Changes to bone mineral density, the trabecular bone score and hip structural analysis following parathyroidectomy : a case report

Background: Reduction in bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) occurs in secondary hyperparathyroidism associated with chronic kidney disease. BMD generally increases following parathyroidectomy, however longitudinal changes to other DXA-derived parameters, the trabecular bone score (TBS) and hip structural analysis (HSA), have not been described. Postoperative calcium requirements and positive calcium balance raise concerns for an increased risk of vascular calcification. This case illustrates the dramatic increase in BMD that can follow parathyroidectomy in a patient on dialysis, and for the first time demonstrates improvements to HSA parameters and to the TBS. Case presentation: A 30-year old woman on haemodialysis underwent subtotal parathyroidectomy for secondary hyperparathyroidism. She developed a post-operative ‘hungry bone syndrome’ requiring substantial calcium and calcitriol supplementation. Six months post-parathyroidectomy, BMD increased by 42% at the lumbar spine, 30% at the femoral neck and 25% at the total proximal femur, with increases sustained over the following 18 months. The TBS increased by 8%. HSA showed a 63% increase in femoral neck cortical thickness and 38% reduction in the buckling ratio, consistent with increased femoral neck stability. The abdominal aortic vascular calcification score (0–24) increased from zero 8-years pre-parathyroidectomy to 2/24 at 18-months post-parathyroidectomy. Conclusion: BMD losses incurred by secondary hyperparathyroidism recover rapidly after parathyroidectomy, particularly at sites of trabecular bone. Bone architectural parameters, measured as the TBS and by HSA, also improve. Greater BMD gains may be associated with higher post-operative calcium requirements. While bone is the major reservoir for post-parathyroidectomy calcium supplementation, positive calcium balance may contribute to vascular calcification risk

Association between aortic calcification, cardiovascular events, and mortality in kidney and pancreas-kidney transplant recipients

BACKGROUND: Cardiovascular (CV) disease is the leading cause of death in kidney and simultaneous pancreas-kidney (SPK) transplant recipients. Assessing abdominal aortic calcification (AAC), using lateral spine x-rays and the Kaupilla 24-point AAC (0-24) score, may identify transplant recipients at higher CV risk. METHODS: Between the years 2000 and 2015, 413 kidney and 213 SPK first transplant recipients were scored for AAC at time of transplant and then followed for CV events (coronary heart, cerebrovascular, or peripheral vascular disease), graft-loss, and all-cause mortality. RESULTS: The mean age was 44 ± 12 years (SD) with 275 (44%) having AAC (26% moderate: 1-7 and 18% high: ≥8). After a median of 65 months (IQR 29-107 months), 46 recipients experienced CV events, 59 died, and 80 suffered graft loss. For each point increase in AAC, the unadjusted hazard ratios (HR) for CV events and mortality were 1.11 (95% CI 1.07-1.15) and 1.11 (1.08-1.15). These were similar after adjusting for age, gender, smoking, transplant type, dialysis vintage, and diabetes: aHR 1.07 (95% CI 1.02-1.12) and 1.09 (1.04-1.13). For recipients with high versus no AAC, the unadjusted and fully-adjusted HRs for CV events were 5.90 (2.90-12.02) and 3.51 (1.54-8.00), for deaths 5.39 (3.00-9.68) and 3.38 (1.71-6.70), and for graft loss 1.30 (0.75-2.28) and 1.94 (1.04-3.27) in age and smoking history-adjusted analyses. CONCLUSION: Kidney and SPK transplant recipients with high AAC have 3-fold higher CV and mortality risk and poorer graft outcomes than recipients without AAC. AAC scoring may be useful in assessing and targeted risk-lowering strategies

Health-related quality of life following kidney and simultaneous pancreas kidney transplantation

Introduction: Kidney and simultaneous pancreas kidney (SPK) transplant recipients are younger and fitter than most other dialysis patients, but are also more vulnerable in areas of social, emotional and physical interaction. Few studies have tracked their post-transplant health-related quality of life (HRQoL). Aim: To assess HRQoL following kidney and SPK transplantation, with comparison to dialysis patients, people with multiple co-morbidities and general population data. Methods: Patients completed the Kidney Disease Quality of Life Short Form (KDQOL-SF™) 1.3 to assess their pre-transplant HRQoL within 4 weeks of transplantation and 12 months later. Demographic and laboratory data were collected on participating patients and on non-participating patients at both time-points. Results: Of 118 patients who completed the baseline KDQOL-SF™, 75 (57 kidney and 18 SPK) completed the 1 year survey. Compared to baseline, 12 months HRQoL scores improved in all domains except for work status, exceeded those of patients on dialysis and, except for emotional wellbeing and mental health, exceeded the scores of people with multiple co-morbidities. For female transplant recipients, 12 months HRQoL scores were not statistically different from similarly aged women in the general population. Male transplant recipients had similar scores for bodily pain and energy/fatigue, but lower scores in other domains. Compared to kidney-only transplant recipients, SPK recipients achieved higher scores in work and sleep domains. Conclusion: Improvements in most HRQoL domains occur within 1 year of kidney or SPK transplantation, and women achieve similar HRQoL to women in the general population. These data are encouraging for patients contemplating transplant listing

Association between aortic calcification, cardiovascular events and mortality in kidney and pancreas-kidney transplant recipients

Background: Cardiovascular (CV) disease is the leading cause of death in kidney and simultaneous pancreas-kidney (SPK) transplant recipients. Assessing abdominal aortic calcification (AAC), using lateral spine x-rays and the Kaupilla 24-point AAC (0–24) score, may identify transplant recipients at higher CV risk. Methods: Between the years 2000 and 2015, 413 kidney and 213 SPK first transplant recipients were scored for AAC at time of transplant and then followed for CV events (coronary heart, cerebrovascular, or peripheral vascular disease), graft-loss, and all-cause mortality. Results: The mean age was 44 ± 12 years (SD) with 275 (44%) having AAC (26% moderate: 1–7 and 18% high: ≥8). After a median of 65 months (IQR 29–107 months), 46 recipients experienced CV events, 59 died, and 80 suffered graft loss. For each point increase in AAC, the unadjusted hazard ratios (HR) for CV events and mortality were 1.11 (95% CI 1.07–1.15) and 1.11 (1.08–1.15). These were similar after adjusting for age, gender, smoking, transplant type, dialysis vintage, and diabetes: aHR 1.07 (95% CI 1.02–1.12) and 1.09 (1.04–1.13). For recipients with high versus no AAC, the unadjusted and fully-adjusted HRs for CV events were 5.90 (2.90–12.02) and 3.51 (1.54–8.00), for deaths 5.39 (3.00–9.68) and 3.38 (1.71–6.70), and for graft loss 1.30 (0.75–2.28) and 1.94 (1.04–3.27) in age and smoking history-adjusted analyses. Conclusion: Kidney and SPK transplant recipients with high AAC have 3-fold higher CV and mortality risk and poorer graft outcomes than recipients without AAC. AAC scoring may be useful in assessing and targeted risk-lowering strategies

Aortic vascular calcification is inversely associated with the trabecular bone score in patients receiving dialysis

Introduction: Progressive chronic kidney disease (CKD) confers a marked increase in risk for vascular calcification, cardiovascular disease, fracture and mortality, with likely contributing factors including dysregulated bone metabolism and mineral homeostasis. In general population studies, increased vascular calcification is directly related to mortality and inversely related to bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA). In patients with CKD, abnormalities in turnover, mineralization and bone volume reduce the ability of DXA to predict fracture. The trabecular bone score (TBS) obtained from lumbar spine DXA images, provides a surrogate measure of microarchitectural integrity not captured by BMD. This study aimed to examine the association of the TBS to prevalent abdominal aortic calcification (AAC) in patients with CKD receiving dialysis. Methods: We performed a cross-sectional study of dialysis patients awaiting transplantation. All patients underwent laboratory testing, lateral spinal radiographs including the abdominal aorta, DXA imaging and TBS assessment. AAC scores were determined using the Kauppila method. Correlations and linear regression models were used to determine predictors of AAC scores. Results: 146 patients (60% male, mean age 48 ± 13 years) were included, of whom 49% had prevalent calcification with an AAC score ≥ 1. Of those with calcification, the mean AAC score was 7 ± 5.5 and 42 patients had scores ≥ 6, considered to indicate severe AAC. TBS values corresponding to intermediate or high risk for fracture (<1.31) were present in 35% of patients. TBS values correlated inversely to AAC scores (β = −0.206, p = 0.013) and remained significant in multivariable linear regression, adjusting for age, BMI and time on dialysis (−0.160, p = 0.031). There was no significant correlation of AAC scores to any BMD parameter. Conclusion: There is a high prevalence of AAC in relatively young dialysis patients awaiting transplantation and their AAC scores are inversely related to the TBS but not to DXA-derived BMD parameters. In patients with CKD on dialysis, TBS assessment reflects microarchitectural abnormalities of bone not captured by DXA. The inverse relationship of TBS to vascular calcification may provide insights into bone-vascular interactions in CKD

Cryoglobulinemic Glomerulonephritis Associated With Nodal and Renal Infiltration by T-Cell Lymphoma of T-Follicular Helper Phenotype: A Case Report

We present a unique case of cryoglobulinemic glomerulonephritis associated with nodal and renal infiltration by T-cell lymphoma of T-follicular helper phenotype. The patient presented with transient neurologic symptoms, severe nephritic syndrome with nephrotic-range proteinuria, and acute kidney injury. He had elevated double-stranded DNA levels, low complement levels, detectable cryoglobulin, and detectable immunoglobulin M (IgM) paraprotein. The kidney biopsy showed cryoglobulinemic glomerulonephritis with a membranoproliferative pattern and diffuse interstitial infiltrates on light microscopy; IgM, C3 but weak IgG, C1q, and negative C4d staining on immunofluorescence; and deposits with organized substructures on electron microscopy. Positron emission tomography showed diffuse uptake in bilaterally enlarged kidneys and a localized group of lymph nodes. Subsequent lymph node biopsy revealed Epstein-Barr virus–negative nodal T-cell lymphoma, which was also proven in renal tissue. The association between T-cell lymphoma, autoantibodies, and cryoglobulinemia may represent a paraneoplastic phenomenon. His renal prognosis has been excellent, but overall prognosis and survival is dictated by the clinical course of T-cell lymphoma

Adenine Phosphoribosyltransferase Deficiency : a potentially reversible cause of CKD

Adenine phosphoribosyltransferase (APRT) enzyme deficiency is an important and potentially reversible cause of progressive chronic kidney disease. It is a rare, autosomal recessive disorder that was first described in 19741 with more than 40 known mutations2, 3 and estimated prevalence of 1 in 50,000 to 100,000 persons.2, 4, 5 The APRT enzyme is important for the conversion of adenine to adenosine monophosphate in the salvage purine pathway. Deficiency of this enzyme results in the metabolism of adenine into 2,8-dihydroxyadenine (DHA) by xanthine oxidase (xanthine dehydrogenase) (Figure 1a). DHA is highly insoluble in urine and will precipitate to cause either urolithiasis or crystal nephropathy. There are no known extrarenal manifestations and reasons for this remains unclear given the extensive tissue distribution of this enzyme