Forma pseudoneoplásica de esquistossomose pulmonar crônica sem hipertensão pulmonar

Respiratory morbidity in Schistosoma mansoni infection: a rapid review of literature

Background

Schistosomiasis contributes to 2.5 million disability-adjusted life years globally. Acute and chronic respiratory morbidity of Schistosoma mansoni (S. mansoni) is poorly documented in the literature. We conducted a rapid literature review of the burden of respiratory symptoms and lung function abnormalities among patients with S. mansoni. We also report the immunologic and lung imaging findings from the studies reviewed.

Methods

We carried out a comprehensive literature search in Embase and MEDLINE from the inception of the databases to 13th March 2023.

Results

A total of 2243 patients with S. mansoni were reported from 24 case reports, 11 cross-sectional studies, 7 case series, 2 cohort studies and 2 randomized controlled trials. The prevalence of any respiratory symptom was 13.3-63.3% (total number of patients studied, n = 149). The prevalence of the individual symptoms among patients with S. mansoni in whom respiratory symptoms were sought for was as follows: cough (8.3-80.6%, n = 338), dyspnea (1.7-100.0%, n = 200), chest pain (9.0-57.1%, n = 86), sputum production (20.0-23.3%, n = 30) and wheezing (0.0 - 20.0%, n = 1396). The frequency of the symptoms tended to be higher in acute schistosomiasis. Restrictive lung disease was prevalent in 29.0% (9/31). The commonest chest imaging findings reported were nodules (20-90%, n = 103) and interstitial infiltrates (12.5-23.0%, n = 89). Peripheral blood eosinophilia was prevalent in 72.0-100.0% of patients (n = 130) with acute schistosomiasis and correlated with symptoms and imaging abnormalities. Three case reports in chronic S. mansoni reported elevated C-reactive protein, leucocyte, neutrophil and absolute eosinophil counts, eosinophil percentage, IgE and IgG4.

Conclusion

There is a high prevalence of respiratory morbidity among patients with S. mansoni, particularly in the acute stage of the infection, although the studies are relatively small. Larger studies are needed to characterize respiratory morbidity in chronic schistosomiasis and determine the underlying clinical and immunological mechanisms.

Schistosoma haematobium infection with pulmonary involvement in a traveller returning from Congo: A case report and systematic review of literature on nodular pulmonary schistosomiasis

BACKGROUND

Schistosomiasis is highly prevalent in sub-Saharan Africa and diagnosis is difficult for travel medicine practitioners, because it can affect different organs with atypical manifestations. S. haematobium is mostly associated with urinary involvement and rarely with pulmonary lesions. This review aims to summarise the pulmonary forms associated with schistosomiasis, especially with S. haematobium.

METHOD

Based on a case report of both pulmonary and urogenital schistosomiasis, we performed a systematic literature review of schistosomiasis occurring in migrants and travellers, with a specific focus on pulmonary schistosomiasis.

RESULTS

Pulmonary schistosomiasis can present two different clinical patterns. On the one hand, there is an acute pattern, which more frequently affects non-immune young travellers within three to eight weeks of their return and, on the other hand, there is a chronic pattern, which has been evolving in recent years and which mostly affects people living in endemic areas or migrating from these countries. Nodular pulmonary lesions are described in both patterns. Genus identification should not focus only on known patterns, and identification of S. haematobium should not be associated exclusively with urinary schistosomiasis.

CONCLUSIONS

Pulmonary schistosomiasis, even when resulting from S. haematobium, is a rare but existing infection that appears to be spreading with increasing travel and global migration. Physicians need to be more aware of non-specific symptoms that may reveal an atypical presentation of a tropical disease, in order to avoid the chronic complications which can result from parasitic diseases.

New Insights on Acute and Chronic Schistosomiasis: Do We Need a Redefinition?

A precise timeframe to differentiate acute schistosomiasis (AS) and chronic schistosomiasis (CS) is not well defined. Based on recent published literature, lung nodular lesions in AS and CS seem to have the same pathophysiology, that is, eggs laid in situ by adult worms, during an ectopic migration. Moreover, the occurrence of lung nodules due to clusters of eggs and the systemic immunoallergic reaction of AS (Katayama syndrome) may be two separate clinical entities, which may overlap during the early phase of infection. Consequently, the classical distinction between AS and CS loses much of its conceptual validity. If adult worms play a more important role in the early phase of the disease the clinical management of AS should probably be revised.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Radiographic and HRCT imaging findings of chronic pulmonary schistosomiasis: review of 10 consecutive cases

Objective:

To describe the chest radiography (CR) and the high resolution CT (HRCT) imaging findings of chronic pulmonary schistosomiasis (CPS)

Methods and materials:

This retrospective study included 10 patients suffering from CPS, studied between September 2013 and October 2016 by using CR and HRCT. Images were reviewed by two experienced radiologists in consensus, blinded to clinical data. A p value < 0.05 was considered significant

Results:

All the patients enrolled showed some abnormalities at HRCT, including lung consolidations, solid nodules, nodules with peri-nodular halo, ground-glass opacities, enlarged hilar lymph-nodes. Only seven patients showed findings at CR ( p = 0.001). At CT, none of the patients had significant pleural, vascular (pulmonary arteries) or cardiac findings. Post-therapy studies (mean interval 35 days) demonstrated the absence of residual disease in all patients.

Conclusion:

The imaging findings of CPS varied widely in our study population. HRCT may show signs which are occult on plain radiograph. All lesions disappeared after appropriate therapy at imaging follow-up studie.

Lipopolysaccharide-induced acute lung injury in mice chronically infected by Schistosoma mansoni

We used a murine model of Schistosoma mansoni (SM) infection and lipopolysaccharide (LPS)-induced endotoxicity to investigate if these conditions can interact to modify the pathological manifestations typically observed in each condition. Swiss mice were randomized into four groups: SAL, uninfected; SM, infected; LPS, uninfected + LPS; and SM + LPS, infected + LPS. S. mansoni infection developed over 120 days, after which blood samples and lungs were collected, peritoneal leukocytes were isolated and cultivated for 6 and 24 h after LPS inoculation (1 mL/kg). Infected animals presented marked granulomatous inflammation. LPS exposure transiently modified the profile of leucocyte migration into the lung tissue and increased NO production by isolated leukocytes, without inducing any acute effect on the structure of schistosomiasis granulomas. Beyond modifying lung morphology, S. mansoni and LPS interacted to modulate the circulating levels of cytokines. S. mansoni infection restricted INF-γ upregulation 6 and 24 h after LPS administration. Conversely, 24 h after inoculation, LPS increased IL-2 and IL-5 levels. Our findings indicate that LPS impaired the lung microenvironment by acutely disrupting inflammatory homeostatic mechanisms that control lung schistosomiasis. As schistosomiasis develops as a chronic condition, long-term exposure to endotoxins could aggravate the granulomatous process, an issue that requires further investigation.

Schistosomiasis-associated pulmonary hypertension

Schistosomiasis, a parasite-borne disease, is highly prevalent in Africa and Asia; it is estimated that close to 20 million people worldwide have a severe form of the disease. The chronic form can affect the gastrointestinal system and lead to hepatosplenic disease, and it may cause cardiopulmonary complications, including pulmonary hypertension. The exact pathogenesis of schistosomiasis-associated pulmonary hypertension (Sch-PH) remains unclear, although several mechanisms, including parasitic arterial embolization, pulmonary arteriopathy, and portopulmonary hypertension-like pathophysiology, have been suggested. The immunopathology of the disease is also unclear, although there are similarities with the immunology of idiopathic pulmonary arterial hypertension (PAH). Finally, the treatment of Sch-PH has not been well studied. There is some evidence on treating the underlying infection, with unclear effect on Sch-PH, and advanced PAH therapies are now being suggested, but more studies are needed to confirm their efficacy.