Open AccessDensity Gradient Purification of Mononuclear Cells Is Associated with Spurious (Artifactual) Immunosuppression
Author(s) -
Dazhong Xu,
Edwin A. Deitch,
Kevin Sittig,
Lü Qi,
John C. McDonald
Publication year - 1988
Publication title -
annals of surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.153
H-Index - 309
eISSN - 1528-1140
pISSN - 0003-4932
DOI - 10.1097/00000658-198812000-00016
Subject(s) - peripheral blood mononuclear cell , differential centrifugation , density gradient , medicine , immunosuppression , lymphocyte , in vitro , immunology , antigen , population , centrifugation , microbiology and biotechnology , biology , biochemistry , physics , environmental health , quantum mechanics
Mononuclear cells isolated by density gradient centrifugation from the peripheral blood of burn patients, but not healthy volunteers, are contaminated with large numbers of nonmononuclear cells. These contaminating leukocytes could cause artifactual alterations in standard in vitro tests of lymphocyte function. Thus, we compared the in vitro blastogenic response of density gradient purified leukocytes and T-cell purified lymphocytes from 13 burn patients to mitogenic (PHA) and antigenic stimuli. The mitogenic and antigenic response of the patients' density gradient purified leukocytes were impaired compared to healthy volunteers (p less than 0.01). However, when the contaminating nonlymphocytes were removed, the patients' cells responded normally to both stimuli. Thus, density gradient purified mononuclear cells from burn patients are contaminated by leukocytes that are not phenotypically or functionally lymphocytes. Since the lymphocytes from burn patients respond normally to PHA and alloantigens after the contaminating nonlymphocyte cell population has been removed, it appears that in vitro assays of lymphocyte function using density gradient purified leukocytes may give spurious results.