Sauropus androgynus-constrictive obliterative bronchitis/bronchiolitis--histopathological study of pneumonectomy and biopsy specimens with emphasis on the inflammatory process and disease progression

DLI Induced by Herbal Medicine: What Are the Characteristics of DLI due to Herbal Medicines?

In many countries, herbal medicine has been developed and is currently practiced. Herbal medicine involves the use of the stalks, roots, leaves, flowers, and berries of several different plant species for medical treatment. Many practitioners believe that herbal medication has no side effects because of its natural origin. Thus, herbal medication has been used for a long time with little awareness of its side effects. However, there is an increasing incidence of interstitial pneumonia due to a drug-induced lung injury (DLI), which could be induced by common drugs. Moreover, increasing cases of bronchiolitis obliterans and pulmonary hypertension are being reported; further, these are drug-induced conditions. Clinicians should be more aware of DLI symptoms caused by herbal medication and interrogate patients regarding their use of herbal medication and supplements as well as prescription drugs.

Sauropus androgynus (L.) Merr. Induced Bronchiolitis Obliterans: From Botanical Studies to Toxicology

Sauropus androgynus L. Merr. is one of the most popular herbs in South Asia, Southeast Asia, and China where it was known as a slimming agent until two outbreaks of pulmonary dysfunction were reported in Taiwan and Japan in 1995 and 2005, respectively. Several studies described that the excessive consumption of Sauropus androgynus could cause drowsiness, constipation, and bronchiolitis obliterans and may lead to respiratory failure. Interestingly, this herb has been used in Malaysia and Indonesia in cooking and is commonly called the “multigreen” or “multivitamin” plant due to its high nutritive value and inexpensive source of dietary protein. The plant is widely used in traditional medicine for wound healing, inducing lactation, relief of urinary disorders, as an antidiabetic cure and also fever reduction. Besides these medicinal uses, the plant can also be used as colouring agent in food. This review will explore and compile the fragmented knowledge available on the botany, ethnobotany, chemical constitutes, pharmacological properties, and toxicological aspects of this plant. This comprehensive review will give readers the fundamental, comprehensive, and current knowledge regarding Sauropus androgynus L. Merr.

Aqueous fraction of Sauropus androgynus might be responsible for bronchiolitis obliterans

BACKGROUND AND OBJECTIVE

Bronchiolitis obliterans (BO) has been reported to develop following ingestion of Sauropus androgynus (SA), a leafy shrub distributed in Southeast Asia. Little is known about direct effects of SA on airway resident cells or haematopoietic cells in vitro. Identification of the SA component responsible for the development of BO would be an important key to elucidate its mechanism. We sought to elucidate the direct effects of SA on airway resident cells or haematopoietic cells and identify the SA element responsible for the pathogenesis of BO.

METHODS

SA dry powder was partitioned into fractions by solvent extraction. Human and murine monocytic cells, epithelial cells and endothelial cells were cultured with SA solution or fractions eluted from SA. We also investigated the effect of SA in vivo using a murine BO syndrome (BOS) model.

RESULTS

The aqueous fraction of SA induced significant increases of inflammatory cytokine and chemokine production from monocytic lineage cells. This fraction also induced significant apoptosis of endothelial cells and enhanced intraluminal obstructive fibrosis in allogeneic trachea allograft in the murine BOS model. We found individual differences in tumour necrosis factor α (TNF-α) production from monocytes of healthy controls stimulated by this aqueous fraction of SA, whereas it induced high-level TNF-α production from monocytes of patients with SA-induced BO.

CONCLUSIONS

These results suggest that an aqueous fraction of SA may be responsible for the pathogenesis of BO.

Pulmonary function change in patients with Sauropus androgynus-related obstructive lung disease 15 years later

BACKGROUND/PURPOSE

Little is understood about the clinical course and prognosis of patients with Sauropus androgynus-related obstructive lung disease. The aim of this study was to investigate their clinical manifestations and pulmonary function change 15 years after the acute episode.

METHODS

A descriptive, observational study of patients with S androgynus-related obstructive lung disease, diagnosed 15 years ago, was conducted. We evaluated their pulmonary function and the Modified Medical Research Council (MMRC) dyspnea scale. Saint George's Respiratory Questionnaire (SGRQ) was also performed. Age- and forced expiratory volume in one second (FEV1)-matched chronic obstructive pulmonary disease (COPD) patients were used as a reference group for comparison of clinical manifestations.

RESULTS

Twenty-nine of 49 patients, diagnosed at our hospital 15 years ago, could be contacted. Four patients died and one patient was ventilator-dependent. Sixteen patients were willing to come to our hospital to have pulmonary function and questionnaire evaluation. The FEV1 of these patients declined only 1.6 ± 21.6 mL/year over a 15-year period. Meanwhile, the severity of their dyspnea and their health-related quality of life were better than age- and FEV1-matched COPD patients as shown by the MMRC dyspnea scale (1.4 ± 0.8 vs. 2.0 ± 1.0; p = 0.037) and symptom domain of the SGRQ (32.6 ± 18.4 vs. 43.5 ± 20.3; p = 0.006).

CONCLUSION

After an acute deterioration, patients with S androgynus-related obstructive lung disease had a stationary pulmonary function over a period of 15 years, and their clinical manifestations were less severe than age- and FEV1-matched COPD patients. A further study with a larger sample size may be needed to confirm these findings.

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.

Bronchiolar disorders: a clinical-radiological diagnostic algorithm

Bronchiolar disorders are generally difficult to diagnose because most patients present with nonspecific respiratory symptoms of variable duration and severity. A detailed clinical history may point toward a specific diagnosis. Pertinent clinical questions include history of smoking, collagen vascular disease, inhalational injury, medication usage, and organ transplant. It is important also to evaluate possible systemic and pulmonary signs of infection, evidence of air trapping, and high-pitched expiratory wheezing, which may suggest small airways involvement. In this context, pulmonary function tests and plain chest radiographs may demonstrate abnormalities; however, they rarely prove sufficiently specific to obviate bronchoscopic or surgical biopsy. Given these limitations, in our experience, high-resolution CT (HRCT) scanning of the chest often proves to be the most important diagnostic tool to guide diagnosis in these difficult cases, because different subtypes of bronchiolar disorders may present with characteristic image findings. Three distinct HRCT patterns in particular are of value in assisting differential diagnosis. A tree-in-bud pattern of well-defined nodules is seen primarily as a result of infectious processes. Ill-defined centrilobular ground-glass nodules point toward respiratory bronchiolitis when localized in upper lobes in smokers or subacute hypersensitivity pneumonitis when more diffuse. Finally, a pattern of mosaic attenuation, especially when seen on expiratory images, is consistent with air-trapping characteristic of bronchiolitis obliterans or constrictive bronchiolitis. Based on an appreciation of the critical role played by HRCT scanning, this article provides clinicians with a practical algorithmic approach to the diagnosis of bronchiolar disorders.

Apoptosis and necrosis are involved in the toxicity of Sauropus androgynus in an in vitro study

BACKGROUND/PURPOSE

The raw juice of the young sticks and leaves of Sauropus androgynus (SA) has been widely used as a natural food for body weight reduction and vision protection in Taiwan and Southeast Asia. But as has been reported, SA-associated obliterative bronchiolitis can develop after taking SA for more than 3 months. Lung transplantation was carried out in severe cases.

METHODS

To study the toxic effect, we separated the SA extract into three parts, namely CHCl3, EtOAc and n-BuOH fractions, using polarity dissection. NIH3T3 fibroblasts were treated with the SA fractions 300 microg/mL and subjected to a series of cytotoxic assays.

RESULTS

The EtOAc fraction exhibited the strongest effect of cell growth inhibition, followed by the CHCl3 and n-BuOH fractions. Features of condensed chromatin and apoptosis were observed in cells exposed to n-BuOH and EtOAc fractions using fluorescence microscopy. Formation of DNA ladders was also observed in the above cells. Instead, the CHCl3 fraction induced DNA smearing. In bivariate dot plots of annexin V and propidium iodide double staining, necrosis and apoptosis appeared in cells treated with CHCl3 and n-BuOH fractions, respectively, and a mixed type of necrosis and apoptosis appeared in EtOAc fraction-treated cells.

CONCLUSION

Our results indicate that necrosis and apoptosis are involved in the toxic effect of SA in NIH3T3 fibroblasts. More evidence is needed to clarify if necrosis and apoptosis are also related to the pathogenesis of SA-associated obliterative bronchiolitis.

Challenges in pulmonary fibrosis. 2: Bronchiolocentric fibrosis

Bronchiolocentric fibrosis is essentially represented by the pathological pattern of constrictive fibrotic bronchiolitis obliterans. The corresponding clinical condition (obliterative bronchiolitis) is characterised by dyspnoea, airflow obstruction at lung function testing and air trapping with characteristic mosaic features on expiratory high resolution CT scans. Bronchiolitis obliterans may result from many causes including acute diffuse bronchiolar damage after inhalation of toxic gases or fumes, alloimmune chronic processes after lung or haematopoietic stem cell transplantation, or connective tissue disease (especially rheumatoid arthritis). Airway-centred interstitial fibrosis and bronchiolar metaplasia are other features of bronchiolocentric fibrosis.

Bronchiolar disorders

Bronchiolar abnormalities are relatively common and occur in a variety of clinical settings. Various histopathologic patterns of bronchiolar injury have been described and have led to confusing nomenclature with redundant and overlapping terms. Some histopathologic patterns of bronchiolar disease may be relatively unique to a specific clinical context but others are nonspecific with respect to either etiology or pathogenesis. Herein, we present a scheme separating (1) those disorders in which the bronchiolar disease is the predominant abnormality (primary bronchiolar disorders) from (2) parenchymal disorders with prominent bronchiolar involvement and (3) bronchiolar involvement in large airway diseases. Primary bronchiolar disorders include constrictive bronchiolitis (obliterative bronchiolitis, bronchiolitis obliterans), acute bronchiolitis, diffuse panbronchiolitis, respiratory bronchiolitis, mineral dust airway disease, follicular bronchiolitis, and a few other rare variants. Prominent bronchiolar involvement may be seen in several interstitial lung diseases, including hypersensitivity pneumonitis, respiratory bronchiolitis-associated interstitial lung disease, cryptogenic organizing pneumonia (idiopathic bronchiolitis obliterans organizing pneumonia), and pulmonary Langerhans' cell histiocytosis. Large airway diseases that commonly involve bronchioles include bronchiectasis, asthma, and chronic obstructive pulmonary disease. The clinical relevance of a bronchiolar lesion is best determined by identifying the underlying histopathologic pattern and assessing the correlative clinico-physiologic-radiologic context.