Defective Treg generation and increased type 3 immune response in leukocyte adhesion deficiency 1

In 15 Turkish LAD-1 patients and controls, we assessed the impact of pathogenic ITGB2 mutations on Th17/Treg differentiation and functions, and innate lymphoid cell (ILC) subsets. The percentage of peripheral blood Treg cells, in vitro-generated induced Tregs differentiated from naive CD4⁺ T cells were decreased despite the elevated absolute counts of CD4⁺ cells in LAD1 patients. Serum IL-23 levels were elevated in LAD1 patients. Post-curdlan stimulation, LAD1 patient-derived PBMCs produced more IL-17A. Additionally, the percentages of CD18-deficient Th17 cells expanded from total or naïve CD4⁺ T cells were higher. The blood ILC3 subset was significantly elevated in LAD1. Finally, LAD1 PBMCs showed defects in trans-well migration and proliferation and were more resistant to apoptosis. Defects in de novo generation of Tregs from CD18-deficient naïve T cells and elevated Th17s, and ILC3s in LAD1 patients' peripheral blood suggest a type 3-skewed immunity and may contribute to LAD1-associated autoimmune symptoms.

Alteration in humoral immunity is common among family members of patients with common variable immunodeficiency

BACKGROUND

The prevalence of primary immunodeficiency (PID) in the relatives of patients with common variable immunodeficiency (CVID) and IgA deficiency is high. Allergic disorders have been recorded in patients with humoral immunodeficiency. We aimed to determine the frequency of humoral immunodeficiency and atopy in the relatives of patients with CVID.

METHODS

The study population comprised 20 CVID patients and their relatives. All relatives were screened using a questionnaire covering demographic characteristics, warning signs of PID (adults and children), and core questions on asthma, rhinitis, and eczema from the International Study of Asthma and Allergies in Childhood (ISAAC). We also recorded absolute neutrophil and lymphocyte counts, serum immunoglobulin levels, pulmonary function values, and skin prick test results.

RESULTS

The study sample comprised 20 patients with CVID (15 males, 5 females; mean (SD] age, 16.4 (9] years) and 63 first-degree relatives (18 mothers, 16 fathers, 16 sisters, 10 brothers, and 3 offspring). The rate of parental consanguinity was 75%. Of 17 family members with positive PID warning signs, 6 had concomitant hypogammaglobulinemia (3 low IgM levels, 2 selective IgA deficiency, and 1 partial IgA deficiency). The ISAAC questionnaire revealed allergic rhinitis in 3 mothers, asthma in 2 fathers, and 1 sibling. Skin prick testing revealed sensitization to aeroallergens in 31.6% of cases in addition to 1 parent and 1 sibling.

CONCLUSIONS

Almost half of the 20 families with a CVID patient had at least 1 additional member with hypogammaglobulinemia, leading us to recommend routine screening for relatives of CVID patients.