Erythropoietin deficiency and relative resistance cause anaemia in post-renal transplant recipients with normal renal function

BACKGROUND: Following successful renal transplantation, blood erythropoietin(Epo) levels peak in two phases during the first 2–3 months,and blood haemoglobin/haematocrit (Hb/Hct) levels are restoredto normal in a period of 2–6 months. However, some transplantrecipients continue to remain anaemic in spite of normal graftfunction and in the absence of recognizable causes. The roleof endogenous Epo production in the causation of anaemia insuch patients is poorly understood and has been investigatedin this study. METHODS: Twenty-three post-renal transplant recipients with stable normalrenal function were studied. Eleven of these patients had normalHb/Hct levels (group 1) and served as control for the rest 12patients with anaemia (group 2). Patients included in group2 had no readily recognizable cause for their anaemia. Otherlaboratory and clinical findings were similar in both groups.Patients with erythrocytosis were excluded. Serum Epo levelswere measured in all patients. Five patients in group 2 weretreated with recombinant human erythropoietin (rHuEpo) and theirerythropoietic response was assessed. rHuEpo was discontinuedwhen the target Hb/Hct levels (lowest normal range) were achievedand the patients were followed up for a further period of 9–12months. RESULTS: Five patients in group 1 had normal expected serum Epo levelswhereas the other six patients had inappropriately high serumEpo levels with respect to their Hb/Hct status suggestive ofrelative ‘Epo resistance’. Serum Epo levels in allpatients except two in group 2 were low indicative of ‘Epodeficiency’. The two exceptional patients in group 2 hadhigher serum Epo levels in the presence of anaemia suggestiveof relative ‘Epo resistance’. All five patients treated with rHuEpo responded adequately byachieving normal Hb/Hct levels. Three of them were originally‘Epo deficient’ and they reached target Hb/Hct levelsin a mean period of 4 weeks, requiring a mean cumulative rHuEpodose of 428.3 units/kg. The other two patients with higher initialserum Epo levels, and considered to be ‘Epo resistant’,required an average of 11 weeks of treatment and a mean cumulativerHuEpo dose of 1582.5 units/ kg, indicating an increased Epodemand. On cessation of therapy the Hb/Hct levels fell in allfive patients to pretreatment values in 6 months. CONCLUSIONS: There are important variations in the endogenous Epo productionin renal transplant patients with normal renal function, thecause of which is not clear. Epo deficiency and relative Eporesistance play a causative role for anaemia in some post-renaltransplant recipients with stable normal renal function. Theyrespond adequately to rHuEpo administration.     

Posttransplantation Calcineurin Inhibitor-Induced Hemolytic Uremic Syndrome: Single-Center Experience

Introduction

Calcineurin inhibitor (CNI) induced HUS, although rare, can be a serious complication of renal transplantation. Classical syndrome of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury may not be fully manifested.

Methods

We retrospectively analyzed our data in 950 kidney recipients under follow-up in our center (1994 - 2008). We reviewed the kidney biopsies performed for these patients to exclude conflicting diagnoses like antibody mediated rejection.

Results

HUS was diagnosed in 12 patients (1.26%). None of them had HUS as the original kidney disease. Cyclosporine was the primary immunosuppression in 9 and tacrolimus in 3 patients. The median day of onset was 7 days. Manifestations were anemia (100%), thrombocytopenia (75%), elevated reticulocyte count (62.5%), fragmented red blood cells (8.3%), elevated lactate dehydrogenase (LDH) enzyme (83.3%), increased fibrin degradation product (FDP) (83.3%), reduced haptoglobin level (42.9%) and hyperbilirubinemia (25%). CNI elimination was the first step in the management. Transfusion of fresh frozen plasma (FFP) was used in 10 patients and plasma exchange with FFP in the other two. All grafts recovered function. Cyclosporine or tacrolimus were reintroduction in two patients after complete clinical and laboratory recovery. Both patients developed recurrence of HUS. While the former did not the latter did recover on further treatment of HUS.

Conclusion

Anemia, thrombocytopenia, elevated LDH and FDP are the most frequent manifestations of HUS. Early CNI elimination and fresh plasma transfusion can revert CNI induced HUS and save the graft. Reintroduction of CNI may be deleterious to the graft and should be avoided.     

Low Levels of Th1-Type Cytokines and Increased Levels of Th2-Type Cytokines in Kidney Transplant Recipients With Active Cytomegalovirus Infection

Background

Cytomegalovirus (CMV) infection is a major complication after kidney transplantation. It is clear that Th1 and Th2 cell subsets are of major importance in determining the class of immunoprotective function in infectious diseases. Given the strong influence exerted by Th1- and Th2-type immunity on the outcome of infections, we felt it important to elucidate the levels of Th1- and Th2-type cytokines to CMV-related antigens in kidney recipients and to identify antigens that play an essential role in preventing the development of CMV infection and/or disease.

Methods

One hundred twenty subjects were followed for CMV infection by the antigenemia assay. We investigated peripheral blood mononuclear cells (PBMCs) responses to five CMV-related peptide antigens (pp65, gB, pp150, pp28, and pp38). Stimulation index was determined by radioactive thymidine uptake, while the production of Th1-type cytokines (interferon-γ and tumor necrosis factor-α) and Th2-type cytokines (interleukins-4 and -10) were measured by enzyme-linked immunosorbent assay.

Results

The levels of Th1-type cytokine production after stimulating PBMCs with CMV-related antigens gB and pp150 resulted in significant decreases in the levels of interferon-γ, while pp65, pp150, and pp38 produced significant decreases in the level of tumor necrosis factor-α between the two groups (P < .05). For Th2-type cytokines only pp28 produced a significant increase in the level of interleukin-10 between the two groups (P < .05). Regarding the Th1:Th2 ratios, a lower Th1-bias was observed among the CMV-positive patients for PBMCs stimulated with three CMV-related antigens (pp65, pp38, and pp28).

Conclusion

Low levels of Th1-type cytokines and increased levels of Th2-type cytokines upon stimulation with CMV-related peptide antigens were associated with reduced cell-mediated immunity to CMV, thus seeming to correlate with active CMV infections.     

Active Management of Post-Renal Transplantation BK Virus Nephropathy: Preliminary Report

Objective

To assess the efficacy of leflunomide, intravenous immunoglobulins, and ciprofloxacin as active treatment of postrenal transplant BK virus nephropathy (BKVN) in graft outcome at 1 year.

Patients and Methods

Renal transplant recipients with positive results of 2 BK virus polymerase chain reaction tests of urine and blood underwent graft biopsy to confirm BKVN. If BKVN was diagnosed, antimetabolite therapy (mycophenolate mofetil or azathioprine) was changed to leflunomide therapy accompanied by a course of immunoglobulin and oral ciproflxacin.

Results

Of 18 patients evaluated, 72% were men. Nine patients received cadaveric organs, with a mean of 3.6 HLA mismatches. All patients received induction thereapy (61% thymoglobulin), and 61% received antirejection therapy before BKVN was diagnosed. Maintenance immunosuppression therapy was primarily with prednisolone (94%); mycophenolate mofetil, 2 g/d (94%); and tacrolimus (61%). At baseline, mean (SD) creatinine clearance was 35.6 (11.5) mL/min/1.73², which decreased to 29.3 (17.3) mL/min/1.73² at 1 year (P = .01). Patients were divided into 2 groups of 9 each according to creatinine clearance values. In group 1, baseline value was 44.5 (6.6) mL/min/1.73², compared with 25.36 (7.8) mL/min/1.73² in group 2, which decreased to 42.66 (12.8) mL/min/1.73² (P = .23) and 16.76 (9.0) mL/min/1.73² (P = .009), respectively, at 1 year. Three grafts (16.7%) were lost by the end of the study, all in group 2 (P = .03).

Conclusion

Late diagnosis and intensive immunosuppression predispose to BKVN. Early active treatment of BKVN may improve graft outcome at 1 year posttransplantation.     

Lymphedema: an unusual complication of sirolimus therapy

INTRODUCTION: Lymphedema is an increasingly observed complication of sirolimus (SIR) therapy. In this report, we describe four renal recipients with SIR-induced lymphedema of varying severity. CASES REPORTS: Patient 1, a 38-year-old man developed lymphedema of the left upper limb after being exposed to SIR for 30 months (mean daily Rapamune dose, 3 mg; trough level, 10-18 ng/mL). Venography and duplex ultrasound were normal. Lymphangiography was showed delayed lymphatic drainage. SIR was replaced with Prograf with significant improvement in the lymphedema over the next 6 months. Patient 2, a 26-year-old woman, developed lymphedema of the left lower limb at 24 months after starting SIR (mean daily dose, 3 mg; trough level, 10-15 ng/mL). Lymphangiography showed delayed drainage of lymphatics in the left lower limb. The patient was shifted to Prograf and there was some improvement over the next 4 months. Patient 3, a 28-year-old man, developed lymphedema of the left upper limb at 24 months after the start of SIR (mean daily dose, 2 mg, trough level, 6-15 ng/mL). Lymphangiography showed evidence of lymphatic obstruction. SIR was changed to cyclosporine with only mild improvement in lymphedema over the next 6 months. Patient 4, a 46-year-old man, developed lymphedema of the right upper limb at 7 months after starting SIR (mean daily dose, 6 mg; trough level, 10-16 ng/mL). Lymphangiography showed complete blockage of the lymphatic channels. SIR was changed to cyclosporine and there was mild improvement in lymphedema over the next 8 to 10 months. CONCLUSION: The exact mechanism of SIR-induced lymphedema is unknown. The absence of other demonstrable etiologies and spontaneous improvement after discontinuation of SIR suggest that this drug was the responsible factor in these four patients. It occurred 7 to 30 months after transplantation. This is the fourth such report in the literature to the best of our knowledge.     

De novo Crohn's disease in a renal transplant recipient

The prevalence of inflammatory bowel disease (IBD) after renal transplantation is affected by the immune tolerance and the modality of immunosuppression. Mycophenolate mofetil (MMF) may have a promoting effect on the development of posttransplantation erosive enterocolitis and a Crohn's disease-like pattern of colitis. We have presented a 40-year-old man with end-stage renal disease due to chronic glomerulonephritis who commenced hemodialysis for 2 months before receipt of a live unrelated renal transplant. He developed early posttransplantation diabetes mellitus and an anti graft rejection episode, which responded to a methylprednisolone pulse and OKT3 treatment. His immunosuppressive regimen included prednisolone, MMF, and tacrolimus. Three years after transplantation, he developed mild constitutional symptoms, mouth ulcerations, and chronic intermittent bloody diarrhea. Colonoscopy showed active segmental colitis with aphthous ulcers, involving the proximal descending colon and the splenic flexure. Colonic biopsies showed distended and branched crypts in the ascending colon, moderate active chronic colitis with regenerative atypia, skipping appearance, and ulceration in the splenic flexure and descending colon. The edematous crypts were associated with ulcerations in the sigmoid colon and rectum. The features were highly suggestive of Crohn's disease. He was successfully treated with high-dose steroids and 5-aminosalicylic acid. Subsequently, he developed chronic transplant glomerulopathy and restarted hemodialysis. We concluded that de novo Crohn's disease may develop in renal transplant recipients despite immunosuppressive therapy especially with MMF immunosuppression.     

Early Sirolimus Therapy in Renal Transplant Recipients at High Risk: Is It Justified?

Background

We studied early sirolimus (SRL) therapy in renal transplant recipients at high risk after administration of antithymocyte globulin or interleukin-2 receptor blockade induction.

Patients and Methods

In 45 patients, SRL therapy was started within 1 month after transplantation. The primary indications for conversion of treatment from calcineurin inhibitors (CNIs)-mycophenolate mofetil (MMF)-steroid to SRL-MMF-steroid were biopsy-proved rejection (after treatment), CNI toxicity, CNI elimination, and acute tubular necrosis. Pediatric, geriatric, and other patients with medical comorbidities were not excluded.

Results

Post-SRL rejection episodes were reported in 22.2% of recipients including 15.6% who were resistant to steroid therapy. Mean (SD) follow-up after SRL therapy was 59.9 (8.1) months. Proteinuria greater than 2 g/d (P = .001), leukopenia (P < .001), hyperlipidemia (P < .001), and transaminases values (P = .02) increased significantly after SRL therapy. Graft survival was 88.8%, and patient survival was 93.3%. There was significant improvement in serum creatinine concentration and estimated creatinine clearance by the end of the study (P < .001). A high incidence of adverse effects and infections was noted post-SRL therapy, and the drug was discontinued in 31% of patients because of multiple adverse effects. At multivariate analysis, age, hypertension, nutritional status, bone marrow suppression, hyperlipidemia, and graft dysfunction were identified as risk factors for worse graft and patient outcome.

Conclusion

Early treatment with combined SRL-MMF-steroid may be effective as a CNI-free immunosuppression regimen in patients at high risk; however, there is a high rate of adverse effects during long-term follow-up.