RESUMO
BACKGROUND AND OBJECTIVE: A clinician was intrigued about HbA1c upper 9% (75 mmol/mol) in a 76 year-old women with normal glycemia. Further explorations were performed in order to understand this discordance. METHODS: First HbA1c test was performed on a HLC -723 G11 apparatus (Tosoh Bioscience) and thereafter compared to the HLC-723-G8 (Tosoh Bioscience), the Capillaris 3 Tera (Sebia) and the DCA Vantage point of care testing (POCT) (Siemens) apparatus. In addition, study of Hemoglobin (Hb) fraction and mutation analysis of HBB gene was realized due to the suspicion of an Hb variant. RESULTS: Twice high results of HbA1c (9.3%, 78 mmol/mol and 10%, 86 mmol/mol) on the HLC-723 G11 was not confirmed with other instruments. HbA1c result for the same sample was 5.2% (33 mmol/mol) for the HLC-723 G8, 5.3% (34 mmol/mol) for the Capillaris and 6.2% (44 mmol/mol) for the DCA Vantage POCT. The subject had normal glycemia and none signs of diabetes mellitus. An abnormal Hb fraction was visualized on the graphs for the HLC-723 G11 and Capillaris but not for the HLC-723 G8 analyzer. Study of Hb fraction confirmed the presence of an abnormal Hb fraction that was identifed as an Hb G-Copenhagen through mutation analysis of HBB gene. CONCLUSION: This case evidenced an interference on HbA1c test in presence of Hb G-Copenhagen depending to the analyzer used. This report help to alert of such possibility and to remain that a discordance between HbA1c and glycemia can be due to an Hb variant.
RESUMO
BACKGROUND: Glomerular filtration rate (GFR) decline ≥30% over 2 years can substitute for the conventional 'doubling of serum creatinine' to predict end-stage renal disease in patients with native kidneys. While chronic kidney disease trajectory is less predictable in transplanted patients, recent data have suggested that similar GFR decline might be an acceptable surrogate for long-term transplant outcome. We sought (i) to confirm the prognostic value of an early GFR decline in kidney transplant recipients and (ii) to determine whether using direct measurement of GFR with inulin improves the performance of this surrogate. METHODS: We retrospectively analysed all recipients transplanted between 1989 and 2000 in our centre, with inulin-measured and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)-estimated GFR at 1 and 5 years post-transplant, and evaluated the performance [time-dependent area under the receiver operating characteristic curve (ROC AUC) and subdistribution hazard ratio (sdHR) with competing risk model] of GFR change to predict graft failure and all-cause mortality. RESULTS: Out of 417 kidney transplant recipients, 116 patients had lost their graft and 77 had died 16 years after transplantation. While being significantly associated with graft failure [sdHR = 2.37 (95% confidence interval 1.47-3.83)], CKD-EPI-GFR decline ≥30% failed to appropriately predict long-term graft survival (C-statistics of 0.63). Concordance between inulin-GFR and CKD-EPI-GFR to detect similar GFR change was only 53%. Inulin-GFR change was, however, not a better predictor (C-statistics of 0.59). Comparable results were observed for mortality. CONCLUSIONS: Our data suggest that early GFR decline is a poor surrogate for long-term transplant outcome, even when change in GFR is directly measured by a reference method.
RESUMO
BACKGROUND: The slopes of estimated glomerular filtration rate (eGFR) equations are used in the longitudinal follow-up of transplant patients. A 30% reduction in eGFR over 2 years is often used to predict the subsequent risk of mortality or end-stage renal disease. Whether, at the individual level, such changes in eGFR correspond to changes in measured GFR (mGFR) is actually unknown. METHODS: The performance of serum creatinine-based eGFR equations was compared with mGFR during the longitudinal follow-up of 20 years in a monocentric study of 417 transplanted patients. RESULTS: The accuracy within 30% for the eGFR equations varied between 70 and 75%. All eGFR equations showed a similar pattern, very like the mGFR time profiles. Individual changes (slopes) of mGFR or eGFR were predictive of graft loss in the next months or years, following the decline in GFR, with no evidence for a difference. However, although the tendency is the same as for mGFR, the percentage of transplant patients with a >30% GFR decrease in the last period before graft loss is significantly lower for eGFR than for mGFR, with discordant results from mGFR in ~25% of the cases. CONCLUSIONS: All eGFR equations showed similar trends as mGFR, but eGFR predictions may not be very useful at the individual patient level.
