title: Occupational exposure to formaldehyde and alterations in lymphocyte subsets.
abstract: BACKGROUND
  Formaldehyde is used in many occupational settings, most notably in manufacturing, health care, and embalming. Formaldehyde has been classified as a human carcinogen, but its mechanism of action remains uncertain.
  
  
  METHODS
  We carried out a cross-sectional study of 43 formaldehyde-exposed workers and 51 unexposed age and sex-matched controls in Guangdong, China to study formaldehyde's early biologic effects. To follow up our previous report that the total lymphocyte count was decreased in formaldehyde-exposed workers compared with controls, we evaluated each major lymphocyte subset (i.e., CD4(+) T cells, CD8(+) T cells, natural killer [NK] cells, and B cells) and T cell lymphocyte subset (CD4(+) naïve and memory T cells, CD8(+) naïve and memory T cells, and regulatory T cells). Linear regression of each subset was used to test for differences between exposed workers and controls, adjusting for potential confounders.
  
  
  RESULTS
  Total NK cell and T cell counts were about 24% (P = 0.037) and 16% (P = 0.0042) lower, respectively, among exposed workers. Among certain T cell subsets, decreased counts among exposed workers were observed for CD8(+) T cells (P = 0.026), CD8(+) effector memory T cells (P = 0.018), and regulatory T cells (CD4(+) FoxP3(+) : P = 0.04; CD25(+) FoxP3(+) : P = 0.008).
  
  
  CONCLUSIONS
  Formaldehyde-exposed workers experienced decreased counts of NK cells, regulatory T cells, and CD8(+) effector memory T cells; however, due to the small sample size; these findings need to be confirmed in larger studies.
authors: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland 20892-7240, USA. hosgoodd@mail.nih.gov
authors: H Dean
authors: HD
authors: Hosgood
authors: Luoping
authors: L
authors: Zhang
authors: Xiaojiang
authors: X
authors: Tang
authors: Roel
authors: R
authors: Vermeulen
authors: Zhenyue
authors: Z
authors: Hao
authors: Min
authors: M
authors: Shen
authors: Chuangyi
authors: C
authors: Qiu
authors: Yichen
authors: Y
authors: Ge
authors: Ming
authors: M
authors: Hua
authors: Zhiying
authors: Z
authors: Ji
authors: Senhua
authors: S
authors: Li
authors: Jun
authors: J
authors: Xiong
authors: Boris
authors: B
authors: Reiss
authors: Songwang
authors: S
authors: Liu
authors: Kerry X
authors: KX
authors: Xin
authors: Mariko
authors: M
authors: Azuma
authors: Yuxuan
authors: Y
authors: Xie
authors: Laura Beane
authors: LB
authors: Freeman
authors: Xiaolin
authors: X
authors: Ruan
authors: Weihong
authors: W
authors: Guo
authors: Noe
authors: N
authors: Galvan
authors: Aaron
authors: A
authors: Blair
authors: Laiyu
authors: L
authors: Li
authors: Hanlin
authors: H
authors: Huang
authors: Martyn T
authors: MT
authors: Smith
authors: Nathaniel
authors: N
authors: Rothman
authors: Qing
authors: Q
authors: Lan
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects* / Q000032:analysis; D001402:B-Lymphocytes / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D002617:Chemical Industry; D003430:Cross-Sectional Studies; D005260:Female; D005557:Formaldehyde / Q000009:adverse effects* / Q000032:analysis; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism; D016014:Linear Models; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000378:metabolism*; D008297:Male; D016555:Matched-Pair Analysis; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D005557:Formaldehyde