Ramipril in post-renal transplant erythrocytosis.
BACKGROUND
Posttransplant erythrocytosis (PTE; i.e., hematocrit [Ht] >=51%) may be responsible for cardiovascular events. Angiotensin-converting enzyme inhibitors (ACEIs) are increasingly employed in PTE treatment. Diverse ACEIs have been administered at variable doses and with erratic follow-up. In addition, guidelines recommend the administration of ACEIs as first-line therapy for PTE but do not give information on dosage. In this study the dose-response of a single ACEI was assessed, and patients were followed up for 1 year. The role of ACE gene polymorphism in both prevalence of PTE and successful response to ACEI therapy was also tested.


METHODS
At study entry, blood chemistry and ACE-gene polymorphism were measured. ACEI (ramipril) was initiated at 1.25 mg/day; if Ht was still >=51%, ramipril was increased every 6 weeks to ensuing greater dosages. Scheduled dosages were 1.25, 2.5, 5.0, 7.5 and 10 mg/day. Blood chemistry was repeated every 6 weeks. Serum erythropoietin (EPO) concentration was assayed at the start and end of the study. Follow-up was extended for 1 year.


RESULTS
PTE developed 12.6 +/- 16.0 months after transplantation in 40 out of 400 patients; 27 patients completed the study. Initial Ht was not correlated with any variable. Final Ht appeared normalized in 26 out of 27 patients. Mean dose (+/- SD) of ramipril was 4.6 +/- 3.6 mg. Mean time for correction of PTE was 135 days, and was not dependent on baseline Ht, hemoglobin or EPO. PTE relapsed in 4 patients. Prevalence of PTE and successful response to ramipril was not dependent on ACE-gene polymorphism.


CONCLUSIONS
Ramipril was effective in PTE; low doses normalized Ht in most patients. No clinical characteristics or biochemical variables predicted the response to ramipril. PTE may relapse; thus long-term follow-up is mandatory.
Esposito
Raffaela
R
Department of Nephrology, School of Medicine, University of Naples Federico II, Naples - Italy.
Giammarino
Anna
A
De Blasio
Antonietta
A
Martinelli
Vincenzo
V
Cirillo
Ferdinando
F
Scopacasa
Francesco
F
Federico
Stefano
S
Russo
Domenico
D
D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004921:Erythropoietin / Q000097:blood; D005260:Female; D006400:Hematocrit; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000502:physiology; D011086:Polycythemia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology*; D011110:Polymorphism, Genetic / Q000235:genetics; D015995:Prevalence; D011446:Prospective Studies; D017257:Ramipril / Q000627:therapeutic use*
D000806:Angiotensin-Converting Enzyme Inhibitors; D004921:Erythropoietin; D007703:Peptidyl-Dipeptidase A; D017257:Ramipril