Browsing by Subject "Immunoglobulin A"

Now showing 1 - 3 of 3
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    Clinical characteristics and outcomes of autoimmune pancreatitis based on serum immunoglobulin G4 levels: A single-center, retrospective cohort study
    (Baishideng, 2023) Jaber, Fouad; Elfert, Khaled; Alsakarneh, Saqr; Beran, Azizullah; Jaber, Mohammed; Gangwani, Manesh Kumar; Abboud, Yazan; Medicine, School of Medicine
    Autoimmune pancreatitis (AIP) is a complex, poorly understood disease gaining increasing attention. "Clinical Characteristics and Outcome of AIP Based on Serum IgG4 levels," investigated AIP with a focus on serum immunoglobulin (Ig) G4 levels. The 213 patients with AIP were classified according to serum IgG4 levels: Abnormal (elevated) and normal. Patients with higher IgG4 levels exhibited a more active immune system and increased relapse rates. Beyond IgG4, the IgA levels and age independently contributed to relapse risk, guiding risk assessment and tailored treatments for better outcomes. However, limitations persist, such as no IgA correlation with IgG4 levels, absent data on autoantibody-positive AIP cases critical for Asian diagnostic criteria, and unexplored relapse rates in high serum IgG AIP by subtype. Genetic factors and family histories were not addressed. As the understanding and referral of seronegative AIPs increase, there's a growing need for commercially available, highly sensitive, and specific autoantibodies to aid in diagnosing individuals with low or absent serum IgG4 levels.
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    A comparison of IgA antibody levels in caries-resistant and caries-susceptible children
    (1993) Rose, Paul Todd; Hughes, Christopher V.; Avery, David R.; Sanders, Brian J.; Branca, Ronald A.; Gregory, Richard L.
    Secretory immunity is believed to play a role in natural resistance to dental caries. Although dental caries has dramatically decreased in children in the United States, there remains a population of caries-susceptible children even in fluoridated communities. Previous studies have shown a positive correlation between salivary immunoglobulin A (sIgA) antibody levels to Streptococcus mutans and caries resistance in adults. In the present study, an enzyme-linked immunosorbent assay (ELISA) was used to compare IgA antibody levels to S. mutans in saliva from 20 caries susceptible (DMFS greater than 5) and 20 caries-resistant (DMFS less than or equal to 1) children (ages 7-11). All subjects resided in fluoridated communities. Salivary S. mutans numbers were significantly higher (p ≤ 0.05) in the caries susceptible (31.2 percent of total streptococci) group than in the caries resistant (1.6 percent of total streptococci) group. Whole saliva from caries-resistant children had significantly higher (p = 0.05) levels of IgA antibodies to S. mutans than saliva from caries-susceptible children. However, whole saliva from caries-resistant children had similar levels of IgA1 or IgA2 antibodies against S. mutans to saliva from caries-susceptible children. These results suggest that IgA antibody to S. mutans may play a role in natural protection from dental caries in children and confirm previous reports indicating a role for salivary IgA antibodies to S. mutans in mediation of caries.
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    Innate and adaptive humoral responses coat distinct commensal bacteria with immunoglobulin A
    (Elsevier, 2015-09-15) Bunker, Jeffrey J.; Flynn, Theodore M.; Koval, Jason C.; Shaw, Dustin G.; Meisel, Marlies; McDonald, Benjamin D.; Ishizuka, Isabel E.; Dent, Alexander L.; Wilson, Patrick C.; Jabri, Bana; Antonopoulos, Dionysios A.; Bendelac, Albert; Department of Microbiology and Immunology, IU School of Medicine
    Immunoglobulin A (IgA) is prominently secreted at mucosal surfaces and coats a fraction of the intestinal microbiota. However, the commensal bacteria bound by IgA are poorly characterized and the type of humoral immunity they elicit remains elusive. We used bacterial flow cytometry coupled with 16S rRNA gene sequencing (IgA-Seq) in murine models of immunodeficiency to identify IgA-bound bacteria and elucidate mechanisms of commensal IgA targeting. We found that residence in the small intestine, rather than bacterial identity, dictated induction of specific IgA. Most commensals elicited strong T-independent (TI) responses that originated from the orphan B1b lineage and from B2 cells, but excluded natural antibacterial B1a specificities. Atypical commensals including segmented filamentous bacteria and Mucispirillum evaded TI responses but elicited T-dependent IgA. These data demonstrate exquisite targeting of distinct commensal bacteria by multiple layers of humoral immunity and reveal a specialized function of the B1b lineage in TI mucosal IgA responses.