Evolution of renal function in patients with severe intestinal failure on home parenteral nutrition

BACKGROUND

Kidney disease is a frequent but underestimated complication in patients suffering from intestinal failure (IF) treated by long-term home parenteral nutrition (HPN). The evolution in glomerular filtration rate (GFR) over time is poorly characterized. The current equations for estimating GFR have limited precision. No study has specifically investigated the reliability of recent creatinine-based estimated GFR (eGFR) equations in this population. The aim of this study was to evaluate the renal function decline under home parenteral nutrition (HPN) with a gold standard method and compare the performances of routinely used eGFR equations.

METHODS

Forty patients with HPN and two or more GFR measurements were retrospectively studied. The renal function decline was calculated by the slope drawn between the successive measured GFRs (mGFRs). The performances of the Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration, full age spectrum and revised Lund-Malmö equations were compared with reference methods (inulin or iohexol clearance).

RESULTS

The mean mGFR was 78 ± 28 mL/min/1.73 m2. The annual decline of mGFR was -1.9 mL/min/1.73 m2/year. No predisposing factor was identified to predict impairment in renal function. eGFR formulas grossly overestimated mGFR and had a low level of accuracy.

CONCLUSIONS

Patients with IF are at significant risk for impaired renal function. In this population, the tested eGFR equations were inaccurate. However, monitoring kidney function with mGFR remains important in these patients, as their GFR regularly declines and no specific risk factor has yet been identified.

Measurement of glomerular filtration rate in lung transplant recipients highlights a dramatic loss of renal function after transplantation

BACKGROUND

Chronic kidney disease (CKD) after lung transplantation (LT) is underestimated. The aim of the present study was to measure the loss of glomerular filtration rate (GFR) 1 year after LT and to identify the risk factors for developing Stage ≥3 CKD.

METHODS

LT patients in the University Hospital of Lyon had a pre- and post-transplantation measurement of their GFR (mGFR), and GFR was also estimated using the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

During the study period, 111 patients were lung transplant candidates, of which 91 had a pre-transplantation mGFR, and 29 had a mGFR at 1 year after LT. Six patients underwent maintenance haemodialysis after transplantation. Mean mGFR was 106 mL/min/1.73 m² before LT and 58 mL/min/1.73 m² 1 year after LT (P < 0.05) with a mean loss of 48 mL/min/1.73 m² per patient. The risk of developing Stage ≥3 CKD after LT was higher in patients with lower pre-LT mGFR (odds ratio for each 1 mL/min/1.73 m² increase: 0.94, 95% confidence interval 0.88-0.99). Receiver operator characteristics curves for the sensitivity and specificity of eGFR and mGFR for the prediction of CKD Stage ≥3 after LT found that pre-LT mGFR of 101 mL/min/1.73 m² and pre-LT eGFR of 124 mL/min/1.73 m² were the optimal thresholds for predicting Stage ≥3 CKD after LT.

CONCLUSION

The present study underlines the value of mGFR in the pre-LT stage and found major renal function loss after LT, and consequently two-thirds of patients have Stage ≥3 CKD at 1 year. All patients with a pre-LT mGFR <90 mL/min/1.73 m² warrant particular attention.

Cystic fibrosis-related diabetes before lung transplantation is associated with lower survival but does not affect long-term renal function

OBJECTIVE

To describe the prevalence of cystic fibrosis-related diabetes (CFRD) before and after lung transplantation (LT); to analyse the survival and renal function after LT according to the CFRD status before LT.

METHODS

Sixty cystic fibrosis (CF) patients transplanted at the Lyon University Hospital between 2004 and 2014 were included. Genotype, pancreatic status, age at LT, survival were recorded. Glucose tolerance status, daily insulin dose requirement, glomerular filtration rate (GFR), and daily glucocorticoid (GC) dose were recorded before LT and until December 2016.

RESULTS

The median follow-up was 5.6 (3.8-8.2) years, and nine patients died. Survival was poorest for patients with CFRD before LT compared with those without CFRD (P = 0.03) but was not correlated with the GFR before LT, with sex, age at LT, or CF genotype. The prevalence of CFRD was 68% at 2 years and 54% at 5 years. For persistent insulin-treated CFRD, the insulin requirement decreased (-2.1 IU/d/y; P < 0.01) and was correlated with the daily GC dose (+0.4 IU/d for one additional milligram, P = 0.012). Seven (11%) patients who had insulin-treated CFRD before LT became nondiabetic after LT, with a median time of 2 (1-4) years. After LT, the GFR decreased (-5.3 ml/min/1.73 m ² /y; P < 0.001) and was not correlated with the CFRD status before LT.

CONCLUSIONS

CFRD before LT is associated with poor survival after LT, which should lead to better management of diabetes. Some patients with pre-LT CFRD became nondiabetic after LT. CFRD is not associated with renal insufficiency after LT.

Acute and chronic non-pulmonary complications in adults with cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is a genetic disease that primarily affects the respiratory system and often leads to respiratory failure and premature death. Although pulmonary complications contribute to 85% of deaths, non-pulmonary complications are responsible for significant morbidity and mortality in adults with CF. Areas covered: This review summarizes acute and chronic non-pulmonary complications in CF patients, with emphasis on emerging complications and in the context of the current growth and aging of the CF adult population. It also addresses the potential benefits of CF transmembrane conductance regulator modulator therapy. Complications that occur after solid organ (e.g. lung and/or liver) transplantation have been excluded. The review is based on an extensive search of the available literature, using PubMed and international guidelines, and on the authors' clinical experience. Expert commentary: Acute non-pulmonary complications have been well described but should be recognized and managed carefully. Managing chronic non-pulmonary complications is an important and changing aspect of CF patient care, particularly with the emergence of novel complications in adults. Early detection of non-pulmonary complications is essential to the development of prevention and treatment strategies that aim to further improve the survival and health status of adult CF patients.

[Ageing with cystic fibrosis: Classical and emerging comorbidities in adults with cystic fibrosis]

Cystic fibrosis (CF) is a genetic disease with pulmonary involvement being predominant and often leading to respiratory failure and premature death. Non-pulmonary complications related to CF transmembrane conductance regulator (CFTR) defect are numerous and account for significant morbidity (exocrine pancreatic insufficiency, diabetes, CF-related liver disease, chronic sinusitis, osteoporosis). Improvement in patients' care led to a continuous increase in life expectancy, with a subsequent increase in the number of adult CF patients worldwide. Increased life expectancy comes with increased prevalence of CF-related comorbidities, but also with new emerging complications directly related to ageing (chronic kidney disease, cardiovascular risk factors, cancers). CFTR modulators might also contribute to modify the face of CF epidemiology and prognosis. Ageing with CF has become a challenge for CF patients and caregivers. This review summarizes classic and emerging comorbidities in the context of current growth and ageing of the CF population. It also addresses potential roles of CFTR modulators.