ABSTRACT
Severe combined immunodeficiencies (SCID) are a heterogeneous group of genetic disorders characterized by a blockade or impairment of both cellular and humoral immunity. Several epidemiological studies in different geographic areas have shown that the most common type of SCID affecting almost half of these patients is the X-linked common γ-chain (γ(c)) deficiency. The objective of the study was to document the incidence and types of SCID in our area. We conducted a retrospective analysis of patients who were diagnosed with SCID in the major immunology center in Greece for a 20-year period. During the study period, 30 children from 27 unrelated families with final diagnosis of SCID were identified. The incidence of SCID in Greece is estimated at 1.7 cases per 100,000 live births. Out of 30 children, 19 were boys (63.3%) and 26 (86.7%) had Greek maternal origin. Lymphocyte immunophenotypes that were identified were T(-)B(-)NK(+) in 12 (40%) children, T(-)B(+)NK(-) in six (20%), T(-)B(+)NK(+) in three (10%), T(-)B(-)NK(-) in two (6.7%) and T(+)B(+/-)NK(+) in seven (23.4%) (among them, four [13.4%] females with Omenn's syndrome). Molecular diagnosis was available for 12 children: γ(c) (2) with non Greek maternal origin, Jak3 (2), Rag1 (2), Artemis (3), ADA deficiency (2), PNP deficiency (1). Out of the 26 children of Greek maternal origin diagnosed with SCID representing 23 distinct families, only two (8.7%) had lymphocyte immunophenotype compatible with γ(c)-chain gene mutation (no molecular testing or enough DNA was available for them at the time of diagnosis). Findings of the present study suggest that, for unknown reasons, mutations of the γ(c) chain of several cytokine receptors have a rare occurrence in our area.
Subject(s)
Interleukin Receptor Common gamma Subunit/metabolism , X-Linked Combined Immunodeficiency Diseases/epidemiology , X-Linked Combined Immunodeficiency Diseases/genetics , Child , Child, Preschool , DNA Mutational Analysis , Demography , Family , Female , Genetics, Population , Greece , Humans , Immunophenotyping , Incidence , Infant , Infant, Newborn , Interleukin Receptor Common gamma Subunit/genetics , Male , Mutation/genetics , Retrospective Studies , X-Linked Combined Immunodeficiency Diseases/diagnosis , X-Linked Combined Immunodeficiency Diseases/immunologyABSTRACT
Primary immunodeficiency disease (PID) is a rare disorder in adults. Most often, serious forms are detected during infancy or childhood. However, mild forms of PID may not be diagnosed until later in life, and some types of humoral immunodeficiency may occur in adulthood. The purpose of this study was to identify clinical features of PID in Korean adults. A retrospective study was performed on 55 adult patients who were diagnosed as PID between January 1998 and January 2009 at a single tertiary medical center in Korea. IgG subclass deficiency was the most common phenotype (67%, 37/55), followed by total IgG deficiency (20%, 11/55), IgM deficiency (7%, 4/55), common variable immunodeficiency (2%, 1/55), and X-linked agammaglobulinemia (2%, 1/55). IgG3 and IgG4 were the most affected subclasses. Upper and lower respiratory tract infections (76%) were the most frequently observed symptoms, followed by multiple site infection (11%), urinary tract infection, and colitis. Bronchial asthma, rhinitis, and several autoimmune diseases were common associated diseases. IgG and IgG subclass deficiency should be considered in adult patients presenting with recurrent upper and lower respiratory infections, particularly in those with respiratory allergies or autoimmune diseases.
Subject(s)
IgG Deficiency/diagnosis , Immunologic Deficiency Syndromes/diagnosis , Adolescent , Adult , Aged , Cohort Studies , Common Variable Immunodeficiency/diagnosis , Common Variable Immunodeficiency/epidemiology , Female , Humans , Hyper-IgM Immunodeficiency Syndrome/diagnosis , Hyper-IgM Immunodeficiency Syndrome/epidemiology , IgG Deficiency/classification , IgG Deficiency/epidemiology , Immunologic Deficiency Syndromes/complications , Immunologic Deficiency Syndromes/epidemiology , Male , Middle Aged , Phenotype , Republic of Korea/epidemiology , Respiratory Tract Infections/etiology , Retrospective Studies , X-Linked Combined Immunodeficiency Diseases/diagnosis , X-Linked Combined Immunodeficiency Diseases/epidemiologyABSTRACT
INTRODUCTION: X-linked agammagobulinemia (XLA) is a primary immunodeficiency disorder caused by Bruton's tyrosine kinase (Btk) gene mutation. Recent studies suggested genotype-phenotype correlation in XLA, but a definitive association remains controversial. PATIENTS AND METHODS: We examined the relationship between specific Btk gene mutations and severity of clinical presentation in 62 patients with XLA. Disease severity was assessed by the age of disease onset and the presence of severe infections, while mutations were classified into severe and mild based on structural and functional consequence by bioinformatics analysis. RESULTS: Fifty-six Btk mutations were identified in 62 patients from 57 kindreds. Variation in phenotypes was observed, and there was a tendency of association between genotype and age of disease onset as well as occurrence of severe infections. CONCLUSION: A critical analysis of the circumstances upon presentation also revealed that under-recognition of recurrent infections and relevant family history are important hurdles to timely diagnosis of XLA.
