Chronic lung inflammation in victims of toxic gas leak at Bhopal

Persistent effects of chlorine inhalation on respiratory health

Chlorine gas is a toxic respiratory irritant that is considered a chemical threat agent because of the potential for release in industrial accidents or terrorist attacks. Chlorine inhalation damages the respiratory tract, including the airways and distal lung, and can result in acute lung injury. Some individuals exposed to chlorine experience a full recovery from acute injury, whereas others develop persistent adverse effects, such as respiratory symptoms, inflammation, and lung-function decrements. In animal models, chlorine can produce persistent inflammation, remodeling, and obstruction in large or small airways, depending on species. Airways with pseudostratified epithelia are repaired efficiently, with surviving basal epithelial cells serving as progenitor cells that repopulate the complement of differentiated cell types. Distal airways lacking basal cells are repaired less efficiently, leading to chronic inflammation and fibrosis at these sites. Persistent chlorine-induced airway disease in humans is treated with asthma medication to relieve symptoms. However, such treatment does not ameliorate the underlying disease pathogenesis, so treatments that are more effective at preventing initial development of airway disease after irritant gas exposure and at reversing established disease are needed.

Annual change in spirometric parameters among patients affected in Bhopal gas disaster: A retrospective observational study

Background:

The involvement of respiratory system due to inhalation of methyl isocyanate (MIC) during Bhopal gas disaster was particularly severe. We retrospectively evaluated the annual changes in spirometric parameters among those who were affected in this disaster (exposed survivors) and had respiratory symptoms.

Materials and Methods:

Spirometry reports of exposed survivors that were carried out in our institution were retrospectively reviewed and we identified 252 subjects who had performed spirometry at least twice with interval of more than one year. The annual changes in spirometric indices of them were calculated.

Results:

The average age of study population was 55.7 years and 72% were male. Annual decline of FEV₁ ≥ 40 ml/yr was observed among 48% exposed survivors. The mean annual decline of FEV₁ among symptomatic exposed survivors with initial normal spirometry was 91 ml (95% CI: 52 ml to 130 ml) and this was more than the patients with initial obstructive pattern. Among fifty four patients with initial normal spirometry, ten patients (18.5%) developed obstructive and two patients (5%) developed restrictive lung function abnormalities during follow up spirometry.

Conclusion:

The exposed survivors with chronic respiratory symptoms had accelerated decline in lung function and they are at higher risk of developing obstructive lung function.

Association of microsatellite instability and chronic obstructive pulmonary disorder in isocyanate-Exposed population of Bhopal

CONTEXT:

Survivors of the Bhopal gas disaster still suffer from various respiratory ailments. We examined the effects of exposures among a cross-section of current residents suffering from COPD by ISSR-PCR.

AIMS:

Molecular screening of the gas-affected population of Bhopal with COPD for microsatellite instability due to exposure of MIC.

SETTINGS AND DESIGN:

The isocyanate-exposed population of Bhopal city suffering from chronic obstructive pulmonary disorder.

MATERIALS AND METHODS:

Inter-(SSR) analysis was used to characterize microsatellite instability in 52 MIC victims of Bhopal, suffering from COPD using (CA)₈RG and (CA)₈R[Y-Q] primer.

STATISTICAL ANALYSIS USED:

Association analyses were performed using regression analysis.

RESULTS:

The study on the MIC-affected population in Bhopal showed weak association between microsatellite instability and age (r = + 0.37); exposure distance from site (r = −0.44); and smoking status(r = + 0.12); while regression analysis of the above parameters displayed supporting evidence.

CONCLUSIONS:

The high prevalence of smoking coupled with aging and poor living habits threatens, to further increase COPD incidences among this population, highlighting the need for enhanced screening efforts.

Pathology of small airways disease

CONTEXT

The term small airways disease encompasses a generally poorly understood group of lung diseases that may arise primarily within the small airways or secondarily from diseases primarily affecting the bronchi or lung parenchyma. Their histology may be confusing; however, because treatments and prognoses vary, correct pathologic diagnosis is important.

OBJECTIVE

To present a nonexhaustive review of the pathology of primary and secondary small airways diseases, including small airways disease related to tobacco; to various other exposures, including mineral dusts; to diseases involving other areas of the lung with secondary bronchiolar involvement; and to recently described bronchiolitic disorders.

DATA SOURCES

Current literature is reviewed.

CONCLUSIONS

Small airways diseases include a wide variety of diseases of which the pathologist must consider. Uncommon conditions such as diffuse idiopathic neuroendocrine cell hyperplasia and diffuse panbronchiolitis may show relatively specific diagnostic features histologically; however, most small airways diseases exhibit nonspecific histologic features. Conditions not considered primary pulmonary diseases, such as collagen vascular diseases, bone marrow transplantation, and inflammatory bowel disease, must also be considered in patients with small airways changes histologically. Clinical and radiologic correlation is important for obtaining the best possible diagnosis.

Treatment issues in interstitial lung disease in tropical countries

Management of interstitial lung disease, especially idiopathic pulmonary fibrosis, is both difficult and unsatisfactory. In many patients, only supportive therapy can be instituted. Attempts have been made to use anti-inflammatory therapy to reverse inflammation, provide symptomatic relief, stop disease progression, and prolong survival; the results of such treatment have varied from no improvement to significant prolongation of survival. Corticosteroids are the most frequently used anti-inflammatory agents. Cytotoxic drugs, such as oral azathioprine or intermittent intravenous cyclophosphamide, have also been shown to be effective both alone and in combination with low-dose oral corticosteroids. Of the other antifibrotic drugs that have been used, colchicine seems to provide some benefit. It is especially useful in aged persons and those with corticosteroid-induced problems or concomitant illnesses that are likely to be worsened by steroids. Anti-inflammatory therapy is costly to administer and monitor, particularly in the developing world. It is therefore important to consider these issues before instituting treatment. Younger patients and patients with less-severe disease of recent onset are most likely to respond to treatment. Similarly, patients with lymphocytic alveolitis or desquamative interstitial pneumonia respond better. Despite the use of newer strategies for treatment, the overall prognosis for patients with interstitial lung disease has not really changed, and the median population survival remains almost the same as it was about 30 years ago.