Falsely elevated parathyroid hormone in a patient with osteoporosis: a case report and review.

BACKGROUND: Parathyroid hormone (PTH) measurements can be falsely elevated due to the hormone binding to other molecules (macro-PTH) or immunoassay interference with heterophile, human anti-animal or other antibodies. This is rare but could lead to incorrect diagnosis, unnecessary investigations or avoidance of teriparatide treatment. We report a case of falsely high PTH levels due to assay interference and review the literature on cases of spuriously elevated PTH. CASE REPORT: An 87-year-old woman attending our bone health clinic with osteoporosis had persistently elevated PTH (383-784 pg/ml) using the Roche Cobas e801 immunoassay despite having normal serum calcium, phosphate, 25 hydroxyvitamin D (> 50 nmol/l) and eGFR (> 60 ml/min). To rule out falsely elevated PTH, a polyethylene glycol precipitation (PEG) test was performed which recovered less than 10% of the hormone resulting in a normal level. PTH was also tested on a different assay (Atellica Siemens) that identified a result of 27 pg/ml. The findings were consistent with immunoassay interference likely due to heterophile antibodies giving rise to a spuriously high PTH. DISCUSSION: The presence of unexpectedly high PTH levels should alert physicians to the possibility of false results due to assay interference or macro-PTH. This highlights the importance of clinically correlating results and of good communication with the testing laboratory. Here, we present the case of an 87-year-old woman with spuriously elevated PTH levels due to immunoassay interference likely mediated by heterophile antibodies. The presence of unexpectedly high PTH levels should prompt consideration of the possibility of false results due to assay interference or macro-PTH.

Postprandial effect of dietary fat quantity and quality on arterial stiffness and wave reflection: a randomised controlled trial.

BACKGROUND: Arterial stiffness is a component of vascular function and an established risk factor for cardiovascular disease. There is a lack of conclusive evidence on the effect of a meal rich in monounsaturated fat (MUFA) compared with an isoenergetic meal rich in saturated fat (SFA) on postprandial vascular function and specifically on arterial stiffness. METHODS: Twenty healthy, non-smoking males (BMI 24 ± 2 kg/m2; age 37.7 ± 14.4 y) participated in this single-blind, randomised, cross-over dietary intervention study. Each subject was randomised to receive a high-fat test-meal (3 MJ; 56 ± 2 g fat) at breakfast on 2 separate occasions, one rich in oleic acid (MUFA-meal) and one rich in palmitic acid (SFA-meal), and the meals were isoenergetic. Blood pressure (BP), arterial stiffness (PWV) and arterial wave reflection (augmentation index, AIx) were measured using applanation tonometry at baseline and every 30 minutes up to 4 hours after the ingestion of the test-meals. RESULTS: All subjects completed both arms of the dietary intervention. There was no significant difference in BP parameters, PWV or AIx at baseline between the two treatments (P > 0.05). There was a significant increase in brachial and aortic BP, mean arterial pressure (MAP), heart rate and PVW (time, P < 0.05) over the four hours after consumption of the fat-rich test-meal although the increase in PWV was no longer significant when adjusted for the increase in MAP. There was no difference in PWV between the two treatments (treatment*time, P > 0.05). There was a significant reduction in AIx (time, P < 0.05) over the four hour postprandial period although this was no longer significant when adjusted for the increase in heart rate and MAP (time, P > 0.05). There was no difference in AIx between the two treatments (treatment*time, P > 0.05). However, the reduction in heart rate corrected augmentation index (AIx75) was significant when corrected for the increase in MAP (time, P < 0.01) with no differential effect of the treatments (treatment*time, P > 0.05). CONCLUSIONS: This study has demonstrated a BP dependent increase in PWV and a decrease in arterial wave reflection in the four hour period in response to a high-fat meal. There was no evidence however that replacement of some of the SFA with MUFA had a differential effect on these parameters. The study highlights the need for further research to understand the effects of the substitution of SFA with MUFA on non-serum, new and emerging risk factors for CVD such as arterial stiffness.

Elevated tumour marker: an indication for imaging?

INTRODUCTION: The purpose of this study was to evaluate the utility of imaging examinations in patients with elevated tumour markers when (a) the tumour marker is not validated for as a primary diagnostic test; (b) the patient had no personal history of cancer and (c) the patient had no other imaging indication. MATERIALS AND METHODS: Patients without known cancer who had abnormal carcinoembryonic antigen, CA19-9, CA125 and/or CA15-3 serology over a one-year period were included. A retrospective medical record review was performed to assess the number of these cases who underwent imaging because of 'elevated tumour marker' in the absence of a clinical indication for imaging. The number and result of these imaging studies were evaluated. RESULTS: Eight hundred and nineteen patients were included. Of those, 25 patients (mean age: 67.8 [range 41-91] y), were imaged to evaluate: 'elevated tumour marker'. They underwent 29 imaging studies (mean [+/-standard deviation (SD)] per patient = 1.2 [+/-0.4]), and had 42 elevated tumour marker serology tests (mean [+/-SD] per patient = 1.7 [+/-0.7]). Four patients had >1 imaging test. No patient had an imaging study which diagnosed a malignancy or explained the elevated tumour marker. CONCLUSION: The non-judicious use of tumour markers can prompt further unnecessary investigations including imaging. In this study, there was no positive diagnostic yield for imaging performed for investigation of 'elevated tumour marker'. 'Elevated tumour marker', in the absence of a known underlying malignancy, should not be considered an independent indication for imaging.

Bone histopathology and densitometry comparison between cyclosporine a monotherapy and prednisolone plus azathioprine dual immunosuppression in renal transplant patients.

BACKGROUND: No study has compared the bone histopathologic findings in renal transplant patients receiving cyclosporine A (CsA) monotherapy with those in patients receiving a non-CsA regimen. The aim of this study was to compare bone densitometry and histomorphometry findings in patients receiving CsA monotherapy versus those receiving azathioprine + prednisolone dual therapy. METHODS: A bone biopsy and densitometry were performed in 13 patients receiving CsA monotherapy and 12 patients receiving azathioprine + prednisolone, who had been on these regimens since the time of transplantation. Fourteen men and 11 women, age 51+/-12 years, with 140+/-75 months since transplantation, were included. RESULTS: A low bone mineral density (BMD) was observed in patients on both immunosuppressive schemes-most notably at the distal radius and less significantly at the lumbar spine. No significant differences in BMD were observed between immunosuppressive groups. Histopathologic analysis of the group as a whole revealed mixed uremic bone disease in 42%, adynamic bone in 29%, hyperparathyroid disease in 17%, and normal bone in 12%. Patients showed a slight increase in osteoclast number and function, decreased osteoblast number and function, and retardation of dynamic parameters. No differences in histopathologic diagnosis or histomorphometric findings were observed between the immunosuppressive therapy groups. In addition to the immunosuppressive drugs, male gender and old age negatively affected bone mass. CONCLUSIONS: Both prednisolone and CsA were associated with slight osteoclast stimulation and osteoblast suppression and marked retardation of mineral apposition and bone formation rates. Both drugs were also associated with reduced BMD at the axial and appendicular skeleton, even though a nonsignificant trend to a better-preserved lumbar spine BMD was observed in the CsA group.

Obesity therapy: altering the energy intake-and-expenditure balance sheet.

Obesity is associated with numerous health complications, which range from non-fatal debilitating conditions such as osteoarthritis, to life-threatening chronic diseases such as coronary heart disease, diabetes and certain cancers. The psychological consequences of obesity can range from lowered self-esteem to clinical depression. Despite the high prevalence of obesity and the many advances in our understanding of how it develops, current therapies have persistently failed to achieve long-term success. This review focuses on how fat mass can be reduced by altering the balance between energy intake and expenditure.