Recomendaciones para el cuidado, prevención de infecciones y quimioprofilaxis en los errores innatos de la inmunidad / Recommendations for care, prevention of infections and chemoprophylaxis in inborn errors of immunity

Los errores innatos de la inmunidad (EII), antes llamados inmunodeficiencias primarias (IDP), son un grupo heterogéneo de trastornos genéticos con defectos en uno o más componentes del sistema inmune. Los pacientes afectados por EII presentan aumentada susceptibilidad a microorganismos únicos o múltiples que se manifestará con infecciones recurrentes de diferente tipo y gravedad dependiendo del tipo de la localización del defecto. La prevención de infecciones es uno de los pilares fundamentales en el abordaje integral de los pacientes con EII. En este trabajo se resumen las conclusiones consensuadas en el Grupo de Trabajo de Inmunología Pediátrica de la Sociedad Argentina de Pediatría, sobre la base de la revisión de la evidencia disponible, respecto a los principios esenciales para el cuidado, la prevención de infecciones y la quimioprofilaxis en los errores innatos de la inmunidad para la orientación del pediatra y especialista dedicados al seguimiento de estas enfermedades.

Inborn errors of immunity, previously named primary immunodeficiency are a heterogeneous group of genetic defects of different components of the immune system. Patients present high susceptibility to an only or several microorganisms, developing recurrent infections; the severity is related to the specific genetic type of immunity defect. The main strategy on the management of these illness is the prevention of infections. These consensus guidelines made by the Pediatric Immunology Work Group of Sociedad Argentina de Pediatría, givese main approaches of infection prevention in order to provide a useful tool for all practitioners who are involved in the management of these patients, based on scientific evidence and broad consensus of a specialized panel expert.

[Recommendations for care, prevention of infections and chemoprophylaxis in inborn errors of immunity]. / Recomendaciones para el cuidado, prevención de infecciones y quimioprofilaxis en los errores innatos de la inmunidad.

Inborn errors of immunity, previously named primary immunodeficiency are a heterogeneous group of genetic defects of different components of the immune system. Patients present high susceptibility to an only or several microorganisms, developing recurrent infections; the severity is related to the specific genetic type of immunity defect. The main strategy on the management of these illness is the prevention of infections. These consensus guidelines made by the Pediatric Immunology Work Group of Sociedad Argentina de Pediatría, givese main approaches of infection prevention in order to provide a useful tool for all practitioners who are involved in the management of these patients, based on scientific evidence and broad consensus of a specialized panel expert..

Los errores innatos de la inmunidad (EII), antes llamados inmunodeficiencias primarias (IDP), son un grupo heterogéneo de trastornos genéticos con defectos en uno o más componentes del sistema inmune. Los pacientes afectados por EII presentan aumentada susceptibilidad a microorganismos únicos o múltiples que se manifestará con infecciones recurrentes de diferente tipo y gravedad dependiendo del tipo de la localización del defecto. La prevención de infecciones es uno de los pilares fundamentales en el abordaje integral de los pacientes con EII. En este trabajo se resumen las conclusiones consensuadas en el Grupo de Trabajo de Inmunología Pediátrica de la Sociedad Argentina de Pediatría, sobre la base de la revisión de la evidencia disponible, respecto a los principios esenciales para el cuidado, la prevención de infecciones y la quimioprofilaxis en los errores innatos de la inmunidad para la orientación del pediatra y especialista dedicados al seguimiento de estas enfermedades.

CD40 Ligand Deficiency in Latin America: Clinical, Immunological, and Genetic Characteristics.

CD40 ligand (CD40L) deficiency is a rare inborn error of immunity presenting with heterogeneous clinical manifestations. While a detailed characterization of patients affected by CD40L deficiency is essential to an accurate diagnosis and management, information about this disorder in Latin American patients is limited. We retrospectively analyzed data from 50 patients collected by the Latin American Society for Immunodeficiencies registry or provided by affiliated physicians to characterize the clinical, laboratory, and molecular features of Latin American patients with CD40L deficiency. The median age at disease onset and diagnosis was 7 months and 17 months, respectively, with a median diagnosis delay of 1 year. Forty-seven patients were genetically characterized revealing 6 novel mutations in the CD40LG gene. Pneumonia was the most common first symptom reported (66%). Initial immunoglobulin levels were variable among patients. Pneumonia (86%), upper respiratory tract infections (70%), neutropenia (70%), and gastrointestinal manifestations (60%) were the most prevalent clinical symptoms throughout life. Thirty-five infectious agents were reported, five of which were not previously described in CD40L deficient patients, representing the largest number of pathogens reported to date in a cohort of CD40L deficient patients. The characterization of the largest cohort of Latin American patients with CD40L deficiency adds novel insights to the recognition of this disorder, helping to fulfill unmet needs and gaps in the diagnosis and management of patients with CD40L deficiency.

Partial growth hormone insensitivity and dysregulatory immune disease associated with de novo germline activating STAT3 mutations.

Germinal heterozygous activating STAT3 mutations represent a novel monogenic defect associated with multi-organ autoimmune disease and, in some cases, severe growth retardation. By using whole-exome sequencing, we identified two novel STAT3 mutations, p.E616del and p.C426R, in two unrelated pediatric patients with IGF-I deficiency and immune dysregulation. The functional analyses showed that both variants were gain-of-function (GOF), although they were not constitutively phosphorylated. They presented differences in their dephosphorylation kinetics and transcriptional activities under interleukin-6 stimulation. Both variants increased their transcriptional activities in response to growth hormone (GH) treatment. Nonetheless, STAT5b transcriptional activity was diminished in the presence of STAT3 GOF variants, suggesting a disruptive role of STAT3 GOF variants in the GH signaling pathway. This study highlights the broad clinical spectrum of patients presenting activating STAT3 mutations and explores the underlying molecular pathway responsible for this condition, suggesting that different mutations may drive increased activity by slightly different mechanisms.

Mechanisms of genotype-phenotype correlation in autosomal dominant anhidrotic ectodermal dysplasia with immune deficiency.

BACKGROUND: Autosomal dominant anhidrotic ectodermal dysplasia with immune deficiency (AD EDA-ID) is caused by heterozygous point mutations at or close to serine 32 and serine 36 or N-terminal truncations in IκBα that impair its phosphorylation and degradation and thus activation of the canonical nuclear factor κ light chain enhancer of activated B cells (NF-κB) pathway. The outcome of hematopoietic stem cell transplantation is poor in patients with AD EDA-ID despite achievement of chimerism. Mice heterozygous for the serine 32I mutation in IκBα have impaired noncanonical NF-κB activity and defective lymphorganogenesis. OBJECTIVE: We sought to establish genotype-phenotype correlation in patients with AD EDA-ID. METHODS: A disease severity scoring system was devised. Stability of IκBα mutants was examined in transfected cells. Immunologic, biochemical, and gene expression analyses were performed to evaluate canonical and noncanonical NF-κB signaling in skin-derived fibroblasts. RESULTS: Disease severity was greater in patients with IκBα point mutations than in those with truncation mutations. IκBα point mutants were expressed at significantly higher levels in transfectants compared with truncation mutants. Canonical NF-κB-dependent IL-6 secretion and upregulation of the NF-κB subunit 2/p100 and RELB proto-oncogene, NF-κB subunit (RelB) components of the noncanonical NF-κB pathway were diminished significantly more in patients with point mutations compared with those with truncations. Noncanonical NF-κB-driven generation of the transcriptionally active p100 cleavage product p52 and upregulation of CCL20, intercellular adhesion molecule 1 (ICAM1), and vascular cell adhesion molecule 1 (VCAM1), which are important for lymphorganogenesis, were diminished significantly more in LPS plus α-lymphotoxin ß receptor-stimulated fibroblasts from patients with point mutations compared with those with truncations. CONCLUSIONS: IκBα point mutants accumulate at higher levels compared with truncation mutants and are associated with more severe disease and greater impairment of canonical and noncanonical NF-κB activity in patients with AD EDA-ID.

Infección pulmonar por Arthrographis kalrae en un paciente con enfermedad granulomatosa crónica / Pulmonary infection by Arthrographis kalrae in patient with chronic granulomatous disease

Antecedentes: Arthrographis kalrae es un hongo hialino de crecimiento lento que, en su desarrollo, forma artroconidios. Es un patógeno oportunista que causa infecciones en personas inmunocomprometidas e inmunocompetentes, y ha sido aislado muy raramente en muestras clínicas de seres humanos. Caso clínico: Se describe el caso de un paciente con inmunodeficiencia primaria y afectación pulmonar con evolución tórpida. Presentó compromiso de ambos pulmones a pesar del tratamiento antibiótico y antifúngico instaurado. Durante su seguimiento, se realizaron múltiples biopsias pulmonares y se aisló A. kalrae en el cultivo de tejido pulmonar. Recibió tratamiento con posaconazol, con buena respuesta y remisión de las lesiones. Conclusión: Este es el primer caso reportado de infección pulmonar por A. kalrae en un paciente pediátrico con enfermedad granulomatosa crónica en Argentina.

Background: Arthrographis kalrae is a hyaline fungus that grows forming arthroconidia. It is an opportunistic pathogen that causes infections in immunocompromised as in immunocompetent people and has been rarely isolated from human clinical samples. Case report: We describe the case of a male child with primary immunodeficiency who initially presented unilateral pneumonia and progressed to bilateral involvement despite antibiotic, antifungal treatment. A. kalrae was diagnosed by pulmonary biopsy. He received posaconazole with resolution of disease. Conclusions: This is the first case of A. kalrae pulmonary infection in a pediatric patient with chronic granulomatous disease in Argentina.

[Pulmonary infection by Arthrographis kalrae in patient with chronic granulomatous disease]. / Infección pulmonar por Arthrographis kalrae en un paciente con enfermedad granulomatosa crónica.

BACKGROUND: Arthrographis kalrae is a hyaline fungus that grows forming arthroconidia. It is an opportunistic pathogen that causes infections in immunocompromised as in immunocompetent people and has been rarely isolated from human clinical samples. CASE REPORT: We describe the case of a male child with primary immunodeficiency who initially presented unilateral pneumonia and progressed to bilateral involvement despite antibiotic, antifungal treatment. A. kalrae was diagnosed by pulmonary biopsy. He received posaconazole with resolution of disease. CONCLUSIONS: This is the first case of A. kalrae pulmonary infection in a pediatric patient with chronic granulomatous disease in Argentina.

ANTECENDENTES: Arthrographis kalrae es un hongo hialino de crecimiento lento que, en su desarrollo, forma artroconidios. Es un patógeno oportunista que causa infecciones en personas inmunocomprometidas e inmunocompetentes, y ha sido aislado muy raramente en muestras clínicas de seres humanos. CASO CLÍNICO: Se describe el caso de un paciente con inmunodeficiencia primaria y afectación pulmonar con evolución tórpida. Presentó compromiso de ambos pulmones a pesar del tratamiento antibiótico y antifúngico instaurado. Durante su seguimiento, se realizaron múltiples biopsias pulmonares y se aisló A. kalrae en el cultivo de tejido pulmonar. Recibió tratamiento con posaconazol, con buena respuesta y remisión de las lesiones. CONCLUSIÓN: Este es el primer caso reportado de infección pulmonar por A. kalrae en un paciente pediátrico con enfermedad granulomatosa crónica en Argentina.

Mycobacterial disease in patients with chronic granulomatous disease: A retrospective analysis of 71 cases.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by inborn errors of the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex. From the first year of life onward, most affected patients display multiple, severe, and recurrent infections caused by bacteria and fungi. Mycobacterial infections have also been reported in some patients. OBJECTIVE: Our objective was to assess the effect of mycobacterial disease in patients with CGD. METHODS: We analyzed retrospectively the clinical features of mycobacterial disease in 71 patients with CGD. Tuberculosis and BCG disease were diagnosed on the basis of microbiological, pathological, and/or clinical criteria. RESULTS: Thirty-one (44%) patients had tuberculosis, and 53 (75%) presented with adverse effects of BCG vaccination; 13 (18%) had both tuberculosis and BCG infections. None of these patients displayed clinical disease caused by environmental mycobacteria, Mycobacterium leprae, or Mycobacterium ulcerans. Most patients (76%) also had other pyogenic and fungal infections, but 24% presented solely with mycobacterial disease. Most patients presented a single localized episode of mycobacterial disease (37%), but recurrence (18%), disseminated disease (27%), and even death (18%) were also observed. One common feature in these patients was an early age at presentation for BCG disease. Mycobacterial disease was the first clinical manifestation of CGD in 60% of these patients. CONCLUSION: Mycobacterial disease is relatively common in patients with CGD living in countries in which tuberculosis is endemic, BCG vaccine is mandatory, or both. Adverse reactions to BCG and severe forms of tuberculosis should lead to a suspicion of CGD. BCG vaccine is contraindicated in patients with CGD.

Long-term follow-up of STAT5B deficiency in three argentinian patients: clinical and immunological features.

UNLABELLED: The signal transducer and activator of transcription (STAT) family of proteins regulate gene transcription in response to a variety of cytokines. STAT5B, in particular, plays an important role in T cells, where it is a key mediator of interleukin-2 (IL-2) induced responses. STAT5B deficiency causes a rare autosomal recessive disorder reported in only a handful of individuals. There are currently ten published cases of STAT5B deficiency, four of which are Argentinians. AIM: This is a report of more than 10 years follow up of the clinical and immunological features of three Argentinian STAT5B deficient patients. CONCLUSION: More than a decade of follow-up demonstrates that STAT5B deficiency is associated with various clinical pathologies that cause significant morbidity. Early diagnosis is critical for the prevention and improvement of clinical outcomes for STAT5B deficient patients.

First report of the Hyper-IgM syndrome Registry of the Latin American Society for Immunodeficiencies: novel mutations, unique infections, and outcomes.

Hyper-IgM (HIGM) syndrome is a heterogeneous group of disorders characterized by normal or elevated serum IgM levels associated with absent or decreased IgG, IgA and IgE. Here we summarize data from the HIGM syndrome Registry of the Latin American Society for Immunodeficiencies (LASID). Of the 58 patients from 51 families reported to the registry with the clinical phenotype of HIGM syndrome, molecular defects were identified in 37 patients thus far. We retrospectively analyzed the clinical, immunological and molecular data from these 37 patients. CD40 ligand (CD40L) deficiency was found in 35 patients from 25 families and activation-induced cytidine deaminase (AID) deficiency in 2 unrelated patients. Five previously unreported mutations were identified in the CD40L gene (CD40LG). Respiratory tract infections, mainly pneumonia, were the most frequent clinical manifestation. Previously undescribed fungal and opportunistic infections were observed in CD40L-deficient patients but not in the two patients with AID deficiency. These include the first cases of pneumonia caused by Mycoplasma pneumoniae, Serratia marcescens or Aspergillus sp. and diarrhea caused by Microsporidium sp. or Isospora belli. Except for four CD40L-deficient patients who died from complications of presumptive central nervous system infections or sepsis, all patients reported in this study are alive. Four CD40L-deficient patients underwent successful bone marrow transplantation. This report characterizes the clinical and genetic spectrum of HIGM syndrome in Latin America and expands the understanding of the genotype and phenotype of this syndrome in tropical areas.

Comparative study of subcutaneous versus intravenous IgG replacement therapy in pediatric patients with primary immunodeficiency diseases: a multicenter study in Argentina.

PURPOSE: Several studies have shown that subcutaneous immunoglobulin (SCIG) infusions demonstrate similar efficacy to intravenous Ig (IVIG) in preventing infections in patients with primary immunodeficiency diseases (PID), and are safe and well tolerated in this population. This open, prospective/retrospective, multicenter study was designed to compare the effectiveness, safety and tolerability of a 16 % liquid human IgG preparation (Beriglobina P), administered SC, with previous IVIG treatment in PID pediatric patients in Argentina. METHODS: Fifteen subjects were enrolled in the study, and a total of 13 subjects (aged 6-18 years) completed the 36-week SCIG treatment period. All children had previously received IVIG treatment. The dose of SCIG equaled the previous IVIG dose and subjects received an average weekly dose of 139 mg/kg (range 105-181) during the SCIG period. RESULTS: Significantly higher serum IgG trough levels were recorded on SCIG treatment at 16, 24, and 36 weeks, when compared with previous IgG trough levels on steady-state IVIG treatment. The annualized infection rate was 1.4 infections/subject/year during the IVIG administration period compared with 0.4 infections/subject/year during the SCIG period. All subjects who completed the study chose to continue administering SCIG at home after the study had ended. CONCLUSIONS: These data confirm that self-administered SCIG therapy is a well-tolerated and effective alternative to IVIG therapy for children with PID.

Human natural killer cell maturation defect supports in vivo CD56(bright) to CD56(dim) lineage development.

Two populations of human natural killer (NK) cells can be identified in peripheral blood. The majority are CD3(-)CD56(dim) cells while the minority exhibits a CD3(-)CD56(bright) phenotype. In vitro evidence indicates that CD56(bright) cells are precursors of CD56(dim) cells, but in vivo evidence is lacking. Here, we studied NK cells from a patient that suffered from a melanoma and opportunistic fungal infection during childhood. The patient exhibited a stable phenotype characterized by a reduction in the frequency of peripheral blood CD3(-)CD56(dim) NK cells, accompanied by an overt increase in the frequency and absolute number of CD3(-)CD56(bright) cells. These NK cells exhibited similar expression of perforin, CD57 and CD158, the major activating receptors CD16, NKp46, NKG2D, DNAM-1, and 2B4, as well as the inhibitory receptor CD94/NKG2A, on both CD56(bright) and CD56(dim) NK cells as healthy controls. Also, both NK cell subpopulations produced IFN-γ upon stimulation with cytokines, and CD3(-)CD56(dim) NK cells degranulated in response to cytokines or K562 cells. However, upon stimulation with cytokines, a substantial fraction of CD56(dim) cells failed to up-regulate CD57 and CD158, showed a reduction in the percentage of CD16(+) cells, and CD56(bright) cells did not down-regulate CD62L, suggesting that CD56(dim) cells could not acquire a terminally differentiated phenotype and that CD56(bright) cells exhibit a maturation defect that might result in a potential altered migration pattern. These observations, support the notion that NK cells of this patient display a maturation/activation defect that precludes the generation of mature NK cells at a normal rate accompanied by CD56(dim) NK cells that cannot completely acquire a terminally differentiated phenotype. Thus, our results provide evidence that support the concept that in vivo CD56(bright) NK cells differentiate into CD56(dim) NK cells, and contribute to further understand human NK cell ontogeny.

A novel missense mutation in the SH2 domain of the STAT5B gene results in a transcriptionally inactive STAT5b associated with severe IGF-I deficiency, immune dysfunction, and lack of pulmonary disease.

CONTEXT: Signal transducer and activator of transcription 5b (STAT5b) deficiency, first reported in a patient who carried a p.Ala630Pro missense mutation in the Src homology 2 (SH2) domain, results in a rare clinical condition of GH insensitivity (GHI), IGF-I deficiency (IGFD), and severe immune dysregulation manifesting as progressive worsening of pulmonary function. PATIENT: The new patient presented with severe cutaneous eczema, episodic infections in the first years of life, and autoimmune thyroiditis. Immunological evaluation revealed T lymphopenia, but severe pulmonary symptoms were notably absent. She concomitantly exhibited pronounced growth failure, reaching an adult height of 124.7 cm [-5.90 SD score (SDS)]. Endocrine evaluations (normal provocative GH tests; low serum IGF-I, -3.7 SDS, and IGF-binding protein-3, -4.5 SDS) were consistent with GHI and IGFD. RESULTS: Analysis of the STAT5B gene revealed a novel homozygous missense mutation, p.Phe646Ser, located within the ßD' strand of the SH2 domain. Reconstitution studies demonstrated expression of the p.Phe646Ser variant was less robust than wild type but, in contrast to the previously described STAT5B p.Ala630Pro SH2 mutation, could be phosphorylated in response to GH and interferon-γ. The phosphorylated p.Phe646Ser, however, could not drive transcription. CONCLUSION: A novel STAT5B p.Phe646Ser mutation has been identified in a patient with clinical characteristics of STAT5b deficiency. Only the second STAT5B missense mutation identified, its lack of transcriptional activities despite GH-induced phosphorylation, confirms the crucial role of STAT5b for regulating the expression of IGF1 and provides insights into the importance of the SH2 ßD' strand for full STAT5b transcriptional activities. Whether the phosphorylated p.Phe646Ser variant retained functions that prevented pulmonary distress remains unresolved.

Molecular characterization of a novel splice site mutation within the CYBB gene leading to X-linked chronic granulomatous disease.

Chronic granulomatous disease (CGD) is a primary immunodeficiency that affects the oxidative mechanism of microbial killing of phagocytic cells. The defect is characterized by a lack or severely reduced superoxide anion (O2-) production by phagocytes. Seventy percent of CGD cases are X-linked (X-CGD) and they are caused by mutations in the gene encoding for gp91(phox), one of the two subunits of the flavocytochrome b558 of the NADPH oxidase. We identified an abnormal transcript arising from a novel splice site mutation within the gene encoding gp91(phox), which suggested that the mutation affected normal mRNA splicing. Thus, the effect of this mutation leads to the complete absence of the flavocytochrome b558 in neutrophil membranes, which caused the biochemical phenotype X91 degrees-CGD in this family. These molecular findings help to explain the early onset and severe phenotype in this X-CGD kindred.

Evaluación clínica e inmunológica de 90 pacientes con deficiencia selectiva de inmunoglobulina A / A clinical and immunological evaluation of 90 patients with selective IgA deficiency

Introducción.La deficiencia selectiva de IgA se comporta como una enfermedad heterogénea, (asintomática o sintomática con infecciones recurrentes respiratorias o gastrointestinales, enfermedades atópicas y autoinmunes), caracterizada por presentar IgA de 7mg/dl o menos en pacientes de 4 años de edad o mas. Entre 1990 y 1999 se registraron en nuestro servicio 176 inmunodeficiencias primarias; la inmunodeficiencia selectiva de IgA representó el 61 por ciento. Objetivo. Describir las distintas formas de presentación clínica de la deficiencia selectiva de IgA y buscar un patrón inmunológico que permita diferenciarlas. Población, material y métodos. Se evaluaron inmunológicamente 90 pacientes con diagnóstico de inmunodeficiencia selectiva de IgA. Se excluyeron 18 pacientes por falta de seguimiento

Evaluación clínica e inmunológica de 90 pacientes con deficiencia selectiva de inmunoglobulina A / A clinical and immunological evaluation of 90 patients with selective IgA deficiency

Introducción.La deficiencia selectiva de IgA se comporta como una enfermedad heterogénea, (asintomática o sintomática con infecciones recurrentes respiratorias o gastrointestinales, enfermedades atópicas y autoinmunes), caracterizada por presentar IgA de 7mg/dl o menos en pacientes de 4 años de edad o mas. Entre 1990 y 1999 se registraron en nuestro servicio 176 inmunodeficiencias primarias; la inmunodeficiencia selectiva de IgA representó el 61 por ciento. Objetivo. Describir las distintas formas de presentación clínica de la deficiencia selectiva de IgA y buscar un patrón inmunológico que permita diferenciarlas. Población, material y métodos. Se evaluaron inmunológicamente 90 pacientes con diagnóstico de inmunodeficiencia selectiva de IgA. Se excluyeron 18 pacientes por falta de seguimiento