Need for National Registries in Rare Diseases, The

To the Editor:

Humbert and colleagues, in their new article, have published results from the national registry of pulmonary arterial hypertension (PAH) in France (1) Beyond the interesting data regarding the demographics and functional characteristics of the patients listed in the study, allowing the comparison with the national registry from the United States, which was published in the early 1990 through D'Alonzo and coworkers (2), the proportion of the different disease subtype (i.e., idiopathic, associated with connective tissue diseases, or related to portal hypertension) indicates a lock opener feature of national registries in rare diseases: the data raise the possibility of better allocation of medical and research resources. individual clear example of this is the prevalence of pulmonary hypertension in association with schistosomiasis in developing countries. For example, a novel study from two reference center in Brazil (3 4) which included schistosomiasis-related pulmonary hypertension together with other causes of PAH, rest that about 30% of the cases of PAH could be associated with schistosomiasis. This astonishing proportion, besides being a clear result of social conditions in many parts of the political division should, more importantly, draw the attention of researchers and clinicians to a regional characteristic that exigencys to he addressed and also that straits to be considered when extrapolating diagnostic and treatment algorithms to particular populations (5 6) This merit of Humbert and coworkers' article could be extrapolated to many other rare or orphan diseases whose regional distribution or characteristics should be considered at the time of the implementation of health policies.

Conflict of Interest Statement: None of the authors has a financial relationship with a commercial entity that has an interest in the subdue of this manuscript.

ROG?‰RIO SOUZA

CARLOS JARDIM

CARLOS CARVALHO

University of S??o Paulo Medical place of education

S??o Paulo, Brazil

Reference

1 Humbert M Sitbon O Chaouat A, Bertocchi M Habib G Gressin V Yaici A, Weitzenblum E Cordier J-F Chabot F et al. Pulmonary arterial hypertension in France: arises from a national registry. Am J Respir Crit Care M 2006;173:1023-1030

2 D'Alonzo GE Barst RJ Ayres SM Bergolsky EH Brundage BH Detre KM Fishman AP, Goldring RM woodlands RM, Kernis JT, et al. Survival in patients with primary pulmonary hypertension. arises from a national prospective registry. Ann Intern M 1991;115:343-349

3 Lapa M Ferreira EM Jardim C Martins B Arakaki JSO Souza R Clinical characteristic's of pulmonary hypertension patients in 2 relation centers in Sao Paulo. Rev Assoc M Bras (In press)

4 Lapa M Ferreira EM Jardim C Martins B Arakaki JSO Souza R Pulmonary hypertension in sum of two units reference centers in Brazil: the importance of schistosomiasis as a differential diagnosis [abstract]. Proc Am Thorac Soc 2006;3:A418.

5 Barst RJ McGoon M Torbicki A, Sitbon O Krowka MJ Olschewski H Gaine s Diagnosis and differential assessment of pulmonary arterial hypertension. J Am Coll Cardiol 2004;43:40S-47

6 Galie N Torbicki A, Barst R Dartevelle P Haworth s Higenbottam T, Olsehewski H, Peacock A, Pietra G Rubin LJ et al. Guidelines upon diagnosis and treatment of pulmonary arterial hypertension. The Task Force upon Diagnosis and Treatment of Pulmonary Arterial Hypertension of the European Society of Cardiology. Eur Heart J 2004;25:2243-2278

From the Authors

We thank Souza and colleagues for their make comments [i]or[/i] remarkss on our recent article (1) individual of our goals was to describe the clinical, functional, and hemodynamic characteristics for pulmonary arterial hypertension (PAH) in a 1-year period (from October 2002 to October 2003) Approximately half the cases corresponded to idiopathic, familial, and anorexigen-associalcd PAH, and half were associated with various diseases (connective tissue diseases, congenital heart disease, portal hypertension, and HIV infection). The pure burden of pulmonary hypertension in France is certainly abundant higher, as the French registry focused upon PAH only, therefore excluding patients with pulmonary hypertension owed to more common conditions similar as chronic hypoxemia and thromboembolic pulmonary disease (2)

Importantly, pulmonary hypertension may complicate prevalent conditions in other parts of the world. As stated by the agency of Souza and coworkers in their alphabetic character recent information indicates that schistosomiasis is a major cause of pulmonary hypertension in Brazil, as well as in other developing countries, highlighting the ne for specific research and care in this area (3) Other risk factors, including sickle confined apartment disease (4), HIV infection (5) and remedy exposure (5), may also contribute to the weight of the condition in many countries. novel reports indicate that pulmonary hypertension is a significant complication of sickle confined apartment disease, underlining the need for specific studies to better characterize and treat these patients (4) Moreover, the prevalence of PAH in HIV-infected bring under rules is around 0.5% in France and Switzerland, suggesting that it may indeed cause large numbers of (mostly unrecognized) cases in many countries (5) Finally, in all senses to fenfluramine derivatives was a major PAH risk factor in France in the 1980s-1990 upon the basis of this information, health authorities withdrew these medicines from the market in the late 1990 (5)