Theophylline modulates erythrocytosis after renal transplantation

Risk factors and outcomes of post-transplant erythrocytosis among adult kidney transplant recipients: a systematic review and meta-analysis

Post-transplant erythrocytosis (PTE) can occur in up to 10-16% after kidney transplant (KT). However, the post-transplant outcomes of recipients with PTE in the literature were conflicting. We performed systematic review and meta-analysis of published studies to evaluate risk factors of PTE as well as outcomes of recipients who developed PTE compared with controls. A literature search was conducted evaluating all literature from existence through February 2, 2021, using MEDLINE and EMBASE. Data from each study were combined using the random-effects model. (PROSPERO: CRD42021230377). Thirty-nine studies from July 1982 to January 2021 were included (7,099 KT recipients). The following factors were associated with PTE development: male gender (pooled RR = 1.62 [1.38, 1.91], I²  = 39%), deceased-donor KT (pooled RR = 1.18 [1.03, 1.35], I²  = 32%), history of smoking (pooled RR = 1.36 [1.11, 1.67], I²  = 13%), underlying polycystic kidney disease (PKD) (pooled RR=1.56 [1.21, 2.01], I² =44%), and pretransplant dialysis (pooled RR=1.6 [1.02, 2.51], I² =46%). However, PTE was not associated with outcomes of interest, including overall mortality, death-censored graft failure, and thromboembolism. Our meta-analysis demonstrates that male gender, deceased-donor KT, history of smoking, underlying PKD, and pretransplant dialysis were significantly associated with developing PTE. However, with proper management, PTE has no impact on prognosis of KT patients.

Post-transplant erythrocytosis after kidney transplantation: A review

Post-transplant erythrocytosis (PTE) is defined as persistently elevated hemoglobin > 17 g/dL or hematocrit levels > 51% following kidney transplantation, independent of duration. It is a relatively common complication within 8 months to 24 months post-transplantation, occurring in 8%-15% of kidney transplant recipients. Established PTE risk factors include male gender, normal hemoglobin/hematocrit pre-transplant (suggestive of robust native kidney erythropoietin production), renal artery stenosis, patients with a well-functioning graft, and dialysis before transplantation. Many factors play a role in the development of PTE, however, underlying endogenous erythropoietin secretion pre-and post-transplant is significant. Other contributory factors include the renin-angiotensin- aldosterone system, insulin-like growth factors, endogenous androgens, and local renal hypoxia. Most patients with PTE experience mild symptoms like malaise, headache, fatigue, and dizziness. While prior investigations showed an increased risk of thromboembolic events, more recent evidence tells a different story-that PTE perhaps has lessened risk of thromboembolic events or negative graft outcomes than previously thought. In the evaluation of PTE, it is important to exclude other causes of erythrocytosis including malignancy before treatment. Angiotensin converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) are the mainstays of treatment. Increased ACE-I/ARB use has likely contributed to the falling incidence of erythrocytosis. In this review article, we summarize the current literature in the field of post-transplant erythrocytosis after kidney transplantation.

[The erythrocytosis after renal transplantation: a retrospective study about 11 recipients ]

Introduction

L’érythrocytose après transplantation rénale (ETR) survient chez 5 à 20 % des transplantés rénaux. Le but de notre travail est de déterminer la prévalence de l’érythrocytose chez les transplantés rénaux et de connaître les facteurs de risque d’apparition de cette érythrocytose et son impact sur la fonction rénale.

Méthodes

Notre étude est rétrospective portant sur 74 transplantés rénaux. Nous avons distingué 2 groupes de patients selon la présence ou non de l’érythrocytose, celle-ci étant définie par un taux d’hématocrite supérieur à 51% selon les recommandations de Kidney Disease Improving Global Outcomes (KDIGO).

Résultats

L’érythrocytose est retrouvée chez 11 patients, soit une prévalence estimée à 14,8%. On note une nette prédominance masculine (63,6% vs 36,4%). L’âge moyen de nos patients était de 40 ± 11 ans pour le Groupe1 vs 36 ± 13 ans pour le Groupe 2. La durée de transplantation rénale était de 42 ± 33 mois pour le groupe1 vs 36±26 mois pour le groupe2. Le délai d’apparition de l’érythrocytose par rapport à la transplantation rénale est de 9±7 mois. Aucun facteur de risque n’a été retrouvé dans notre série. Quatre patients ont nécessité des saignées et 9 ont été traités par un inhibiteur de l’enzyme de conversion. La rémission a été notée chez tous les patients. On n’a pas noté de complication thrombo-embolique.

Conclusion

L’érythrocytose après transplantation rénale reste une complication, le plus souvent, bénigne. Le traitement est basé sur les saignées mais surtout les inhibiteurs de l’enzyme de conversion.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Recommendations for Outpatient Monitoring of Kidney Transplant Recipients

Clinical and laboratory outpatient monitoring is an important tool in the prevention and management of complications associated with kidney transplantation and immunosuppressive therapy. In the absence of standard protocols for outpatient surveillance of kidney transplant recipients, recommendations for frequency and type of monitoring are determined by the likelihood of problems that are unique to the individual transplant recipient and the particular posttransplantation period. In addition, it is imperative to maintain the transplant recipient's overall health by screening for conditions or diseases that can be linked to prior renal disease, immunosuppressive therapies, and general health maintenance.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Theophylline: recent advances in the understanding of its mode of action and uses in clinical practice

Theophylline, a drug that has been used for several decades, has several different actions at a cellular level, including inhibition of phosphodiesterase isoenzymes, antagonism of adenosine, enhancement of catecholamine secretion, and modulation of calcium fluxes. Recently, theophylline was found to have several immunomodulatory and anti-inflammatory properties, and thus interest in its use in patients with asthma has been renewed. The use of theophylline in the treatment of asthma and chronic obstructive pulmonary disease has diminished with the advent of new medications, but theophylline remains beneficial, especially in the patient with difficult refractory symptoms. In the future, theophylline may be used as treatment for bradyarrhythmias after cardiac transplantation, prophylactic medication to reduce the severity of nephropathy associated with intravenous administration of contrast material, therapy for breathing problems during sleep, and treatment for leukemias.