Eosinophilic lung disease in the tropics

Loeffler's syndrome mimicking lung tumor and pneumonia in a child: A case report

Loeffler's syndrome is a rare and benign eosinophilic pneumonia which is commonly transient and self-limiting. Herein we report a 12-year-old boy who presented with dry cough, hemoptysis, chest pain, no fever and diminished breath sounds on the right lung. Chest imaging showed a consolidation lesion with bronchograms in the right upper and middle lobes, accompanied by a right free-flowing pleural effusion. Laboratory studies showed elevated C-reactive protein levels, and an eosinophil count of 13.7%. A lung biopsy was performed to diagnose the Loeffler's syndrome. The patient's condition was improving significantly with antibiotic therapy and is now followed up closely.

Surgery for parasitic lung infestations: roles in diagnosis and treatment

Pulmonary parasitic infestations are a worldwide problem associated with significant morbidity and socioeconomic impact. They are known to have varied clinical presentations and radiological appearances. Prevention of parasite transmission and medical treatment of cases form the two pillars of control of these diseases. The role of surgery is limited to the diagnosis and definitive treatment of the minority of pulmonary parasitic afflictions, most notably hydatidosis. Despite surgery being established as the treatment of choice in pulmonary hydatid cysts (PHCs) for over half a century, variations and unresolved controversies persist regarding the best surgical technique. Complications brought on by cyst rupture, multiplicity and multi-organ involvement add complexity to treatment decisions. The development of video-assisted thoracoscopic surgery (VATS) brings the promise of reduced peri-operative morbidity but is yet to be universally accepted as a safe technique. In this review, we endeavor to discuss the common pulmonary infestations focusing on the current trends and controversies surrounding surgery for PHC.

Parasitic Diseases of the Lung

Parasitic infection is a major healthcare problem that affects millions of the world’s population. Immigration and global warming have changed the natural distribution of parasitic diseases far removed from endemic areas. The respiratory system can be affected by a broad spectrum of helminthic and protozoal parasitic diseases. The diagnosis of parasitic infection of the respiratory system may be delayed due to myriad clinical and radiographic presentations of parasitic diseases which make the diagnosis of these entities challenging. Pulmonologists need to be familiar with the epidemiology, clinical presentation, pathophysiology, and bronchoscopic findings of parasitic lung diseases, in order to provide proper management in a timely fashion. This review provides a comprehensive view of both helminthic and protozoal parasitic diseases that affect the respiratory system, especially the central airways.

Parasitic pneumonia and lung involvement

Parasitic infestations demonstrated a decline in the past decade as a result of better hygiene practices and improved socioeconomic conditions. Nevertheless, global immigration, increased numbers of the immunocompromised people, international traveling, global warming, and rapid urbanization of the cities have increased the susceptibility of the world population to parasitic diseases. A number of new human parasites, such as Plasmodium knowlesi, in addition to many potential parasites, have urged the interest of scientific community. A broad spectrum of protozoal parasites frequently affects the respiratory system, particularly the lungs. The diagnosis of parasitic diseases of airway is challenging due to their wide varieties of clinical and roentgenographic presentations. So detailed interrogations of travel history to endemic areas are critical for clinicians or pulmonologists to manage this entity. The migrating adult worms can cause mechanical airway obstruction, while the larvae can cause airway inflammation. This paper provides a comprehensive review of both protozoal and helminthic infestations that affect the airway system, particularly the lungs, including clinical and roentgenographic presentations, diagnostic tests, and therapeutic approaches.

Effects of respiratory syncytial virus infection and major basic protein derived from eosinophils in pulmonary alveolar epithelial cells (A549)

RSV (respiratory syncytial virus)-induced pneumonia and bronchiolitis may be associated with hyperresponsive conditions, including asthma. Eosinophilic proteins such as MBP (major basic protein) may also be associated with the pathophysiology of asthma. To elucidate the roles of RSV infection and MBP in the pathogenesis of pneumonia with hyperresponsiveness, we investigated the effects of RSV infection and MBP on A549 (alveolar epithelial) cells. CPE (cytopathic effects) in A549 cells were observed by microscopy. Apoptosis and cell death was evaluated by flow cytometric analysis and modified MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. We also measured 15 types of cytokines and chemokines in A549 cell supernatants. Although RSV alone did not affect the CPE of A549, high concentrations of MBP resulted in cell death within 24 h. Combinations of RSV and MBP synergistically induced cell death. In A549 cells infected with RSV alone, the release of GM-CSF (granulocyte-macrophage colony-stimulating factor) was significantly enhanced compared with control cells (no infection). In the cells treated with MBP alone, the production of IL (interleukin)-2, 4, 5, 7, 10, 12, 13, 17, IFN (interferon)-γ, GM-CSF, G-CSF (granulocyte colony-stimulating factor) and MIP (macrophage inflammatory protein)-1β was significantly increased compared with control cells. Notably, the levels of GM-CSF and IL-17 in RSV/MBP-treated cells were significantly higher than those treated with MBP alone. These results suggest that MBP synergistically enhanced the release of various cytokines/chemokines and the cell death of RSV-infected A549 cells, indicating that MBP may be closely associated with the pathophysiology of allergic reactions in bronchiolitis/pneumonia due to RSV.

Imaging of Parasitic Diseases of the Thorax

A broad spectrum of parasitic infections frequently affects the lungs, mediastinum, and thoracic wall, manifesting with abnormal imaging findings that often make diagnosis challenging. Although most of these infections result in nonspecific abnormalities, familiarity with their imaging features and the diagnostic pathways help the radiologist to formulate an adequate differential diagnosis and to guide diagnosticians in reaching a definitive diagnosis.

Bronchial lavage in tropical pneumonias

PURPOSE OF REVIEW

In developing countries, where resources are scarce, it is paramount that the clinician be familiar with the most cost-effective diagnostic and therapeutic modalities available. The fiberoptic bronchoscope is an expensive piece of equipment, but can be an economical diagnostic tool in tropical pneumonias. The role of bronchoalveolar lavage is discussed in this review.

RECENT ADVANCES

Since its introduction in the 1970s, particularly in developing countries, bronchoalveolar lavage has become an important tool for diagnosis, assessing the activity and monitoring a large number of pulmonary diseases. The importance of bronchoalveolar lavage is becoming even more apparent since the emergence of the HIV/AIDS epidemic, which has changed the face of many pulmonary diseases, especially tropical ones.

SUMMARY

Bronchoalveolar lavage is useful in developed and developing countries alike, for assessing many bacterial, fungal, and parasitic pulmonary diseases.

Strongyloides Stercoralis Hyperinfection in Systemic Lupus Erythematosus and the Antiphospholipid Syndrome

OBJECTIVE

The Strongyloides stercoralis hyperinfection syndrome (SHS) may develop in individuals with asymptomatic infection receiving immunosuppressive treatment. This report summarizes current knowledge regarding SHS in patients with systemic lupus erythematosus (SLE) and associated antiphospholipid syndrome (APS).

METHODS

Two patients with active SLE and associated APS presenting with SHS are reported. Additional cases of strongyloidiasis in SLE were identified and reviewed.

RESULTS

Patient 1: A 34-year-old woman with SLE and APS characterized by active glomerulonephritis, stroke, and several hospital-acquired infections presented with vomiting and diffuse abdominal pain. Intestinal vasculitis was suspected, and treatment with methylprednisolone and cyclophosphamide was given. Response was partial. A gastric biopsy revealed S. stercoralis larvae. She received ivermectin and eventually recovered. Patient 2: A 37-year-old man with active glomerulonephritis and APS with recurrent thrombosis presented with digital necrosis. Necrotizing vasculitis was suspected and treated with immunosupressants. He suddenly developed respiratory failure secondary to alveolar hemorrhage and bronchoalveolar lavage was performed. The patient developed Gram-negative septic shock and died. The postmortem result of bronchoalveolar lavage yielded Strongyloides larvae. Nine cases of strongyloidiasis and the SHS in SLE patients reported in the literature were identified and reviewed. Five of these patients died; none had associated APS.

CONCLUSIONS

These cases suggest that the SHS can exacerbate SLE and APS, predisposing to Gram-negative sepsis and death. Immunocompromised patients need an early diagnosis and specific treatment of parasitic diseases and their complications. The SHS should be considered in the differential diagnosis of lupus complications in patients from endemic areas.

Parasitic diseases of the respiratory tract

PURPOSE OF REVIEW

The human pulmonary system can be affected by a variety of parasites. This review focuses on the most common parasitic infestations involving the lung, except for protozoon disease.

RECENT FINDINGS

In many parasitic lung conditions, the clinical manifestations and the imaging findings are non-specific and can make diagnosis challenging. Hydatid disease and paragonimiasis involve the lung directly. Chronic schistosomiasis can lead to pulmonary hypertension. Strongyloides stercoralis infestation is capable of transforming into a fulminant fatal disease. In many types of nematode infestations, the pulmonary phase can cause acute eosinophilic pneumonia. Chest radiographs of patients with paragonimiasis and dirofilariasis can cause diagnostic confusion. Cases of tropical pulmonary eosinophilia typically present with refractory bronchial asthma. Most of these diseases are initially diagnosed by detecting eggs or larvae in stool, sputum, pleural fluid or tissue, and are confirmed by serologic testing. Cystic hydatid disease generally requires surgical treatment, whereas almost all other parasitic lung conditions can be treated medically.

SUMMARY

Although most parasites that affect the lung are endemic to tropical and subtropical regions, immigration and travel practices have resulted in transfer of these diseases to other areas. It is important for physicians to know the epidemiologic characteristics, clinical presentations, and treatments of choice for these conditions.