Retrospective analysis of patients with severe combined immunodeficiency and alternative diagnostic criteria: A 20-year single centre experience.

Severe combined immunodeficiency (SCID) is an inborn errors of immunity (IEI) disorder characterized by impairment in the development and function of lymphocytes and could be fatal if not treated with hematopoietic stem cell transplant in the first 2 years of life. There are various diagnostic criteria for SCID among different primary immunodeficiency societies. We retrospectively evaluated clinical and laboratory findings of 59 patients followed up with the diagnosis of SCID at our clinic over the past 20 years in order to develop an algorithm that would help diagnosis of SCID for the countries where a high ratio of consanguineous marriage is present because these countries have not launched TREC assay in their newborn screening programs. The mean age at diagnosis was 5.80 ± 4.90 months, and the delay was 3.29 ± 3.99 months. The most common complaint and physical examination findings were cough (29.05%), eczematous rash (63%) and organomegaly (61%). ADA (17%), Artemis (14%), RAG1/2 (15%), MHC Class II (12%) and IL-2R (12%) deficiencies were the most common genetic defects. Lymphopenia (87.5%) was the most frequent abnormal laboratory finding and below 3000/mm3 in 95% of the patients. The CD3+ T cell count was 300/mm3 and below in 83% of the patients. As a result, a combination of low lymphocyte count and CD3 lymphopenia for SCID diagnosis would be more reliable for countries with high rate of consanguineous marriage. Physicians should consider diagnosis of SCID in a patient presenting with severe infections and lymphocyte counts below 3000/mm3 under 2 years of age.

Evaluation of immunological abnormalities in patients with rare syndromes.

Introduction: Recurrent infections are important problems in syndromic patients. This study aimed to evaluate immunological abnormalities in patients who presented with recurrent infections and were diagnosed with rare syndromes. Material and methods: This retrospective analysis included 14 patients with complaints of recurrent infections, all of whom were diagnosed with a rare syndrome. Results: The study group consisted of patients with Aicardi syndrome, Brugada syndrome, Phelan- McDermid syndrome, trichothiodystrophy, LEOPARD syndrome, Prader-Willi syndrome, Seckel syndrome, trisomy 18 (Edwards' syndrome), Wiedemann-Steiner syndrome, West syndrome, Williams syndrome, 47,XYY syndrome, 16p13 deletion syndrome, and 13q1.3 deletion syndrome. Seven patients (50%) were girls and seven (50%) were boys (mean age, 56.7 ±32.9 months; median [range] age: 45.5 [27-153] months). There were high rates of consanguinity (50%), cesarean section delivery (71%), and hospitalization in the intensive care unit (78.5%). No patients had a family history of immunodeficiency. On admission, all patients exhibited humoral and/or cellular immune system abnormalities. During the follow-up period, all T-cell abnormalities were improved after immunoglobulin replacement therapy (IGRT), while B-cell abnormalities persisted. These findings suggested that the patients predominantly had antibody deficiencies associated with mild T-cell abnormalities because of recurrent infections. The rates of infections and hospitalizations were significantly reduced after IGRT (p < 0.001); the rate of intensive care unit admission also significantly decreased (from 78.5% to 21.4%). Two of the three oxygen-dependent patients exhibited improvement therein. IGRT was discontinued in two patients with significant clinical improvement during follow-up. Conclusions: An immunological evaluation should be considered in pediatric patients with rare syndromes and recurrent infections. IGRT may help to improve the prognoses of these patients.