Anemia

To the Editor:

John and colleagues reported in a recent issue of CHEST (March 2005) (1) a relatively high frequency of anemia in patients with COPD. However, they did not mention whether the studied population was in treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II type 1 (AT1) receptor blockers.

Several observations suggested that an intact and activated renin-angiotensin system may be an important determinant of erythropoiesis, (2,3) including a variety of clinical conditions such as hypertension, chronic renal insufficiency, heart failure, and COPD. (4) Consequently, the assumption of ACE inhibitors and AT1 receptor blockers has been shown to reduce hemoglobin concentrations both in healthy subjects (5) and in those with pathologic conditions. (4,6-8 Thus, therapy with ACE inhibitors and AT1 receptor blockers might have been a confounder in this study.

REFERENCES

(1) John M, Hoernig S, Doehner W, et al. Anemia and inflammation in COPD. Chest 2005; 127:825-829

(2) Mrug M, Stoppa T, Julian BA, et al. Angiotensin II stimulates proliferation of normal early erythroid progenitors. J Clin Invest 1997; 100:2310-2314

(3) Cole J, Ertoy D, Lin H, et al. Lack of angiotensin II-facilitated erythropoiesis causes anemia in angiotensin converting enzyme-deficient mice. J Clin Invest 2000; 106:1391-1398

(4) Marathias KP, Agroyannis B, Mavromoustakos T, et al. Hematocrit-lowering effect following inactivation of renin-angiotensin system with angiotensin converting enzyme inhibitors and angiotensin receptor blockers. Curr Top Med Chem 2004; 4:483-486

(5) Griffing GT, Melby JC. Enalapril (MK-421) and the white cell count and haematocrit [letter]. Lancet 1982; 1:1361

(6) Gaston RS, Julian BA, Diethelm AG, Curtis JJ. Effects of enalapril on erythrocytosis after renal transplantation. Ann Intern Med 1991; 115:954-955

(7) Plata R, Cornejo A, Arratia C, et al. Angiotensin-converting-enzyme inhibition therapy in altitude polycythaemia: a prospective randomised trial. Lancet 2002; 359:663-666

(8) Ishani A, Weinhandl E, Zhao Z, et al. Angiotensin-converting-enzyme inhibitor as a risk factor for the development of anemia, and the impact of incident anemia on mortality in patients with left ventricular dysfunction. J Am Coll Cardiol 2005; 45:391-399

Luca Mascitelli, MD

Comando Brigata Alpina "Julia"

Udine, Italy

Francesca Pezzetta, MD

Ospedale di San Vito al Tagliamento

San Vito al Tagliamento, Italy

Correspondence to: Luca Mascitelli, MD, Comando Brigata alpina "Julia", Sanitary Service, Via S. Agostino 8, Udine 33100, Italy; e-mail: lumasci@libero.it

To the Editor:

The author of this comment mentioned that therapy with angiotensin-converting enzyme (ACE) inhibitors might be a confounder in interpreting the results of our study. (1) In this patient population, 23 patients of the nonanemic group (88 patients) were treated with ACE inhibitors or angiotensin type-1 (AT1) receptor blockers. In the anemic group (13 patients), 3 patients received cotherapy with ACE inhibitors or receptor blockers. The [chi square] test revealed no difference in the occurrence of ACE inhibitor therapy between both groups (p = 0.813). Therefore, we conclude that the reported prevalence of anemia in COPD patients in our study is not influenced by an ACE inhibitor or AT1 receptor blocker medication. Overall, it is an interesting issue that should be taken into consideration for future studies.

REFERENCES

(1) John MS, Hoernig W, Doehner C, et al. Anemia and inflammation in chronic obstructive pulmonary disease. Chest 2005; 127:825-829

Matthias John, MD, PhD

University Hospital Charite

Berlin, Germany

Correspondence to: Matthias John, MD, PhD, Department of Pneumology, University Hospital Charite, Campus Mitte, Schumannstr. 20/21, 10098 Berlin, Germany; e-mail: matthias.john@charite.de

COPYRIGHT 2005 American College of Chest Physicians
COPYRIGHT 2005 Gale Group