Galactose-deficient IgA1 in African Americans with IgA nephropathy: serum levels and heritability

Autor: Robert J. Wyatt, M. Colleen Hastings, Ali G. Gharavi, Kim R. McGlothan, Bruce A. Julian, Zina Moldoveanu, John T. Sanders, Jan Novak
Rok vydání: 2010
Předmět:
Immunoglobulin A
Male
Glycosylation
Heredity
Epidemiology
Biopsy
Urine
Critical Care and Intensive Care Medicine
urologic and male genital diseases
Gastroenterology
fluids and secretions
Risk Factors
Young adult
Child
Fisher's exact test
Aged
80 and over
biology
Age Factors
Middle Aged
Pedigree
Up-Regulation
Phenotype
Nephrology
symbols
Female
Adult
medicine.medical_specialty
Adolescent
chemical and pharmacologic phenomena
Risk Assessment
Nephropathy
symbols.namesake
Young Adult
stomatognathic system
Internal medicine
medicine
Humans
Genetic Predisposition to Disease
Risk factor
Aged
Transplantation
business.industry
Case-control study
Galactose
Glomerulonephritis
IGA
Original Articles
Heritability
medicine.disease
Black or African American
Endocrinology
Case-Control Studies
biology.protein
business
Protein Processing
Post-Translational
Biomarkers
Zdroj: Clinical journal of the American Society of Nephrology : CJASN. 5(11)
ISSN: 1555-905X
Popis: Background and objectives: Serum levels of galactose-deficient IgA1 (Gd-IgA1) are elevated and heritable in Caucasian and Asian patients with IgA nephropathy (IgAN), but have not been characterized in African Americans (AA). Our objective was to determine whether serum Gd-IgA1 levels are increased in AA patients with IgAN and whether this is a heritable trait in this group. Design, setting, participants, & measurements: Blood and urine samples were obtained from 18 adult and 11 pediatric AA patients with biopsy-proven IgAN and from 34 of their first-degree relatives. Healthy controls included 150 Caucasian adults, 65 AA adults, 45 Caucasian children, and 49 AA children. Serum total IgA and Gd-IgA1 levels were measured in patients and controls. Significant differences between patient and control groups for serum total IgA, Gd-IgA1, and ratio of Gd-IgA1/total IgA were determined by the Mann-Whitney U test. Heritability was calculated using SOLAR. Results: After stratifying by age, 7 of 11 pediatric and 9 of 18 adult AA patients with IgAN had serum Gd-IgA1 levels above the 95th percentile for age-appropriate AA controls. For first-degree relatives, the serum Gd-IgA1 level was >95th percentile for 1 of 8 when the patient's level was 95th percentile (P = 0.116, Fisher exact test). Heritability was 0.74 (P = 0.007). Conclusions: Serum levels of Gd-IgA1 are often elevated in AA patients with IgAN and their first-degree relatives. Thus, aberrant IgA1 glycosylation is a heritable risk factor for IgAN in African Americans.
Databáze: OpenAIRE
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