Inborn errors of immunity and mortality: 10 years of single-center experience

The aim of this study was to investigate the mortality rate and causes of death among patients with rare inborn errors of immunity (IEI), conditions associated with relatively high morbidity and mortality, who were followed at our center, and to identify management strategies tailored to local conditions based on the findings.

The medical records of 99 patients followed between January 1, 2015, and October 1, 2025, were retrospectively reviewed. Data on age, sex, symptom onset, and date of diagnosis were recorded, and diagnostic delay was calculated. Systemic symptoms and clinical findings observed at admission and during the disease course were documented. Laboratory parameters, including lymphocyte counts, B-cell and memory B-cell levels, as well as IgG and IgG4 levels, were analyzed.

A total of 99 patients were included in the study. Of the participants, 53.5% were male (n = 53) and 46.5% were female (n = 46). The mean age was 34.8 ± 14.9 years (range, 17-72 years). The most common infection was pneumonia (n = 38, 38.4%). Evaluation of presenting symptoms at diagnosis showed that respiratory manifestations were the most frequent (n = 56, 56.6%). Twelve patients died, while 87 survived. Among the nonsurvivors, 58.3% (n = 7) died due to infection-related causes and 41.7% (n = 5) due to malignancy. The diagnostic delay was 4 years in survivors and 9 years in nonsurvivors. Although no statistically significant differences were observed between survivors and nonsurvivors in terms of lymphocyte counts, B-cell percentage, IgG, and IgG4 levels, all laboratory parameters were numerically lower in patients who died. Similarly, diagnostic delay was longer in non-survivors.