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.

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.