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Assessment of in situ adipose tissue inflammation by microdialysis
Author(s) -
Langkilde Anne,
Andersen Ove,
Henriksen Jens H.,
Langberg Henning,
Petersen Janne,
EugenOlsen Jesper
Publication year - 2015
Publication title -
clinical physiology and functional imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.608
H-Index - 67
eISSN - 1475-097X
pISSN - 1475-0961
DOI - 10.1111/cpf.12134
Subject(s) - microdialysis , medicine , inflammation , adipose tissue , lipodystrophy , systemic inflammation , chemokine , immunology , pathology , human immunodeficiency virus (hiv) , antiretroviral therapy , viral load , central nervous system
Summary Background Inflammation, and specifically adipose tissue ( AT ) inflammation, is part of the pathophysiology of obesity and HIV ‐associated lipodystrophy. Local AT protein assessment methods are limited, and AT inflammation studies have therefore primarily examined inflammatory gene expression. We therefore investigated the utility of microdialysis to study in situ AT interstitial inflammatory protein levels. Material and Methods Abdominal subcutaneous AT microdialysis was performed in six healthy men, six HIV ‐infected men with lipodystrophy and six without lipodystrophy using the internal references 51 Cr‐ EDTA and 125 I‐human serum albumin. We measured 41 inflammatory proteins in microdialysis samples by L uminex technology, as well as systemic levels in 14 subjects. Furthermore, in vitro studies of the internal reference technique for microdialysis recovery of inflammatory proteins were made. Results We detected in situ AT interstitial levels of 14 inflammatory proteins by microdialysis, while the 27 other inflammatory proteins assessed were only detected sporadically. Initial levels of IL ‐6 and IL ‐8 were undetectable. Insertion trauma affected IL ‐1α, IL ‐6, IL ‐8, monocyte chemotactic factor ( MCP )‐1, IP ‐10, G‐ CSF , growth‐related oncogene ( GRO ), macrophage‐derived chemokine ( MDC ) and macrophage inflammatory protein ( MIP )‐1β levels, while fibroblast growth factor ( FGF )‐2 was not affected. Systemic and AT interstitial levels were poorly correlated. The microdialysis recovery of smaller proteins was higher than for larger, and the internal references improved microdialysis by accounting for variation in perfusion across the membrane. Conclusion Interstitial inflammatory proteins can be sampled in situ using microdialysis. Use of internal references improves the microdialysis technique. However, insertion trauma hampers the use of microdialysis to study AT inflammatory levels, except for FGF ‐2. Still, microdialysis gives unique insight to in situ AT interstitial concentrations.