Letter by Lambertucci and Antunes Regarding Article, “Pulmonary Vascular Disease in the Developing World”
To the Editor:
We read with great interest the article by Butrous et al1, in which the authors presented a comprehensive review of pulmonary vascular disease in the developing world. Relative to pulmonary hypertension in schistosomiasis, however, it is important to further comment on some information presented by the authors.
The authors said, “Acute pulmonary schistosomiasis is also called Katayama syndrome.” In fact, it would be more appropriate to state that Katayama syndrome is a synonym for acute schistosomiasis, not acute pulmonary schistosomiasis.2
When the authors comment on the treatment of schistosomal pulmonary hypertension, they refer to an article published by our group: “Some investigators reported radiological improvement after specific treatment with oxamniquine in 40 patients with chronic S. mansoni.”3 In this study, we showed that some patients with chronic schistosomiasis mansoni, without pulmonary hypertension, treated with schistosomicides developed pulmonary radiological alterations a few days after the completion of treatment. These findings would be explained by dead worm embolism in the lungs or deposition of immune complexes in pulmonary vessels.
Under the heading, “The Pathology of Pulmonary Vascular Disease in Chronic Schistosomiasis,” Butrous and colleagues state that “Nearly all cases of Symmers’ fibrosis have portal vein thrombosis….” In the article quoted by the authors, an autopsy series, Cheever and Andrade4 gave a different number: “Portal thrombosis was noted in 12% of unoperated subjects…” More recently, the frequency of portal vein thrombosis in patients with hepatosplenic schistosomiasis has been shown to be ≈5% by imaging techniques such as ultrasound and magnetic resonance angiography of portal vessels.
The authors also wrote that “Schistosomal pulmonary vasculopathy is frequently seen with Symmers fibrosis; in those without Symmers fibrosis, portal hypertension is common.” Nevertheless, to our knowledge, without Symmers fibrosis portal hypertension related to schistosomiasis has not yet been reported.5
In summary, the authors are to be congratulated for their timely review of pulmonary vascular hypertension in developing countries. Physicians in Brazil and other countries will certainly appreciate this major contribution to the subject. The points raised in our letter intend to improve what is already a first-class appraisal of a difficult subject.