Christian Noel

Subtotal parathyroidectomy with thymectomy for autonomous hyperparathyroidism after renal transplantation

There is currently no consensus on the operation that should be performed in patients with tertiary hyperparathyroidism (HPT) after renal transplantation.

Three-year outcome of isolated glomerulitis on 3-month protocol biopsies of donor HLA antibody negative patients.

Transplant glomerulitis (TG) can lead to the diagnosis of acute humoral rejection when associated with C4d. Recent data have shown that, in patients with donor‐specific antibodies, TG is a sign of humoral rejection, even in the absence of C4d. However, the clinical significance of isolated TG, i.e. TG without C4d deposition or morphological evidence of rejection, has not been specifically studied in protocol biopsies of recipients without donor‐specific antibodies. We compared 20 isolated TG‐patients with 44 selected recipients without TG or any rejection‐associated change. The two groups had similar baseline characteristics. After a 3 year follow‐up, renal function, acute rejection rate, and development of HLA antibodies were not significantly different between the two groups. Isolated TG had no deleterious consequences on the 3 year graft outcome. Eleven patients of the glomerulitis‐group had another allograft biopsy during follow‐up: glomerular lesions returned to normal in six patients whereas the persistence of glomerulitis or features consistent with chronic transplant glomerulopathy were noticed in the remaining five patients. Four of these five patients had pretransplant non‐donor specific HLA antibodies. In conclusion, although isolated TG had no impact on allograft function at 3 year, histological outcome could be related to patient sensitization.

Osteomalacia induced by vitamin D deficiency in hemodialysis patients: the crucial role of vitamin D correction

Vitamin D deficiency/insufficiency is significantly prevalent in chronic kidney disease. Data in the literature are however scarce about the effects of this deficiency on bone metabolism in hemodialysis (HD) patients. Moreover, it is still debated whether low vitamin D levels should be normalized in HD patients. In this paper, we report two cases showing the deleterious consequences of vitamin D deficiency in HD patients which is characterised by hypophosphatemia, hypocalcemia and osteomalacia (OM) leading to bone fractures. As vitamin D repletion is an easy way to treat OM, this report underlines the importance of monitoring and correction of vitamin D deficiency in this population.

Purity of islet preparations and 5-year metabolic outcome of allogenic islet transplantation

In allogenic islet transplantation (IT), high purity of islet preparations and low contamination by nonislet cells are generally favored. The aim of the present study was to analyze the relation between the purity of transplanted preparations and graft function during 5 years post‐IT. Twenty‐four patients with type 1 diabetes, followed for 5 years after IT, were enrolled. Metabolic parameters and daily insulin requirements were compared between patients who received islet preparations with a mean purity <50% (LOW purity) or ≥50% (HIGH purity). We also analyzed blood levels of carbohydrate antigen 19‐9 (CA 19‐9)—a biomarker of pancreatic ductal cells—and glucagon, before and after IT. At 5 years, mean hemoglobin A1c (HbA1c levels) (P = .01) and daily insulin requirements (P = .03) were lower in the LOW purity group. Insulin independence was more frequent in the LOW purity group (P < .05). CA19‐9 and glucagon levels increased post‐IT (P < .0001) and were inversely correlated with the degree of purity. Overall, our results suggest that nonislet cells have a beneficial effect on long‐term islet graft function, possibly through ductal‐to‐endocrine cell differentiation. ClinicalTrial.gov NCT00446264 and NCT01123187.

Factors associated with the variability of calcineurin inhibitor blood levels in kidney recipients grafted for more than 1 year

The study of calcineurin inhibitor (CNI) blood level variability to evaluate adherence in transplantation has improved over the years. The aim of our study was to assess factors associated with this variability using the coefficient of variation (CV). A cross‐sectional sample of kidney recipients grafted for more than 1 year was recruited. We recorded clinical data, data from a clinical pharmacist interview and from six questionnaires measuring adherence, satisfaction, behaviours, beliefs, perception of the illness and social vulnerability. A total of 408 recipients were enrolled (61.2% male, mean age 54) and divided into two groups: low variability CV < 30% (n = 302), high variability CV ≥ 30% (n = 106). In univariate analysis, hospital‐home distance, cyclosporine, time since transplantation and presence of discrepancies in drug regimen were associated with a greater risk of CV ≥ 30%. In contrast, tacrolimus QD conferred a lower risk of CV ≥ 30%. In multivariate analysis, only the presence of discrepancies remained significant: (OR 3.2 [1.21–9.01]; P = 0.022). Discrepancies in drug regimen appear as the main risk factor associated with CNI blood variability. The clinical pharmacists input is an accurate and simple way of detecting non‐adherence which is not revealed in self‐report questionnaires.

Giant osteoclasts in patients under bisphosphonates

BackgroundBisphosphonates have been widely used for treatment of high bone resorption states. It lowers bone turnover by inhibiting osteoclasts bone resorption with various mechanisms of actions: inhibition of osteoclast formation and attachment to the bone surface, induction of metabolic injury, alteration of vesicle trafficking and induction of osteoclast apoptosis. Bone biopsies studies from patients under bisphosphonates have shown that some resorption parameters are decreased as expected but the number of osteoclasts seems not to be necessarily decreased. The description of osteoclasts morphology from patients treated with bisphosphonates has rarely been reported in the literature.Case presentationWe describe in this paper two patients treated with bisphosphonates from whom iliac crest bone biopsies have shown large, multinucleated and apoptotic osteoclasts that were not associated with bone resorption activities. The characteristics of these osteoclasts are described and the literature reviewed.ConclusionThe appropriate recognition of these giant osteoclasts in bone tissues from patients treated with bisphosphonates is of primary importance for bone pathologists and should not be interpreted as signs of increased bone resorption as seen in hyperparathyroidism, bone cancer or Paget’s disease of bone.