title: CD14, CD16 and HLA-DR reliably identifies human monocytes and their subsets in the context of pathologically reduced HLA-DR expression by CD14(hi) /CD16(neg) monocytes: Expansion of CD14(hi) /CD16(pos) and contraction of CD14(lo) /CD16(pos) monocytes in acute liver failure.
abstract: Changes in monocytes and their subsets (CD14(hi)/CD16(neg), CD14(hi)/CD16(pos) and CD14(lo)/CD16(pos)) have been described in several diseases. The combination of CD14, CD16 and HLA-DR has been suggested to discriminate monocytes from the CD16(pos) /HLA-DR(neg) NK-cells and neutrophils but no data exist whether this strategy can be used in situations when monocyte HLA-DR expression is pathologically reduced. Monocytes and their subsets were concurrently identified through negative (exclusion of CD66b(pos) neutrophils, CD56(pos) NKcells, CD19(pos) B-cells, and CD3(pos) T-cells) and positive gating (inclusion of monocytes by expression of CD14, CD16, and HLA-DR) strategies on 30 occasions [9 healthy controls (HC) and 21 patients with conditions associated with low monocyte HLA-DR expression]. Bland-Altman and Passing and Bablok regression statistics did not demonstrate any significant measurement bias between the two strategies of monocyte identification. Monocyte subset phenotype was then compared in 18 HC and 41 patients with acute liver failure (ALF). Compared with HC, in ALF, the percentage of CD14(hi)/CD16(pos) monocytes was higher (7% vs 4%) whilst the percentage of CD14(lo)/CD16(pos) was lower (1.9% vs. 7%) (P ≤ 0.001); HLA-DR and CD86 MFIs on all monocyte subsets were lower, whilst CCR5, CD64, and CD11b MFIs were higher (P < 0.05). The relative expression by monocyte subsets of HLA-DR, CCR2, CCR5, CX3CR1, and CD11a was similar in ALF patients and HCs. Repeat analysis of an identical antibody-fluorochrome "backbone" targeting HLA-DR, CD14, and CD16 was assessed in 189 samples across 5 different experiments. There was excellent agreement in the results obtained using the positive gating strategy (interclass correlation coefficients > 0.8). Monocytes and their subsets can be reliably identified using an antibody-fluorochrome "backbone" of HLA-DR, CD14, and CD16. CD16(pos) monocytes continue to constitutively express HLA-DR even in conditions where HLA-DR is pathologically reduced on CD14(hi)/CD16(neg) monocytes. Understanding the changes in monocyte pheontype in ALF and similar clinico-pathological diseases may allow the development of novel biomarkers or therapeutic strategies.
authors: Department of Transplantation, Immunology and Mucosal Biology, Institute of Liver Studies and Transplantation, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, United Kingdom. robin.abeles@kcl.ac.uk
authors: Robin Daniel
authors: RD
authors: Abeles
authors: Mark J
authors: MJ
authors: McPhail
authors: David
authors: D
authors: Sowter
authors: Charalambos G
authors: CG
authors: Antoniades
authors: Nikhil
authors: N
authors: Vergis
authors: Godhev K Manakkat
authors: GK
authors: Vijay
authors: Emmanuel
authors: E
authors: Xystrakis
authors: Wafa
authors: W
authors: Khamri
authors: Debbie L
authors: DL
authors: Shawcross
authors: Yun
authors: Y
authors: Ma
authors: Julia A
authors: JA
authors: Wendon
authors: Diego
authors: D
authors: Vergani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression / Q000276:immunology; D020869:Gene Expression Profiling; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D007958:Leukocyte Count; D018950:Lipopolysaccharide Receptors / Q000235:genetics / Q000276:immunology*; D017114:Liver Failure, Acute / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000145:classification / Q000276:immunology* / Q000473:pathology; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology*
chemical_list: D015415:Biomarkers; D006684:HLA-DR Antigens; D018950:Lipopolysaccharide Receptors; D017452:Receptors, IgG