Cancer Prevalence in Children with Inborn Errors of Immunity: Report from a Single Institution.

BACKGROUND: Inborn Errors of Immunity (IEI) comprise several genetic anomalies that affect different components of the innate and adaptive responses, predisposing to infectious diseases, autoimmunity and malignancy. Different studies, mostly in adults, have reported a higher prevalence of cancer in IEI patients. However, in part due to the rarity of most of these IEI subtypes (classified in ten categories by the Primary Immunodeficiency Committee of the International Union of Immunological Societies), it is difficult to assess the risk in a large number of patients, especially during childhood. OBJECTIVE: To document the cancer prevalence in a pediatric cohort from a single referral institution, assessing their risk, together with the type of neoplasia within each IEI subgroup. METHOD: An extensive review of clinical records from 1989 to 2022 of IEI patients who at some point developed cancer before the age of sixteen. RESULTS: Of a total of 1642 patients with IEI diagnosis, 34 developed cancer before 16 years of age, showing a prevalence (2.1%) significantly higher than that of the general age matched population (0.22). Hematologic neoplasms (mostly lymphomas) were the most frequent malignancies. CONCLUSION: This study represents one of the few reports focused exclusively in pediatric IEI cases, describing not only the increased risk of developing malignancy compared with the age matched general population (a fact that must be taken into account by immunologists during follow-up) but also the association of the different neoplasms with particular IEI subtypes, thus disclosing the possible mechanisms involved.

Expanding spectrum, intrafamilial diversity, and therapeutic challenges from 15 patients with heterozygous CARD11-associated diseases: A single center experience.

CARD11-associated diseases are monogenic inborn errors of immunity involving immunodeficiency, predisposition to malignancy and immune dysregulation such as lymphoproliferation, inflammation, atopic and autoimmune manifestations. Defects in CARD11 can present as mutations that confer a complete or a partial loss of function (LOF) or contrarily, a gain of function (GOF) of the affected gene product. We report clinical characteristics, immunophenotypes and genotypes of 15 patients from our center presenting with CARD11-associated diseases. Index cases are pediatric patients followed in our immunology division who had access to next generation sequencing studies. Variant significance was defined by functional analysis in cultured cells transfected with a wild type and/or with mutated hCARD11 constructs. Cytoplasmic aggregation of CARD11 products was evaluated by immunofluorescence. Nine index patients with 9 unique heterozygous CARD11 variants were identified. At the time of the identification, 7 variants previously unreported required functional validation. Altogether, four variants showed a GOF effect as well a spontaneous aggregation in the cytoplasm, leading to B cell expansion with NF-κB and T cell anergy (BENTA) diagnosis. Additional four variants showing a LOF activity were considered as causative of CARD11-associated atopy with dominant interference of NF-kB signaling (CADINS). The remaining variant exhibited a neutral functional assay excluding its carrier from further analysis. Family segregation studies expanded to 15 individuals the number of patients presenting CARD11-associated disease. A thorough clinical, immunophenotypical, and therapeutic management evaluation was performed on these patients (5 BENTA and 10 CADINS). A remarkable variability of disease expression was clearly noted among BENTA as well as in CADINS patients, even within multiplex families. Identification of novel CARD11 variants required functional studies to validate their pathogenic activity. In our cohort BENTA phenotype exhibited a more severe and expanded clinical spectrum than previously reported, e.g., severe hematological and extra hematological autoimmunity and 3 fatal outcomes. The growing number of patients with dysmorphic facial features strengthen the inclusion of extra-immune characteristics as part of the CADINS spectrum. CARD11-associated diseases represent a challenging group of disorders from the diagnostic and therapeutic standpoint, especially BENTA cases that can undergo a more severe progression than previously described.

Dermatofitosis por Microsporum gypseum en un niño con inmunodeficiencia primaria / Microsporum gypseum dermatophytosis in a child with primary immunodeficiency

El Microsporum gypseum es un hongo geofílico que puede producir lesiones cutáneas inflamatorias en personas sanas. Se han descripto lesiones más extensas en pacientes inmunocomprometidos. Se presenta el caso de un paciente con dermatofitosis, con exámenes micológicos positivos para Candida sp, Epidermophytom floccosum y Trichophyton tonsurans, al que, ante la mala respuesta al tratamiento con griseofulvina e itraconazol a dosis habituales, se le realizó biopsia cutánea para cultivo que evidenció la presencia de M. gypseum. Debido a la extensión y a la mala respuesta al tratamiento, se realizó evaluación inmunológica y se diagnosticó un defecto en STAT1 con ganancia de función (STAT1-GOF). Los pacientes que tienen esta inmunodeficiencia primaria son susceptibles a las infecciones micóticas, especialmente por Candida, pero también, aunque en menor medida, a virus y bacterias. El paciente aquí presentado recibió tratamiento prolongado con antimicóticos imidazólicos sistémicos, con resolución de las lesiones.

Microsporum gypseum is a geophilic fungus that can cause inflammatory skin lesions in heathy people. More extensive lesions have been described in immunocompromised patients. We present a patient with extensive dermatophytosis, which mycological examination led the identification of Candida sp, Epidermophyton Floccosum and Trichophyton tonsurans and showed poor response to treatment with griseofulvina and itraconazol at usual doses. When skin biopsy was performed, it had positive culture for M. gypseum. Due to the extension and poor response to treatment, immunological assessment was performed and it showed a defect of STAT1 with gain of function (STAT 1-GOF). Patients with primary immunodeficiency are susceptible to fungal infections, especially Candida but also virus and bacteria, although to a lesser extent. The patient received long-term treatment with systemic imidazole antifungal recovering for the lesions.

[Microsporum gypseum dermatophytosis in a child with primary immunodeficiency]. / Dermatofitosis por Microsporum gypseum en un niño con inmunodeficiencia primaria.

Microsporum gypseum is a geophilic fungus that can cause inflammatory skin lesions in heathy people. More extensive lesions have been described in immunocompromised patients. We present a patient with extensive dermatophytosis, which mycological examination led the identification of Candida sp, Epidermophyton Floccosum and Trichophyton tonsurans and showed poor response to treatment with griseofulvina and itraconazol at usual doses. When skin biopsy was performed, it had positive culture for M. gypseum. Due to the extension and poor response to treatment, immunological assessment was performed and it showed a defect of STAT1 with gain of function (STAT 1-GOF). Patients with primary immunodeficiency are susceptible to fungal infections, especially Candida but also virus and bacteria, although to a lesser extent. The patient received long-term treatment with systemic imidazole antifungal recovering for the lesions.

El Microsporum gypseum es un hongo geofílico que puede producir lesiones cutáneas inflamatorias en personas sanas. Se han descripto lesiones más extensas en pacientes inmunocomprometidos. Se presenta el caso de un paciente con dermatofitosis, con exámenes micológicos positivos para Candida sp, Epidermophytom floccosum y Trichophyton tonsurans, al que, ante la mala respuesta al tratamiento con griseofulvina e itraconazol a dosis habituales, se le realizó biopsia cutánea para cultivo que evidenció la presencia de M. gypseum. Debido a la extensión y a la mala respuesta al tratamiento, se realizó evaluación inmunológica y se diagnosticó un defecto en STAT1 con ganancia de función (STAT1-GOF). Los pacientes que tienen esta inmunodeficiencia primaria son susceptibles a las infecciones micóticas, especialmente por Candida, pero también, aunque en menor medida, a virus y bacterias. El paciente aquí presentado recibió tratamiento prolongado con antimicóticos imidazólicos sistémicos, con resolución de las lesiones.

Pulmonary Alveolar Proteinosis and Multiple Infectious Diseases in a Child with Autosomal Recessive Complete IRF8 Deficiency.

BACKGROUND: Autosomal recessive (AR) complete IRF8 deficiency is a rare severe inborn error of immunity underlying an absence of blood myeloid mononuclear cells, intracerebral calcifications, and multiple infections. Only three unrelated patients have been reported. MATERIALS AND METHODS: We studied an Argentinian child with multiple infectious diseases and severe pulmonary alveolar proteinosis (PAP). We performed whole-exome sequencing (WES) and characterized his condition by genetic, immunological, and clinical means. RESULTS: The patient was born and lived in Argentina. He had a history of viral pulmonary diseases, disseminated disease due to bacillus Calmette-Guérin (BCG), PAP, and cerebral calcifications. He died at the age of 10 months from refractory PAP. WES identified two compound heterozygous variants in IRF8: c.55del and p.R111*. In an overexpression system, the p.R111* cDNA was loss-of-expression, whereas the c.55del cDNA yielded a protein with a slightly lower molecular weight than the wild-type protein. The mutagenesis of methionine residues downstream from c.55del revealed a re-initiation of translation. However, both variants were loss-of-function in a luciferase assay, suggesting that the patient had AR complete IRF8 deficiency. The patient had no blood monocytes or dendritic cells, associated with neutrophilia, and normal counts of NK and other lymphoid cell subsets. CONCLUSION: We describe the fourth patient with AR complete IRF8 deficiency. This diagnosis should be considered in children with PAP, which is probably due to the defective development or function of alveolar macrophages.

Identification of Germline Non-coding Deletions in XIAP Gene Causing XIAP Deficiency Reveals a Key Promoter Sequence.

PURPOSE: X-linked inhibitor of apoptosis protein (XIAP) deficiency, also known as the X-linked lymphoproliferative syndrome of type 2 (XLP-2), is a rare immunodeficiency characterized by recurrent hemophagocytic lymphohistiocytosis, splenomegaly, and inflammatory bowel disease. Variants in XIAP including missense, non-sense, frameshift, and deletions of coding exons have been reported to cause XIAP deficiency. We studied three young boys with immunodeficiency displaying XLP-2-like clinical features. No genetic variation in the coding exons of XIAP was identified by whole-exome sequencing (WES), although the patients exhibited a complete loss of XIAP expression. METHODS: Targeted next-generation sequencing (NGS) of the entire locus of XIAP was performed on DNA samples from the three patients. Molecular investigations were assessed by gene reporter expression assays in HEK cells and CRISPR-Cas9 genome editing in primary T cells. RESULTS: NGS of XIAP identified three distinct non-coding deletions in the patients that were predicted to be driven by repetitive DNA sequences. These deletions share a common region of 839 bp that encompassed the first non-coding exon of XIAP and contained regulatory elements and marks specific of an active promoter. Moreover, we showed that among the 839 bp, the exon was transcriptionally active. Finally, deletion of the exon by CRISPR-Cas9 in primary cells reduced XIAP protein expression. CONCLUSIONS: These results identify a key promoter sequence contained in the first non-coding exon of XIAP. Importantly, this study highlights that sequencing of the non-coding exons that are not currently captured by WES should be considered in the genetic diagnosis when no variation is found in coding exons.

Inherited human Apollo deficiency causes severe bone marrow failure and developmental defects.

Inherited bone marrow failure syndromes (IBMFSs) are a group of disorders typified by impaired production of 1 or several blood cell types. The telomere biology disorders dyskeratosis congenita (DC) and its severe variant, Høyeraal-Hreidarsson (HH) syndrome, are rare IBMFSs characterized by bone marrow failure, developmental defects, and various premature aging complications associated with critically short telomeres. We identified biallelic variants in the gene encoding the 5'-to-3' DNA exonuclease Apollo/SNM1B in 3 unrelated patients presenting with a DC/HH phenotype consisting of early-onset hypocellular bone marrow failure, B and NK lymphopenia, developmental anomalies, microcephaly, and/or intrauterine growth retardation. All 3 patients carry a homozygous or compound heterozygous (in combination with a null allele) missense variant affecting the same residue L142 (L142F or L142S) located in the catalytic domain of Apollo. Apollo-deficient cells from patients exhibited spontaneous chromosome instability and impaired DNA repair that was complemented by CRISPR/Cas9-mediated gene correction. Furthermore, patients' cells showed signs of telomere fragility that were not associated with global reduction of telomere length. Unlike patients' cells, human Apollo KO HT1080 cell lines showed strong telomere dysfunction accompanied by excessive telomere shortening, suggesting that the L142S and L142F Apollo variants are hypomorphic. Collectively, these findings define human Apollo as a genome caretaker and identify biallelic Apollo variants as a genetic cause of a hitherto unrecognized severe IBMFS that combines clinical hallmarks of DC/HH with normal telomere length.

Correction to: A Nonsense N -Terminus NFKB2 Mutation Leading to Haploinsufficiency in a Patient with a Predominantly Antibody Deficiency.

Due to typesetting mistake, the caption of Figure 2 was mistakenly replaced with the caption of Figure 3.

A Nonsense N -Terminus NFKB2 Mutation Leading to Haploinsufficiency in a Patient with a Predominantly Antibody Deficiency.

The noncanonical NF-κB pathway is implicated in diverse biological and immunological processes. Monoallelic C-terminus loss-of-function and gain-of-function mutations of NFKB2 have been recently identified as a cause of immunodeficiency manifesting with common variable immunodeficiency (CVID) or combined immunodeficiency (CID) phenotypes. Herein we report a family carrying a heterozygous nonsense mutation in NFKB2 (c.809G > A, p.W270*). This variant is associated with increased mRNA decay and no mutant NFKB2 protein expression, leading to NFKB2 haploinsufficiency. Our findings demonstrate that bona fide NFKB2 haploinsufficiency, likely caused by mutant mRNA decay and protein instability leading to the transcription and expression of only the wild-type allele, is associated with clinical immunodeficiency, although with incomplete clinical penetrance. Abnormal B cell development, hypogammaglobulinemia, poor antibody response, and abnormal noncanonical (but normal canonical) NF-κB pathway signaling are the immunologic hallmarks of this disease. This adds a third allelic variant to the pathophysiology of NFKB2-mediated immunodeficiency disorders.

Inherited CARD9 Deficiency in a Patient with Both Exophiala spinifera and Aspergillus nomius Severe Infections.

PURPOSE: Caspase-associated recruitment domain-9 (CARD9) deficiency is an inborn error of immunity that typically predisposes otherwise healthy patients to single fungal infections and the occurrence of multiple invasive fungal infections is rare. It has been described as the first known condition that predisposes to extrapulmonary Aspergillus infection with preserved lungs. We present a patient that expands the clinical variability of CARD9 deficiency. MATERIALS AND METHODS: Genetic analysis was performed by Sanger sequencing. Neutrophils and mononuclear phagocyte response to fungal stimulation were evaluated through luminol-enhanced chemiluminescence and whole blood production of the proinflammatory mediator interleukin (IL)-6, respectively. RESULTS: We report a 56-year-old Argentinean woman, whose invasive Exophiala spinifera infection at the age of 32 years was unexplained and reported in year 2004. At the age of 49 years, she presented with chronic pulmonary disease due to Aspergillus nomius. After partial improvement following treatment with caspofungin and posaconazole, right pulmonary bilobectomy was performed. Despite administration of multiple courses of antifungals, sustained clinical remission could not be achieved. We recently found that the patient's blood showed an impaired production of IL-6 when stimulated with zymosan. We also found that she is homozygous for a previously reported CARD9 loss-of-function mutation (Q289*). CONCLUSIONS: This is the first report of a patient with inherited CARD9 deficiency and chronic invasive pulmonary aspergillosis (IPA) due to A. nomius. Inherited CARD9 deficiency should be considered in otherwise healthy children and adults with one or more invasive fungal diseases.

Latin American consensus on the supportive management of patients with severe combined immunodeficiency.

Severe combined immunodeficiency (SCID) represents the most lethal form of primary immunodeficiency, with mortality rates of greater than 90% within the first year of life without treatment. Hematopoietic stem cell transplantation and gene therapy are the only curative treatments available, and the best-known prognostic factors for success are age at diagnosis, age at hematopoietic stem cell transplantation, and the comorbidities that develop in between. There are no evidence-based guidelines for standardized clinical care for patients with SCID during the time between diagnosis and definitive treatment, and we aim to generate a consensus management strategy on the supportive care of patients with SCID. First, we gathered available information about SCID diagnostic and therapeutic guidelines, then we developed a document including diagnostic and therapeutic interventions, and finally we submitted the interventions for expert consensus through a modified Delphi technique. Interventions are grouped in 10 topic domains, including 123 "agreed" and 38 "nonagreed" statements. This document intends to standardize supportive clinical care of patients with SCID from diagnosis to definitive treatment, reduce disease burden, and ultimately improve prognosis, particularly in countries where newborn screening for SCID is not universally available and delayed diagnosis is the rule. Our work intends to provide a tool not only for immunologists but also for primary care physicians and other specialists involved in the care of patients with SCID.

Diagnóstico de enfermedad granulomatosa crónica (EGC): perspectiva desde la resolución de un caso clínico / Diagnosis of chronic granulomatous disease (CGD): perspective from the resolution of a clinical case

La EGC es una patología de baja prevalencia incluida en el grupo de los defectos congénitos de los fagocitos. Existen dos formas de transmisión genética: ligada a X, la más frecuente y grave, y autosómica recesiva. Se debe a mutaciones de los genes que codifican para las proteínas que constituyen el complejo NADP oxidasa lo que induce incapacidad en fagocitos para realizar el estallido respiratorio. El diagnóstico se fundamenta en el fenotipo clínico y de laboratorio; la prueba de dihidrorodamina (DHR) con estímulo de PMA por citometría de flujo es el método diagnóstico de elección. El diagnóstico definitivo es la identificación de la mutación genética por secuenciación del ADN. La terapéutica curativa de esta patología es el trasplante de células madres hematopoyéticas (TCHP). (AU)

CGD is a low prevalence pathology included in the group of congenital phagocyte defects. There are two forms of genetic transmission: the X-linked, the most frequent and severe, and autosomal recessive. It is due to a mutation of the genes coding for proteins that constitute the NADP oxidase complex, which induces inability of phagocytes to perform respiratory burst. The initial diagnosis is based on the clinical and laboratory phenotype; the dihydrorhodamine (DHR) test with PMA stimulation by flow cytometry is a diagnostic method of choice. The demonstration of the genetic mutation by DNA sequencing is the definitive diagnosis. The haemopoietic stem-cell transplantation (HSCT) is the curative therapy of this pathology. (AU)

Incomplete penetrance for isolated congenital asplenia in humans with mutations in translated and untranslated RPSA exons.

Isolated congenital asplenia (ICA) is the only known human developmental defect exclusively affecting a lymphoid organ. In 2013, we showed that private deleterious mutations in the protein-coding region of RPSA, encoding ribosomal protein SA, caused ICA by haploinsufficiency with complete penetrance. We reported seven heterozygous protein-coding mutations in 8 of the 23 kindreds studied, including 6 of the 8 multiplex kindreds. We have since enrolled 33 new kindreds, 5 of which are multiplex. We describe here 11 new heterozygous ICA-causing RPSA protein-coding mutations, and the first two mutations in the 5'-UTR of this gene, which disrupt mRNA splicing. Overall, 40 of the 73 ICA patients (55%) and 23 of the 56 kindreds (41%) carry mutations located in translated or untranslated exons of RPSA. Eleven of the 43 kindreds affected by sporadic disease (26%) carry RPSA mutations, whereas 12 of the 13 multiplex kindreds (92%) carry RPSA mutations. We also report that 6 of 18 (33%) protein-coding mutations and the two (100%) 5'-UTR mutations display incomplete penetrance. Three mutations were identified in two independent kindreds, due to a hotspot or a founder effect. Finally, RPSA ICA-causing mutations were demonstrated to be de novo in 7 of the 23 probands. Mutations in RPSA exons can affect the translated or untranslated regions and can underlie ICA with complete or incomplete penetrance.

Inherited p40phox deficiency differs from classic chronic granulomatous disease.

Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40phox-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients' neutrophils, whereas PMA-induced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD.

[Late diagnosis of WHIM sydrome]. / Diagnóstico tardío de síndrome WHIM.

WHIM syndrome is a primary autosomal dominant immuno deficiency due to CXCR4 mutations characterized by mucocutaneous warts, hypogammaglobulinemia, recurrent bacterial infections and myelokathesis. Treatment consists in prophylactic antibiotics, immunoglobulin replacement and granulocyte or granulocyte/monocyte colony stimulating factors. We present the case of a 21 year old woman who showed leukopenia at 10 months of age and one year later multiple infections with hypogammaglobulinemia requiring intravenous immunoglobulin. During follow up she developed chronic neutropenia. A bone marrow aspiration showed increased myeloid series with predominance of immature elements. On the basis of infections, low levels of IgG, IgA, IgM and lymphopenia with absent memory B cells, a diagnosis of common variable immunodeficiency was made. She started intravenous immunoglobulin replacement and prophylactic antibiotics. At age 20, small warts in hands that progressed to forearms, knees, abdomen and face were recorded. CXCR4 gene sequencing was done detecting a heterozygous p.Arg334STOP mutation, confirming WHIM syndrome. This disease is infrequent and difficult to diagnose.

Diagnóstico tardío de síndrome WHIM / Late diagnosis of WHIM sydrome

El síndrome WHIM es una inmunodeficiencia primaria de herencia autosómica dominante, debida a mutaciones en el gen CXCR4, que se caracteriza por verrugas cutáneo-mucosas, hipogammaglobulinemia, infecciones bacterianas recurrentes y mielocatesis. El tratamiento se basa en el uso de antibióticos profilácticos, gammaglobulina en dosis sustitutiva y factores estimulantes de colonias de granulocitos o de granulocitos y macrófagos, en forma crónica. Presentamos el caso de una mujer de 21 años que comenzó a los 10 meses de edad con leucopenia y al siguiente año múltiples infecciones con hipogammaglobulinemia requiriendo gammaglobulina endovenosa durante los episodios. Evolucionó con neutropenia crónica. Una punción aspiración de médula ósea mostró la serie mieloide aumentada con ligero predominio de elementos inmaduros. El cuadro fue interpretado como inmunodeficiencia común variable debido a la asociación de múltiples cuadros infecciosos, niveles disminuidos de IgG, IgM e IgA y linfopenia con disminución de linfocitos B de memoria, por lo que comenzó tratamiento sustitutivo con gammaglobulina endovenosa más antibióticos profilácticos. A los 20 años se registraron pequeñas verrugas en manos que progresaron hacia antebrazos, abdomen, cara y rodillas. Se realizaron estudios moleculares para la búsqueda de mutaciones en el gen CXCR4 donde se detectó la mutación p.Arg334STOP en estado heterocigota confirmando el diagnóstico de síndrome WHIM, que es una inmunodeficiencia infrecuente y de difícil diagnóstico.

WHIM syndrome is a primary autosomal dominant immuno deficiency due to CXCR4 mutations characterized by mucocutaneous warts, hypogammaglobulinemia, recurrent bacterial infections and myelokathesis. Treatment consists in prophylactic antibiotics, immunoglobulin replacement and granulocyte or granulocyte/monocyte colony stimulating factors. We present the case of a 21 year old woman who showed leukopenia at 10 months of age and one year later multiple infections with hypogammaglobulinemia requiring intravenous immunoglobulin. During follow up she developed chronic neutropenia. A bone marrow aspiration showed increased myeloid series with predominance of immature elements. On the basis of infections, low levels of IgG, IgA, IgM and lymphopenia with absent memory B cells, a diagnosis of common variable immunodeficiency was made. She started intravenous immunoglobulin replacement and prophylactic antibiotics. At age 20, small warts in hands that progressed to forearms, knees, abdomen and face were recorded. CXCR4 gene sequencing was done detecting a heterozygous p.Arg334STOP mutation, confirming WHIM syndrome. This disease is infrequent and difficult to diagnose.