Anemia: A Continuing Problem Following Kidney Transplantation

Abstract

Cardiovascular disease is a leading cause of death among kidney transplant recipients. Anemia, a risk factor for cardiovascular complications among patients with chronic kidney disease, has not been well characterized in kidney transplant recipients. We performed a retrospective cohort study of the prevalence of and factors associated with anemia among 240 patients who underwent kidney transplantation at our institution. The mean hematocrit (Hct) rose from 33% at 1 month after transplantation to 40% at 12 months after transplantation. The proportion of patients with Hct < 36% was 76% at transplantation and 21% and 36%, 1 year and 4 years after transplantation, respectively. Six months after transplantation, women had higher likelihood (OR = = 3.61) of Hct < 36%, while higher Hct at 3 months (OR = = 0.67 for 1% higher Hct) and diabetes (OR = = 0.14) were associated with a lower likelihood of Hct < 36%. Similar associations were seen 12 months after transplantation. Even among patients with Hct < 30%, only 36% had iron studies, 46% received iron supplementation and 40% received recombinant human erythropoietin. Awareness of factors associated with a lower Hct may prompt better anemia screening and management, potentially improving cardiovascular outcomes among kidney transplant recipients.

Posttransplantation Anemia

“…Immediately after transplantation, surgical blood loss, induction immunosuppression, frequent phlebotomy, and allograft dysfunction causing a persistent uremic state contribute to continued anemia (15). In patients with well-functioning allografts, anemia usually resolves by 3 to 6 months after transplantation (16). However, some patients have persistent anemia, and late PTA, defined as anemia occurring Ն6 to 12 months after transplantation, is common and understudied (11).…”

“…Mix et al (16) studied 240 kidney transplant recipients who were followed at an academic medical center in Boston and reported that 76% of patients had hematocrit Ͻ36% at the time of transplantation and 21% and 36% at 1 and 4 years after transplantation, respectively. Another study with 128 patients, using the WHO/ AST definition of anemia, reported the incidence of anemia as 26% at 5 years after transplantation (11).…”

“…However, delayed graft function or chronic allograft dysfunction may cause damage or dysregulation of EPO-producing peritubular interstitial In the setting of rapid erythropoiesis early after transplantation (15), functional or absolute iron deficiency inevitably occurs, especially when there is also surgical blood loss and residual uremic milieu. Observational studies indicated that iron status is often not included in the assessment of PTA (12,16). In addition, an accurate assessment of iron deficiency is limited by the currently used assays, which are often unreliable in the posttransplantation setting.…”

“…Prophylactic antimicrobial agents, including ganciclovir, valganciclovir, dapsone, and trimethoprim-sulfamethoxazole, can cause myelosuppression and anemia. Glucose 6-phosphate dehydrogenase is an essential enzyme for normal RBC life span and oxidizing processes, and in its absence, dapsone and, less commonly, trimethoprim-sulfamethoxazole, can lead to sudden destruction of RBCs and hemolytic anemia (16,34). Ganciclovir and valganciclovir induce bone marrow suppression in 8% to 25% of solid-organ transplant patients (35).…”

“…Recipients of kidneys from older donors (especially older than 60 years), older recipients, and women, possibly secondary to iron deficiency from menses and androgen deficiency, were more likely to have anemia (12,16). Despite the trend toward both older donors and recipients in the past decade, a recent European study showed that the prevalence of anemia has remained unchanged (17).…”