Patricia María O`´ Farrill Romanillos

Background: Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by defective antibody production and impaired differentiation of B cells. B cell proliferation is an essential step for antibody synthesis. Depending on the nature of the stimulus, their response may be either T-cell-dependent or T-cell-independent. Methods: We studied 23 CVID patients and 14 healthy donors (HD). The patients were categorized based on their percentage of memory B cells. In addition to standard immunophenotyping of circulating human B and T cell subsets, an in vitro CFSE dilution assay was used to assess the proliferative capacity of B cells and to compare the activation of the T cell-dependent and T cell-independent response among the patients. Results: Patients with a reduction in memory B cells exhibited an increase in follicular T cells (Tfh) and showed low proliferation in response to PKW, CpG, and SAC stimuli (Condition II) (p= 0.0073). In contrast, patients with a normal percentage of memory B cells showed a high expression of IL-21R and low proliferation in response to CPG (Condition III); IL-21, CD40L, and anti-IgM (Condition IV) stimuli (p= 0.0163 and p = 0.0475, respectively). Conclusion: Defective proliferation in patients depends on the type of stimulus used and the phenotypic characteristics of the patients. Further studies are necessary to understand the disease mechanisms, which may guide us toward identifying genetic defects associated with CVID.

Objective: Estimate the prevalence of dermatological manifestations in Mexican patients with common variable immunodeficiency. Methods: Cross-sectional and retrospective study, based on the analysis of records of patients with a diagnosis of common variable immunodeficiency, treated at the Siglo XXI National Medical Center (Mexican Social Security Institute), according to the criteria of the European Society of Immunodeficiencies (ESID). and of which only 3 had a genetic diagnosis with the following mutations: IRF2, CTLA4 and PIK-3, belonging to the Immunodeficiency Clinic of the National Medical Center Siglo XXI (IMSS), to evaluate dermatological manifestations, review of laboratory tests: IgA, IgM, IgG and type of replacement therapy with Immunoglobulin. The statistical analysis was carried out with the SPSS program; Descriptive statistics were used to analyze the data, according to the type of variable to be analyzed. Results: 36 patients were included, of which 55.5% were women; with median age 34 years (18-94). The prevalence of dermatological manifestations was 70% (n = 25). 30.5% had a history of infectious dermatosis and 39.5% had a history of non-infectious dermatosis. The most common dermatosis was irritant contact dermatitis in 13.8% of patients. All received replacement therapy with human immunoglobulin, 33.3% intravenously and the rest subcutaneously. Conclusions: Common variable immunodeficiency is an inborn error of immunity, with different clinical manifestations in various organs and systems (the skin is one of these). Dermatological manifestations are not usually described in patients with common variable immunodeficiency; However, it is important to identify them due to their relationship with certain complications (increased risk of superinfection), due to skin disruption and biological therapies. Keywords: Antibody immunodeficiency; Common variable immunodeficiency; skin diseases.

Background: G6PC3 deficiency is a rare genetic disorder that causes syndromic congenital neutropenia. It is driven by the intracellular accumulation of a metabolite named 1,5-anhydroglucitol-6-phosphate (1,5-AG6P) that inhibits glycolysis. Patients display heterogeneous extra-hematological manifestations, contributing to delayed diagnosis. Objective: The G6PC3 c.210delC variant has been identified in patients of Mexican origin. We set out to study the origin and functional consequence of this mutation. Furthermore, we sought to characterize the clinical phenotypes caused by it. Methods: Using whole-genome sequencing data, we conducted haplotype analysis to estimate the age of this allele and traced its ancestral origin. We examined how this mutation affected G6PC3 protein expression and performed extracellular flux assays on patient-derived cells to characterize how this mutation impacts glycolysis. Finally, we compared the clinical presentations of patients with the c.210delC mutation relative to other G6PC3 deficient patients published to date. Results: Based on the length of haplotypes shared amongst ten carriers of the G6PC3 c.210delC mutation, we estimated that this variant originated in a common ancestor of indigenous American origin. The mutation causes a frameshift that introduces a premature stop codon, leading to a complete loss of G6PC3 protein expression. When treated with 1,5-anhydroglucitol (1,5-AG), the precursor to 1,5-AG6P, patient-derived cells exhibited markedly reduced engagement of glycolysis. Clinically, c.210delC carriers display all the clinical features of syndromic severe congenital neutropenia type 4 observed in prior reports of G6PC3 deficiency. Conclusion: The G6PC3 c.210delC is a loss-of-function mutation that arose from a founder effect in the indigenous Mexican population. These findings may facilitate the diagnosis of additional patients in this geographical area. Moreover, the in vitro 1,5-AG-dependent functional assay used in our study could be employed to assess the pathogenicity of additional G6PC3 variants.

Hasta el 25% de los pacientes con inmunodeficiencia común variable (IDCV) debutan con autoinmunidad, la cual guarda relación con la clasificación de Freiburg, que se basa en la citometría de flujo. determinar la frecuencia y tipo de enfermedades autoinmunes y su asociación con la clasificación de Freiburg en adultos con IDCV. se realizó un estudio transversal, analítico y observacional con 33 pacientes pertenecientes a la Clínica de Inmunodeficiencias Primarias de un hospital de tercer nivel con diagnóstico de IDCV. Se dividieron en tres fenotipos según la clasificación de Freiburg. de los 33 pacientes estudiados, el 66.6% presentó enfermedades autoinmunes, de ellos 19 (86.3%) tuvieron citopenias. El 42.1% se clasificó en el grupo Ia de Freiburg, el 36.8% en el grupo Ib y el 21% en el fenotipo II. En el 36.6% de los pacientes las citopenias autoinmunes fueron la primera manifestación de IDCV, y hasta el 70% de ellos pertenecen al fenotipo Ia de Freiburg (p = 0.086). Los pacientes con citopenias autoinmunes tuvieron un menor porcentaje de células B de memoria con cambio de isotipo (p = 0.018), sin mayor porcentaje de células B CD21^low (p = 0.226). la clasificación por fenotipos en IDCV permite identificar el perfil del paciente y el tipo de manifestaciones asociadas, lo que es útil para buscar de manera intencionada complicaciones no infecciosas propias de la enfermedad.

Las consecuencias de la infección por SARS-CoV-2 en pacientes con inmunodeficiencias primarias (ahora llamadas errores innatos de la inmunidad) o secundarias aún es un tema de debate. Existe en la literatura pocos reportes de pacientes con síndrome de Good e infección por SARS-CoV-2 con desenlaces variables. paciente masculino de 51 años de edad con diagnóstico de síndrome de Good en tratamiento con inmunoglobulina humana intravenosa (IGIV) a dosis de sustitución con aplicación cada 21 días y profilaxis para P. jirovecii con trimetoprim/sulfametoxazol por linfopenia profunda a expensas de linfocitos T CD4+, que presentó infección por SARS-CoV-2 (RT-PCR+) leve, que progresó a neumonía con falla respiratoria aguda y que requirió manejo avanzado de la vía aérea e ingreso a UCI con desenlace fatal por sobreinfección luego de 14 días hospitalizado. se ha documentado en pacientes con inmunodeficiencias humorales mejor pronóstico por desarrollar síndrome de liberación de citocinas de menor intensidad. La alteración en la inmunidad celular, sobre todo linfopenia a expensas de linfocitos T CD4+, puede estar asociado con un peor pronóstico al verse comprometida la respuesta contra virus, así como la alta susceptibilidad a sobreinfección por agentes oportunistas como P. aeruginosa y Mucor sp. Por esta razón, debemos mantener una estrecha vigilancia en los pacientes con errores innatos de la inmunidad con defectos celulares como es el caso de los pacientes con síndrome de Good que presenten COVID-19.

El síndrome polen-alimento (SPA) se caracteriza por la sensibilización alérgica a proteínas de pólenes de pastos, malezas y árboles, que producen una reacción de hipersensibilidad de tipo I, asociada a la ingesta de alimentos derivados de plantas, usualmente en forma cruda. Las familias de proteínas que más frecuentemente están asociadas son las profilinas, las PR-10 y las ns LTP; sin embargo, se ha documentado otras, como las taumatinas, isoflavonas reductasas y las B1,2 gluconasas. El síndrome prototipo es el abedul-frutas-vegetales, y de ellos el más común es el abedul-manzana, debido a que más de 70 % de los pacientes sensibilizados al abedul presentan síntomas asociados a la ingesta de alimentos derivados de plantas. Los síntomas están restringidos a la cavidad oral; sin embargo, algunos pacientes pueden presentar síntomas sistémicos, incluso anafilaxia, por lo que es importante identificar el tipo de proteína implicada, ya que de eso depende el tipo de reacción que puede presentar el paciente. Pese a todo, se considera una entidad que puede estar subdiagnosticada debido a su valoración y tratamiento complejos, debido a que el procedimiento en la mayor parte de los casos es dieta de eliminación, ya que aún no está disponible el tratamiento con inmunoterapia. El objetivo de esta revisión es describir la fisiopatología, así como los síndromes polen-alimento más comunes.

Background: Chronic urticaria (CU) affects 5 % of the general population and it is associated with thyroid disease in up to 54 % of patients. There is scarce information on the activity of urticaria in patients with and without alterations in the thyroid function.Objective: To compare the activity rate of urticaria using the UAS7 (Urticaria Activity Score 7) in patients with and without hypothyroidism.Methods: A descriptive, cross-sectional, and comparative study of patients with CSU (chronic spontaneous urticaria) who were older than 18 years of age, who were classified into two groups based on their thyroid function: hypothyroid and euthyroid patients. UAS7 was applied to all of them. Results: We analyzed 60 patients with CSU; 30 of them were euthyroid and 30 were hypothyroid. The female sex was predominant (76 %) and the average age was 49.1 years old. The activity in 40 % was moderate, in 25 % was severe, and it was mild in 23 %; only 12 % of them were controlled. In the group with hypothyroidism, the median TSH (Thyroid Stimulating Hormone) was of 6.8 μUI/mL. No statistically significant differences were found in matters of age, body mass index, comorbidities, or in the UAS7.Conclusions: We did not find a statistically significant difference in the Urticaria Activity Index between both groups. Identifying the influencing factors shall improve the quality of life of patients.

Humoral immune deficiencies (HID) comprise a group of diseases characterized by the impossibility to develop an effective immune response mediated by immunoglobulins (Ig). Patients with HID have infections caused by capped extracellular bacteria, mainly in the respiratory and/or gastrointestinal tract, and a higher predisposition to suffer from autoimmune diseases and cancer. Some of them are caused by well-defined genetic defects, while the cause of others is unknown. The clinical manifestations of some HID may be late and the diagnosis is supported by laboratory tests, such as serum level of the Ig, determination of lymphocyte populations, and functional studies. Gamma-globulin replacement therapy significantly decreases serious infections. In order to achieve an early diagnosis, it is necessary to maintain a high index of suspicion and evaluate the clinical and laboratory manifestations that suggest HID. Mass sequencing technologies have favored the description of mutations in various genes that lead to a clinical HID phenotype; which paves the way to a better understanding of immune pathologies in HID.