Low MBL values were found in 13/127 but without correlation to disease severity. Undetectable C4B levels were observed in three patients, favouring the diagnosis of a complete deficiency. Although not related to clinical symptomatology, a strong ongoing complement activation can be observed in all stages of HIV infection. In contrast to earlier reports MBL could not be considered as a risk factor for HIV.

Detection of influenza, parainfluenza, adenovirus and respiratory syncytial virus during asthma attacks in children older than 2 years old.

BACKGROUND: Viral upper respiratory tract infections (URTI) have been correlated with the onset of asthma attacks in children and viral identification was reported in 14-49 % of nasal samples. The aim of the present study was to detect influenza, parainfluenza, adenovirus and respiratory syncytial virus (RSV) in older children during acute asthma attacks. METHODS: A total of 104 children (2-14 years) were included in four groups: group I: asthmatics with acute attack and URTI; group II: asthmatics without URTI (group I children, 30 days later); group III: non-asthmatics with URTI; group IV: non-asthmatic, asymptomatic children. A diagnosis of URTI was considered when (3 symptoms (cough and/or sneeze, nasal obstruction, hypertrophy of turbinates, pain and/or retropharynx hyperemia, headache and fever) in asthmatics and at least 2 symptoms in non-asthmatics were present, starting within 7 days. Samples of nasal mucosa cells (n = 123) were collected, and culture and indirect immunofluorescence were carried out to identify respiratory syncytial virus, adenovirus, influenza A and B, parainfluenza 1,2 and 3 and rhinovirus. RESULTS: Viral identification rates were higher in the asthmatic groups: 13.9 % in group I, 11.1 % in group II; 2.8 % in group III and 0 in group IV. The following viruses were identified: RSV 2/36, rhinovirus 1/36, adenovirus 1/36 and parainfluenzae 1/36 in group I; adenovirus 2/18 in group II; RSV 1/36 in group III. CONCLUSIONS: The rate of viral identification was higher in asthmatic children, whether symptomatic or not, suggesting a possible susceptibility to viral infections. Virus could also be a triggering factor in attacks, although it is not the most preponderant in older children.

Characterization of the cellular immune function of patients with chronic mucocutaneous candidiasis.

Chronic mucocutaneous candidiasis (CMC) is a rare syndrome characterized by persistent and refractory infections of the skin, nails and mucosal tissues by yeasts of the genus Candida. Defects in the cellular limb of the immune system are well documented in CMC patients, but non-specific immune defects, such as myeloperoxidase deficiency or phagocyte chemotaxis disorders, have also been described. Nonetheless, the underlying defect(s) remains poorly understood, and further studies are required. We studied eight CMC patients without endocrinopathies, who showed (i) low normal proliferative response to phytohaemagglutinin (PHA), (ii) partially defective response to pokeweed mitogen (PWM), and (iii) impaired response to Candida and PPD antigens. Furthermore, peripheral blood mononuclear cells (PBMC) from CMC patients produced lower levels of type-1 cytokines (IL-2 and interferon-gamma) in response to Candida antigens, compared with control individuals. Conversely, we did not observe an enhancement of IL-4 and IL-10 in the patients, suggesting that, even though Th1 cytokines are decreased, the Th2 response is not increased in CMC. Nevertheless, the synthesis of these cytokines was normal when induced by PHA. We also observed an increased antigen-induced apoptosis in lymphocytes from the patients compared with controls, and this applied both to Candida and PPD antigens. Lastly, innate immunity defects were investigated. We observed an impairment of natural killer activity against K-562 target cells in half of the studied patients. These findings corroborate the extensive clinical and laboratory variability of CMC, which requires further studies on a larger number of patients to be better understood.