To the Editor:
We read with interest the article by Bakst et al (October 1999), reporting the use of continuous IV epoprostenol in a patient with Gaucher's disease with pulmonary hypertension. The effective use of this therapeutic modality is encouraging. Pulmonary hypertension in patients with Gaucher's disease may be secondary to the effects of interstitial lung involvement or intercapillary plugging by Gaucher cells, or primary-like, in association with enzyme replacement therapy. Enzyme therapy may ameliorate pulmonary disease, including improvement in secondary pulmonary hypertension, as was initially observed in the cited case. Later reappearance of pulmonary hypertension may be associated with enzyme treatment.
We have a similar case of a 34-year-old woman who had undergone splenectomy, who presented with hypoxia and a tricuspid incompetence (TI) gradient of 27 mm Hg. After 3 years on enzyme therapy with improvement in hypoxemia, clubbing, and pulmonary function tests, the TI gradient dropped to 20 mm Hg (within the normal range). After 2 more years of treatment, she developed elevation of TI gradient to 37 mm Hg. We also documented another patient with Gaucher's disease, who started enzyme therapy with a TI gradient within the normal range, which then rose above 30 mm Hg with treatment with the placental derivative, alglucerase, and then returned to the normal range after withdrawal. Challenge with the recombinant form, imiglucerase, resulted in elevation of the TI gradient above 30 mm Hg, and treatment withdrawal again resulted in return to the normal range.
Continued use of enzyme replacement (and in very high dosage) in the case by Bakst et al could have been the cause of the reemergence of pulmonary hypertension, and enzyme withdrawal might be considered to wean her from lifelong dependence on epoprostenol. On the other hand, the success of epoprostenol may be of greater importance to patients who have other life-threatening features of Gaucher's disease and who cannot, therefore, terminate enzyme therapy. We applaud the pioneering efforts of Bakst et al, as like them, we are concerned with the increased number of patients with Gaucher's disease who develop pulmonary hypertension. In addition, we concur that echocardiography should be included in routine follow-up of all Gaucher patients, treated and untreated, despite the fact that, in recent guidelines for diagnosis and monitoring by the International Collaborative Gaucher Group registry, this procedure was unfortunately omitted.
Deborah Elstein, PhD Ari Zimran, MD Shaare Zedek Medical Center Jerusalem, Israel
Correspondence to: Ari Zimran, MD, Shaare Zedek Medical Center, P. O. Box 3235, Jerusalem 91031; Israel; e-mail: email@example.com
 Bakst AE, Gaine SP, Rubin LJ. Continuous intravenous epoprostenol therapy for pulmonary hypertension in Gaucher's disease. Chest 1999; 116:1127-1129
 Amir G, Ron N. Pulmonary pathology in Gaucher's disease. Hum Pathol 1999; 30:666-670
 Harats D, Pauzner R, Elstein D, et al. Pulmonary hypertension in two patients with type I Gaucher disease while on alglucerase therapy. Acta Haematol 1997; 98:47-50
 Elstein D, Klutstein MW, Lahad A, et al. Echocardiographic assessment of pulmonary hypertension in Gaucher's disease. Lancet 1998; 351:1544-1546
 Charrow J, Esplin JA, Gribble TJ, et al. Gaucher disease: recommendations on diagnosis, evaluation, and monitoring. Arch Intern Med 1998; 158:1754-1760
To the Editor:
We appreciate the comments by Drs. Elstein and Zimran. In light of their work suggesting a role for enzyme replacement in the pathogenesis of pulmonary hypertension in Gaucher's disease, we did indeed discontinue enzyme therapy; however, during this interval off enzyme replacement, our patient experienced worsening hepatomegaly, which subsided upon reinstitution of replacement therapy.
Lewis J. Rubin, MD, FCCP UCSD Healthcare San Diego, CA
Correspondence to: Lewis J. Rubin, MD, FCCP, Professor of Medicine, Director, Division of Pulmonary/Critical Care Medicine, UCSD Healthcare, 200 West Arbor Dr, San Diego, CA 92103-8372; e-mail: firstname.lastname@example.org
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