Case report on activated PI3K-delta syndrome.

BACKGROUND: Activated phosphoinositide 3-kinase delta syndrome (APDS) [OMIM 615513] is an inborn error of immunity with autosomal dominant inheritance caused by a pathogenic variant in the PIK3CD gene. The prevalence ratio of APDS is < 1: 1,000,000 newborns. The main clinical features of APDS are sinopulmonary infections, benign lymphoproliferation, autoinflammatory disease, and a major risk of lymphoid neoplasms. CLINICAL CASE: A 17-year-old female with a history of pneumonia at 9 months of age subsequently developed recurrent respiratory tract infections, bronchiectasis, perforated otitis media, unilateral tonsillar lymphoid hyperplasia, pansinusitis, recurrent oral candidiasis, and chronic rhinitis. Laboratory studies reported persistent leukopenia and lymphopenia, low CD4 lymphocyte subpopulation, and persistently elevated immunoglobulin M immunoglobulin studies with values up to 692 mg/dL. An inborn error of immunity next-generation sequencing and multiplex ligation-dependent probe amplification analysis detected a heterozygous pathogenic variant in the PIK3CD gene, compatible with APDS. Treatment with monthly injectable gamma globulin and prophylactic antibiotics was started, allowing better control of the infectious processes. CONCLUSION: This is the second case of APDS reported in Mexico in the literature. It is important to be aware of this condition to make a timely diagnosis, which requires a high clinical suspicion and immunological and genetic studies to provide adequate treatment and prevent complications.

INTRODUCCIÓN: El síndrome de la Fosfoinositida 3-cinasa delta activado (Activated Phosphoinositide 3-kinase δ síndrome, APDS) [OMIM 615513] es un error innato de la inmunidad con patrón de herencia autosómica dominante causada por una variante patogénica heterocigota del gen PIK3CD. Su prevalencia es < 1: 1,000,000 nacidos vivos. Las principales manifestaciones clínicas son infecciones sinopulmonares, linfoproliferación benigna, autoinmunidad y aumento del riesgo de malignización linfoide. CASO CLÍNICO: Femenino de 17 años de vida con antecedentes de neumonía a los 9 meses de edad, posteriormente infecciones de vías respiratorias recurrentes, bronquiectasias, otitis media perforada, hiperplasia linfoide de amigdala unilateral, pansinusitis, candidiasis oral recurrente y rinitis crónica. Los estudios de laboratorio reportaron leuco linfopenia persistente, subpoblación linfocitaria con CD4 baja y estudios de inmunoglobulinas con IgM persistentemente elevada con valor de hasta 692 mg/dl. Se realizó estudio molecular de secuenciación de siguiente generación (NGS por sus siglas en inglés Next-Generation Sequencing) y amplificación de sondas dependientes de ligandos múltiples (MLPA por sus siglas en inglés Multiplex Ligation-dependent Probe Amplification) dirigido a errores innatos de la inmunidad que detectó una variante patogénica en estado heterocigoto en el gen PIK3CD, compatible con APDS. Se inició tratamiento con gammaglobulina intravenosa mensual y antibiótico profiláctico, permitiendo mejor control de los procesos infecciosos. CONCLUSIONES: Este es el segundo caso reportado en la literatura de APDS en México, por lo que es importante su conocimiento para poder realizar un diagnóstico oportuno, para el cual se requiere una alta sospecha clínica, además de estudios inmunológicos y genéticos, con la finalidad de otorgar el tratamiento adecuado y prevenir complicaciones.

Childhood-onset systemic lupus erythematosus associated with inborn errors of immunity: One or several conditions? / Lupus eritematoso sistémico pediátrico asociado a un error de la inmunidad innata: ¿una enfermedad o varias?

Childhood-onset systemic lupus erythematosus (cSLE) is a multisystem disease; its severity depends on the organs involved. Monogenic diseases have been described as predisposing to the onset of cSLE. Analytical and immunological tests are used for diagnostic confirmation. The main goal of treatment is remission and flare prevention. Here we describe the clinical case of a patient with prolonged febrile syndrome, arthralgias, and anemia, positive analytical tests for antinuclear antibodies and anti-DNA antibodies and low values of complement C3, C4, and C1q; so the patient was diagnosed with cSLE associated with C1q deficiency. Patients with C1q deficiency present with early onset of disease and significant target organ damage with nephritis. An early diagnosis of cSLE is important to ensure an early and appropriate treatment. Treatment may be personalized depending on the underlying defect that generates the subtype of lupus.

El lupus eritematoso sistémico pediátrico (LESp) es una enfermedad multisistémica, cuya gravedad depende de los órganos afectados. Se han descrito enfermedades monogénicas que predisponen a la aparición de LESp. Para la confirmación diagnóstica, se realizan pruebas analíticas e inmunológicas. El objetivo principal del tratamiento es la remisión de la enfermedad y la prevención de brotes. Se presenta un caso clínico de una paciente con síndrome febril prolongado, artralgias y anemia, con pruebas analíticas positivas para ANA, anti-ADN y valores bajos de complemento C3, C4 y C1q, por lo que se realizó diagnóstico de LESp asociado a deficiencia de C1q. Los pacientes con deficiencia de C1q presentan inicio temprano y daño importante a órganos blanco con nefritis. Realizar un diagnóstico oportuno de LESp es importante para garantizar un tratamiento temprano y adecuado. El tratamiento se podría individualizar dependiendo del defecto subyacente que genere el subtipo de lupus.

Schimke immuno-osseous dysplasia. A case report in Colombia.

Background: Schimke immune-osseous dysplasia (SIOD) is an ultra-rare multisystemic, monogenic, and autosomal recessive inherited disease caused by biallelic mutations in the SMARCAL1 gene. Approximately 100 cases have been reported worldwide. The disease is characterized by skeletal, renal, and immunological abnormalities. Case description: This is a 6-year-old female patient who debuted with nephrotic syndrome at five years of age, with a switch to corticosteroid resistance and poor response to immunosuppressive treatment received. The patient was admitted and referred to our institution due to convulsive status. During her hospitalization, thrombosis was found in the left renal vein, and a renal biopsy report of Collapsing Focal and Segmental Glomerulosclerosis (FSGS) was obtained. The patient had multiple infections during hospitalization, with T lymphocyte lymphopenia and severe IgG hypogammaglobulinemia. Additionally, given dysmorphic facies, delayed weight-height development, and spondyloepiphyseal dysplasia, exome sequencing was performed, finding an homozygous pathogenic variant c.1933C > T p.Arg645Cys in SMARCAL1, compatible with the diagnosis of SIOD. Discussion: We present the case of a patient that exhibited a severe phenotype of the disease, with skeletal, renal, severe combined immunological compromise and cerebrovascular involvement during follow-up, and the available proposed mechanisms of the disease focused on the clinical manifestations of this patient. It is the first case of SIOD reported in Colombia and the first comprehensive characterization reported in the literature of a patient with homozygosity of the known variant c.1933C > T p.Arg645Cys. Conclusion: A severe phenotype of the disease with cerebrovascular involvement by homozygosity of the known variant c.1933C > T p.Arg645Cys in the SMARCAL1 gene can be expected.

Prospective evaluation of Streptococcus pneumoniae serum antibodies in patients with primary immunodeficiency on regular intravenous immunoglobulin treatment.

BACKGROUND: This is a prospective study that assessed pneumococcal antibody levels in PID patients under intravenous immunoglobulin (IVIG) treatment using different brands. METHODS: Twenty-one patients receiving regular IVIG every 28 days were invited to participate: 12 with common variable immunodeficiency, six with X-linked agammaglobulinaemia and three with hyper-IgM syndrome. One blood sample was collected from each patient just prior to IVIG administration at a three-month time interval during one year. A questionnaire was filled in with patient's demographic data and history of infections during the study period. Streptococcus pneumoniae antibodies against six serotypes (1, 5, 6B, 9V, 14 and 19F) were assessed by ELISA both in patients' serum (trough levels) and in IVIG samples. RESULTS: Median total IgG trough serum levels were 7.91g/L (range, 4.59-12.20). All patients had antibody levels above 0.35µg/mL to the six serotypes on all four measurements. However, only 28.6% of patients had pneumococcal antibodies for the six analysed serotypes above 1.3µg/mL on all four evaluations during the one-year period. No correlation was found between IgG trough levels and pneumococcal specific antibodies. Eighteen of the 21 patients (85.7%) had infections at some point during the 12-month follow-up, 62/64 (96.9%) clinically classified in respiratory tract infections, four of which were pneumonia. CONCLUSIONS: Pneumococcal antibodies are present in a high range of concentrations in sera from PID patients and also in IVIG preparations. Even maintaining a recommended IgG trough level, these patients can be susceptible to these bacteria and that may contribute to recurrent respiratory infections.