Predictors of clara cell protein (CC16) level: an investigation of CC16 as a silica exposure biomarker

Details

• Personal Author:
  Borm P ; Castranova, Vincent ; Donaldson K ; Girdler-Brown B ; Gulumian M ; Murray J ; Vallyathan V ; Wilson K
• Description:
  Background and aims: Clara cell protein (CC16) is a protein that is mainly produced by Clara cells in the respiratory epithelium. CC16 can be measured in bronchoalveolar lavage specimens, serum, urine and sputum. Clara cells and CC16 may play a role in protecting the lung from oxidative stress. A change in CC16 reflects chronic damage to Clara cells and may therefore be a useful biomarker for crystalline silica induced lung damage. This paper presents an analysis of predictors of CC16 in gold miners exposed to silica and unexposed controls. Methods: 118 African male volunteers participated in this cross-sectional study. They were recruited from a gold mine (silica exposed, n= 64), a blood donor service (silica non-exposed n= 37) and a hospital HIV clinic (silica non-exposed n= 18). Data were collected on age, work history, smoking habits and HIV status. CC16 was assayed in the serum using an ELISA kit. Multiple linear regression was performed with post-regression residuals analysis to identify the factors that might explain the observed variation in CC16. Results: Arithmetic mean (AM), geometric mean (GM) and geometric standard deviation (GSD) for the whole group CC16 level were 6.0ng/ml, 5.27ng/ml and 1.67ng/ml. AM, GM, and GSD for the silica exposed group were 5.56, 4.87 and 1.69, and for the unexposed group were 6.49, 5.77 and 1.64. The CC16 results were log-normally distributed. T-tests for unpaired data with equal variance indicated a crude relationship between silica exposure and CC16 levels, p = 0.074; and smoking and CC16 levels, p = 0.0001. Multiple regression with the factors investigated in this study explained 20% of the variation (coefficient of determination r = 0.19) and the model identified exposure to silica as a significant risk for a lower level of CC16 (p = 0.024) smoking was no longer significant (p = 0.082). Discussion and conclusions: CC16 levels were lowered in silica exposed subjects and were not affected by HIV status. CC16 is a suitable candidate for further research. Factors that further explain the variance in CC16 levels need to be identified before it can be confidently used as a biomarker for silica dust exposure [Description provided by NIOSH]
• Subjects:
  Biomarkers Demography Epidemiology Lung Lung Diseases Men Occupational Health Race Factors Respiratory System Respiratory Tract Diseases Safety

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• Keywords:
  Cell Biology Cell Function Demographic Characteristics Humans Lung Cells Lung Disease Lung Disorders Oxidative Stress Proteins Racial Factors Sociological Factors Statistical Analysis

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• ISSN:
  1351-0711
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  65
• Issue:
  9
• NIOSHTIC Number:
  nn:20048343
• Citation:
  Occup Environ Med 2008 Sep; 65(9)(Suppl):167 Tu-P-4
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7) ; Silica (CAS RN 7631-86-9)
• Federal Fiscal Year:
  2008
• Peer Reviewed:
  False
• Source Full Name:
  Occupational and Environmental Medicine. EPICOH 2008
• Supplement:
  Suppl
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:fce4e91b641beac298a09e26f90a325acd4ef23bd7cd006aaba6d016e22befc57e2ec59a8eb7115e55da4006470787798ee362e28873b80c40f103b42dacf321
• Download URL:
  https://stacks.cdc.gov/view/cdc/203112/cdc_203112_DS1.pdf
• File Type:
  [PDF - 37.10 KB ]