The epidemiology and clinical feature of selective immunoglobulin a deficiency of Zhejiang Province in China

Abstract

Background Selective immunoglobulin A deficiency (SIgAD) is the most common primary antibody deficiency disease and frequently reported in the Western countries. However, large‐scale epidemiologic studies on SIgAD in China are still lacking. Methods The clinical information of 555 180 subjects (age >4 years) including the outpatient, inpatient, and healthy subjects who had ordered serum immunoglobulin A, G, M in 9 hospitals of Zhejiang Province in China was collected. The SIgAD individuals were defined as IgA level <0.07 g/L with normal levels of serum IgG and IgM, whose age should be over 4 years, and any other secondary diseases causing SIgAD were also excluded. Then, the geographical and prevalence distribution of SIgAD individuals in Zhejiang Province and patients' clinical characteristics at the time of diagnosis were also reviewed. Result Among these 555 180 subjects who had ordered the immunoglobulin evaluation, the prevalence of SIgAD was 109/555180 (0.02%). The ratio of male to female of these SIgAD individuals was 1:1.37, which also included 87 adults (≥18 years) and 22 children (18 > age >4 years). For adults, the common clinical features were infections (43/87, 49.43%), autoimmune disorders (31/87, 35.63%), allergic cases (5/87, 5.75%), and tumor cases (4/87, 4.60%). Additionally, infectious diseases (20/22, 90.91%), autoimmune disorders (4/22, 18.18%), and allergic cases (1/22, 4.55%) were found in 22 children. Conclusion We first describe a large cohort of SIgAD individuals of Zhejiang Province in China. The incidence was 0.020%. The common clinical features were infection, autoimmune disorders, tumor, and allergy, and the infection rate was higher in children than the adults.

Clinical manifestation for immunoglobulin A deficiency: a systematic review and meta-analysis

“…Interestingly, despite former studies insisting on encapsulated bacteria such as Streptococcus pneumonia and Haemophilus influenza [ 26 ], we detected fungal pathogens as the major invading agents (18.5%) highlighting the role of secretory IgA in mucosal immunity against fungi [ 28 ]; thus, it could be assumed that fungi are underacknowledged pathogens in SIgAD and patients with a definite diagnosis might benefit from fungal screening. Additionally, the rate of infection considerably varied in different studies; some reported lower [ 19 , 25 , 29 – 31 ] or higher [ 16 , 23 , 32 , 33 ] prevalence of infection than our pooled data. These controversial results could stem from the fact that many individuals may only represent mild infections and therefore not be screened for immunodeficiency.…”

“…The prevalence of at least one allergic disease was determined in 16 different studies and fluctuated from 5.50% by Junwu Zhang, et al from China (95% CI: 0.020–0.116) [ 19 ] to 68.25% by Mohammadinejad P, et al, from Iran (95% CI: 0.553–0.794) [ 16 ]. The pooled prevalence of at least one allergic disease in the 1,274 study population was 29.16% (95% CI: 20.17, 39.01%; I2 = 91.9%) ( Fig.…”

Memory B cells and serum immunoglobulins are associated with disease severity and mortality in patients with COVID-19

“…However, the virus may cross the epithelial barrier if there is a high density of viral particles or a defect in mucosal immunity, which is reflected in reduced IgA levels. 30 31 A strong positive correlation between selective IgA deficiency (SIgAD) and COVID-19 infection has been reported worldwide. In Japan, where SIgAD is rare, SARS-CoV-2 infection and mortality rates are low.…”

“…Anti-SARS-CoV-2 monoclonal IgA binds to the viral spike protein and blocks receptor binding via competitive inhibition; the antibody can neutralise the virus on mucosal surfaces before it enters the cells. However, the virus may cross the epithelial barrier if there is a high density of viral particles or a defect in mucosal immunity, which is reflected in reduced IgA levels 30 31. A strong positive correlation between selective IgA deficiency (SIgAD) and COVID-19 infection has been reported worldwide.…”

Relationship between Selective IgA Deficiency and COVID-19 Prognosis

“…However, the virus may cross the epithelial barrier if there is a high density of viral particles or a defect in mucosal immunity, which is reflected in reduced IgA levels. The virus can infect epithelial cells, and other cells such as macrophages, via interaction of the receptor-binding domain (RBD) with the ACE-2 determinant of the spike protein (9,13,14).…”