A randomized placebo-controlled study of enalapril in the treatment of erythrocytosis after renal transplantation.
BACKGROUND
Erythrocytosis is a common complication of renal transplantation with an incidence of up to 17%. It is associated with an increased risk of complications due to thromboembolic events and has traditionally been treated by intermittent venesection. More recently, angiotensin-converting enzyme inhibitors have been shown to cause a fall in haematocrit in a number of groups of subjects and some uncontrolled studies have shown these drugs to be of possible therapeutic benefit in post renal transplant erythrocytosis.


METHODS
We performed a randomized double-blind placebo-controlled study in 25 patients with post-transplant erythrocytosis. Subjects received either 2.5 mg of enalapril daily or a placebo for 4 months and all patients completed the study period without any serious adverse effects.


RESULTS
Haematocrit fell from 52.7 (+/- SEM 0.7) to 47.1 (+/- 1.8) at 1 month and 46.1 (+/- 1.2) after 4 months in patients receiving enalapril, with no change in the placebo group (P = 0.004). We did not demonstrate any change in serum erythropoietin in either group.


CONCLUSIONS
Angiotensin-converting enzyme inhibitors are a safe and effective form of treatment for erythrocytosis developing after renal transplantation. The mechanism of action, however, is not mediated by changes in erythropoietin production and remains uncertain.
Beckingham
I J
IJ
Department of Surgery, University Hospital, Nottingham.
Woodrow
G
G
Hinwood
M
M
Rigg
K M
KM
Morgan
A G
AG
Burden
R P
RP
Broughton-Pipkin
F
F
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D004311:Double-Blind Method; D004656:Enalapril / Q000008:administration & dosage*; D004921:Erythropoietin / Q000097:blood*; D006400:Hematocrit; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D011086:Polycythemia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D012083:Renin / Q000097:blood
D000806:Angiotensin-Converting Enzyme Inhibitors; D004921:Erythropoietin; D004656:Enalapril; D012083:Renin