Skewed Invariant Natural Killer T (iNKT) Cells, Impaired iNKT:B Cell Help and Decreased SAP Expression in Blood Lymphocytes from Patients with Common Variable Immunodeficiency.

Common variable immunodeficiency (CVID) is a syndrome with predominantly defective B cell function. However, abnormalities in the number and function of other lymphocyte subpopulations in peripheral blood (PB) have been described in most patients. We have analysed the distribution of iNKT cell subpopulations in the PB of CVID patients and the ability of these cells to provide in vitro cognate B cell help. The total of iNKT cells was reduced in the PB of CVID patients, especially CD4+, CD4-/CD8- and CCR5+/CXCR3+. These findings were associated with an enrichment of memory-like and a tendency towards a reduction in TNF-α-expressing effector iNKT cells in the peripheral blood mononuclear cells (PBMC) of CVID patients. Moreover, an accumulation of follicular helper iNKT cells in the PB of CVID patients was demonstrated. CVID αGalCer-pulsed iNKT cells are not able to induce autologous B cell proliferation although they do induce proliferation to healthy donor B cells. Interestingly, autologous and heterologous co-cultures did not differ in the amount of immunoglobulin secreted by B cells in vitro. Finally, reduced intracellular SAP expression in iNKT cells and other lymphocytes in the blood from CVID patients was observed. These results provide further insights into the immunological mechanisms underlying the iNKT cell defects and the potential targets to improve B cell help in CVID.

[A phenotypic description of 26 patients with Ritscher-Schinzel syndrome (cranio-cerebello-cardiac dysplasia or 3C syndrome)]. / Descripcion fenotipica de 26 pacientes con sindrome de Ritscher-Schinzel (displasia craneo-cerebelo-cardiaca o sindrome 3C).

INTRODUCTION: Ritscher-Schinzel syndrome (also known as cranio-cerebello-cardiac dysplasia or 3C syndrome) is a rare genetic syndrome that is mainly characterised by the association of cardiac and craniofacial anomalies together with others affecting the posterior fossa. PATIENTS AND METHODS: We report on 26 patients with Ritscher-Schinzel syndrome at a hospital in Medellin, in the Department of Antioquia, Colombia. RESULTS: Males account for 69% of this cohort. The mean age of the cohort was 30 months, and 42% were under the age of one year at the time of diagnosis. All of them presented ocular disorders, and megalocornea was the most frequent ocular manifestation (69%), whereas low-set ears (80.7%) and septal heart defects (68.7%) were the most common facial and cardiac malformations, respectively. The most frequent malformations of the posterior fossa were megacisterna magna (31.8%) and Dandy-Walker malformation (27%). 84% of the cases had delayed neurodevelopment or intellectual disability. Skeletal manifestations were frequent: the group consisting of camptodactyly, single palmar crease, overlapping fingers, vertical talus and nail hypoplasia were found in hands and feet in 96% of the cases. CONCLUSIONS: Ritscher-Schinzel syndrome is a heterogeneous syndrome from the genetic and clinical point of view. These results suggest that the skeletal and ocular abnormalities that were observed can facilitate the phenotypic diagnosis. However, it is necessary to conduct further studies that allow us to gain a deeper knowledge of its prevalence and help identify other genes involved in this syndrome.

TITLE: Descripcion fenotipica de 26 pacientes con sindrome de Ritscher-Schinzel (displasia craneo-cerebelo-cardiaca o sindrome 3C).Introduccion. El sindrome de Ritscher-Schinzel (tambien conocido como displasia craneo-cerebelo-cardiaca o sindrome 3C) es un sindrome genetico raro que se caracteriza principalmente por la asociacion de anomalias cardiacas, craneofaciales y de la fosa posterior. Pacientes y metodos. Se describen 26 pacientes con sindrome de Ritscher-Schinzel pertenecientes a un hospital de Medellin en el departamento de Antioquia, Colombia. Resultados. La presente cohorte esta compuesta en un 69% por hombres. La mediana de edad de la cohorte fue de 30 meses y el 42% tenia menos de 1 año de edad en el momento del diagnostico. Todos presentaban afectacion ocular, y la megalocornea fue la manifestacion ocular mas frecuente (69%), mientras que las orejas de implantacion baja (80,7%) y los defectos cardiacos septales (68,7%) fueron las malformaciones faciales y cardiacas mas comunes, respectivamente. Las malformaciones de la fosa posterior mas frecuentes fueron megacisterna magna (31,8%) y malformacion de Dandy-Walker (27%). El 84% tenia retraso del neurodesarrollo o discapacidad intelectual. Las manifestaciones esqueleticas fueron frecuentes: el conjunto de camptodactilia, pliegue palmar unico, dedos sobrelapados, astragalo vertical e hipoplasia ungueal en las manos y los pies se hallo en el 96% de los casos. Conclusiones. El sindrome de Ritscher-Schinzel es heterogeneo desde el punto de vista genetico y clinico. Estos resultados sugieren que las anormalidades esqueleticas y oculares observadas pueden facilitar el diagnostico fenotipico. No obstante, es necesario realizar estudios adicionales que permitan conocer mejor su prevalencia y facilitar la identificacion de otros genes implicados en este sindrome.