Glutaraldehyde-induced occupational asthma: BALF components and BALF and serum Clara cell protein (CC16) changes due to specific inhalatory provocation test

Levels of Clara cell secretory protein and surfactant protein A in municipal solid waste management workers in Ibadan, Southwest Nigeria

Toxic pneumonitis and related respiratory symptoms are common among waste management workers (WMWs). Products of different cellular responses following exposure to toxic components of wastes can lead to the production of a variety of biomolecules. There is a growing recognition of the importance of biomarkers in risk assessment and a strong advocacy for their determination and use as indicators of health and safety. This study assessed the prevalence of respiratory symptoms and the relevance of pulmonary surfactant protein A (SP-A) and Clara cell 16 protein (CC16) as indicators of occupational inhalation exposure to toxic substances and irritants in WMW. A total of 172 subjects consisting of 112 WMWs and 60 Non-WMWs were recruited by purposive sampling. Data on socio-economic and work-related symptoms were collected using structured questionnaire. CC16 and SP-A were determined by ELISA in serum samples. Clinical history reveals a slightly higher prevalence of respiratory symptoms in WMWs relative to control subjects. Increased permeability of the lung-blood barrier, characterized by significant elevation of serum SP-A and serum CC16, was associated with respiratory symptoms in WMWs. Steady increases in SP-A and CC16, respectively, in relation to occupational duration were observed in WMWs relative to control. Receiver operating characteristic curve and multivariate analyses revealed SP-A and CC16 as important lung biomarkers for assessing sub-clinical effects of occupational exposure. Our data suggest SP-A and CC16 may be relevant indicators for assessing occupational inhalation exposure to toxic substances and irritants among WMWs.

CC16 as a Marker of COE-Induced the Early Change of Blood Composition of Coke Oven Workers: A Case Control Study

OBJECTIVE

This project aims to enhance the occupational health insurance for coke oven workers.

METHODS

A total of 136 coke oven emissions workers and 61 oxygen plant workers were recruited to receive physical examinations. The coke oven emissions concentration at the workplace was measured by weighing method. The CC16 concentration was detected by enzyme-linked immunosorbent assay.

RESULTS

Logistic regression analysis revealed that exposure to coke oven emissions was correlated with CC16. Correlation analysis revealed that CC16 was related to some physical examination indicators. Multivariate general linear models showed that CC16 was indeed positively correlated with albumin after adjusting for confounding factors.

CONCLUSIONS

Coke oven emissions affected multiple tissues and multiple systems. The blood system might be the earliest system affected and could be detected by the CC16 protein concentration.

Serum Clara cell secretory protein (CC-16) in non-smoking patients with obstructive sleep apnea

OBJECTIVE

This study aimed to determine the association between the severity of obstructive sleep apnea (OSA) and serum Clara cell protein (CC16) levels in non-smoking patients with OSA.

METHODS

This prospective study included non-smoking patients who presented with sleep-related disturbances and underwent polysomnography (PSG). The serum CC16 level was measured and its relationship to PSG parameters was investigated.

RESULTS

The study included 128 patients (83 men) with a mean age of 48.4 ± 11.9. OSA was detected in 66 men (70%) and 29 women (30%) (p = 0.051). The severity of OSA was mild in 32 (25%), moderate in 28 (22%), and severe in 35 (27%) of the patients. There was no significant difference in CC16 levels between the OSA group (1746 ± 1006) and the OSA negative group (1721 ± 1201, p = 0.91) levels. There was no significant difference between the CC16 levels of the each four groups. Mean serum CC16 levels were significantly lower in OSA negative men than OSA positive men (777 vs 1462, p = 0.005). No significant difference was observed in CC16 values according to OSA severity in women.

CONCLUSION

The serum CC16 level does not differ between non-smoking OSA patients and OSA negative patients.

Clara cell protein (CC16), a marker of lung epithelial injury, is decreased in plasma and pulmonary edema fluid from patients with acute lung injury

BACKGROUND

Acute lung injury (ALI) and ARDS are common clinical syndromes that are underdiagnosed. Clara cell secretory protein (CC16) is an antiinflammatory protein secreted by the Clara cells of the distal respiratory epithelium that has been proposed as a biomarker of lung epithelial injury. We tested the diagnostic and prognostic utility of CC16 in patients with non-trauma-related ALI/ARDS compared to a control group of patients with acute cardiogenic pulmonary edema (CPE).

METHODS

Plasma and pulmonary edema fluid samples were obtained from medical and surgical patients with ALI/ARDS or CPE requiring intubation for mechanical ventilation. The etiology of pulmonary edema was determined using consensus clinical criteria for ALI/ARDS and CPE and the edema fluid-to-plasma protein ratio. Plasma and edema fluid CC16 levels were measured by sandwich enzyme-linked immunosorbent assay. CC16 levels were log transformed for analysis, and comparisons were made by the Student t test or Chi(2) as appropriate.

RESULTS

Compared to patients with CPE (n = 9), patients with ALI/ARDS (n = 23) had lower median CC16 levels in plasma (22 ng/mL [interquartile range (IQR), 9 to 44 ng/mL] vs 55 ng/mL [IQR, 18 to 123 ng/mL], respectively; p = 0.053) and pulmonary edema fluid (1,950 ng/mL [IQR, 1,780 to 4,024 ng/mL] vs 4,835 ng/mL [IQR, 2,006 to 6,350 ng/mL], respectively; p = 0.044). Relative to total pulmonary edema fluid protein concentration, the median CC16 level was significantly lower in patients with ALI/ARDS (45 ng CC16/mg total protein [IQR, 4 to 64 ng CC16/mg total protein] vs 120 ng CC16/mg total protein [IQR, 87 to 257 ng CC16/mg total protein], respectively; p = 0.005). Neither plasma nor edema fluid CC16 levels predicted mortality, the number of days of unassisted ventilation, or ICU length of stay.

CONCLUSION

CC16 is a promising diagnostic biomarker for helping to discriminate ALI from CPE. Larger scale validation is warranted to better characterize the utility of CC16 in the diagnosis of this underrecognized syndrome.