B Lymphocytes in Human Subcutaneous Adipose Crown‐Like Structures

• Published in: Obesity (Silver Spring, Md.) Vol. 20; no. 7; pp. 1372 - 1378
• Main Authors: McDonnell, Marie E., Ganley‐Leal, Lisa M., Mehta, Ankeeta, Bigornia, Sherman J., Mott, Melanie, Rehman, Qasim, Farb, Melissa G., Hess, Donald T., Joseph, Lija, Gokce, Noyan, Apovian, Caroline M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2012
• Subjects: Adult; Antigens, CD19 - metabolism; B-Lymphocytes - immunology; B-Lymphocytes - pathology; Blood Glucose - metabolism; Body fat; Body Mass Index; Female; Glycated Hemoglobin - metabolism; Humans; Immunohistochemistry; Insulin Resistance; Lymphocytes; Male; Obesity; Obesity - immunology; Obesity - pathology; Omentum - immunology; Omentum - pathology; Predictive Value of Tests; Subcutaneous Fat - pathology
• ISSN: 1930-7381; 1930-739X; 1930-739X
• DOI: 10.1038/oby.2012.54

Accumulation of macrophages and T cells within crown‐like structures (CLS) in subcutaneous adipose tissue predicts disease severity in obesity‐related insulin resistance (OIR). Although rodent data suggest the B cell is an important feature of these lesions, B cells have not been described within the human CLS. In order to identify B cells in the human subcutaneous CLS (sCLS) in obese subjects and determine whether the presence of B cells predict insulin resistance, we examined archived samples of subcutaneous and omental fat from 32 obese men and women and related findings to clinical parameters. Using immunohistochemistry, we identified B (CD19+) and T cells (CD3 +) within the sCLS and perivascular space. The presence and density of B cells (B cells per high‐power field (pHPF), T cells pHPF, and B cell:T cell (B:T) ratio) were compared with measures of insulin resistance (homeostasis model assessment (HOMA)) and other variables. In 16 of 32 subjects (50%) CD19+ B cells were localized within sCLS and were relatively more numerous than T cells. HOMA was not different between subjects with CD19+ vs. CD19− sCLS (5.5 vs. 5.3, P = 0.88). After controlling for diabetes and glycemia (hemoglobin A1c (HbA1c)), the B:T ratio correlated with current metformin treatment (r = 0.89, P = 0.001). These results indicate that in human OIR, B cells are an integral component of organized inflammation in subcutaneous fat, and defining their role will lead to a better understanding of OIR pathogenesis and potentially impact treatment.