Parathyroid hormone-related protein: an unusual mechanism for hypercalcemia in sarcoidosis

A Case of Hypercalcemia from PTHrP-Producing Fibromyxoid Sarcoma Responsive to Glucocorticoid Therapy

The treatment of parathyroid hormone-related protein (PTHrP)-mediated hypercalcemia of malignancy includes treating the malignancy, intravenous fluids, and anti-resorptive therapies such as zoledronic acid or denosumab. PTHrP-mediated hypercalcemia has been reported in benign conditions such as systemic lupus erythematous (SLE) and sarcoidosis and appears to be responsive to glucocorticoids. We report a case of PTHrP-induced hypercalcemia due to a malignancy-low grade fibromyxoid sarcoma-that responded to glucocorticoid treatment. This is the first report of glucocorticoids controlling PTHrP-mediated hypercalcemia of malignancy. Immunohistochemistry of the surgical pathology localized PTHrP staining to the vascular endothelial cells within the tumor. Further studies are needed to elucidate the mechanism of glucocorticoid action in the treatment of PTHrP-mediated hypercalcemia of malignancy.

Musculoskeletal Manifestations of Sarcoidosis

Since its initial description in the late 19th century, sarcoidosis has been extensively studied. Although the general mechanism of immune activation is known, many details especially in the context of disease associations are still missing. One of such associations is the musculoskeletal complications that are widely variable in terms of presentation and response to treatment. Sarcoidosis can involve the joints leading to acute and, less commonly chronic, arthritis. While acute arthritis is mostly self-resolving in nature, chronic arthritis may lead to deformity and destruction of the joint. Sarcoidosis can also involve the muscles, leading to different pathologies primarily categorized according to the clinical presentation, despite the efforts to find a new classification based on imaging, histological, and clinical findings. The bones can be directly and indirectly affected. Different types of bone lesions have been described, although around half of these patients remain asymptomatic. Osteoporosis, increased risk of fractures, hypercalcemia, and hypercalciuria are examples of the indirect effect of sarcoidosis on the bones, possibly contributed to elevated levels of calcitriol. Nevertheless, sarcoidosis can be associated with small-vessel, medium-vessel, and large vessel vasculitis, although it is frequently difficult to differentiate between the co-existence of a pure vasculitis and sarcoidosis and sarcoid vasculitis.

Hypercalcaemia in Mycobacterium kansasii pulmonary infection

A gentleman in his 60s with end-stage kidney disease status post kidney transplantation on prednisone and tacrolimus presented with generalised weakness for 7 days, associated with altered mental status. Investigations revealed pancytopenia, acute kidney injury, hypercalcaemia, decreased parathyroid hormone (PTH) and normal calcitriol levels. CT of the chest showed multifocal lung opacities suspicious for malignancy. Bronchoscopy with biopsy yielded no malignant cells, and bronchoalveolar lavage specimens grew Mycobacterium kansasii The patient was treated with bisphosphonates, calcitonin and antibiotics for non-tuberculous mycobacteria pulmonary infection, with improvement in serum calcium levels, and was discharged after 5 weeks of hospitalisation.The work-up for hypercalcaemia begins with PTH measurement, and low PTH levels are consistent with malignancy, immobilisation and granulomatous diseases. Hypercalcaemia in the lattermost is classically caused by overproduction of calcitriol by activated macrophages. However, there are case reports of mycobacterial infections with hypercalcaemia despite normal calcitriol levels, supporting the existence of an additional mechanism of hypercalcaemia in granulomatous infections.

Intraoperative parathormone increase after focused parathyroidectomy in a patient with sarcoidosis - Case report

Introduction

Hypercalcaemia is most commonly a sign of primary hyperparathyroidism but can also be a sign of an active granulomatous disease. Standard treatment for primary hyperparathyroidism caused by a solitary parathyroid gland adenoma identified by localisation studies is minimally invasive focused parathyroidectomy. If unsuccessful, bilateral neck exploration is recommended.

Case presentation

We report the case of hypercalcaemia and ostheoporosis in a 63-year -old woman with a history of sarcoidosis and suspected primary hyperparathyroidism. Localisation studies for parathyroid adenoma were inconclusive due to active cervical and mediastinal granulomatous lymph nodes. Sarcoidosis was treated with corticosteroids but hypercalcaemia persisted. Focused parathyroidectomy was attempted with intraoperative parathyroid hormone measurement but an increase in parathyroid hormone levels was observed. However, with high clinical probability of a successfully removed adenoma and frozen section evaluation, we decided not to proceed with bilateral neck exploration. Serum parathyroid hormone and calcium levels dropped accordingly the following day.

Clinical discussion

We explored all possible underlying mechanisms for persistent elevated parathyroid hormone level described in literature.

Conclusion

We conclude that Wisconsin Criteria with intraoperative parathyroid hormone measured 20 minutes after adenoma removal should be applied in such cases.

A case of extrapulmonary tuberculosis in a patient with end-stage renal disease with elevated parathyroid hormone-related protein

The diagnosis of extrapulmonary tuberculosis in patients with end-stage renal disease can be challenging as the signs and symptoms are often non-specific. In this study, we present a case of extrapulmonary tuberculosis in an Ethiopian woman with end-stage renal disease who had subcarinal and right hilar lymphadenopathy, moderate sized right pleural effusion, hypercalcemia, and elevated parathyroid hormone–related protein in the setting of an elevated 1,25-dihydroxyvitamin D. After being started on appropriate tuberculosis treatment, patient’s parathyroid hormone–related protein level decreased and calcium level normalized. Our literature review showed that the elevation of parathyroid hormone–related protein in extrapulmonary tuberculosis has not been well studied, and it is our aim to explore the role of parathyroid hormone–related protein in extrapulmonary tuberculosis.

Sarcoidosis and calcium homeostasis disturbances-Do we know where we stand?

The majority of cases involving hypercalcemia in the setting of sarcoidosis are explained by the overproduction of calcitriol by activated macrophages. Vitamin D takes part in the regulation of granuloma formation. However, using vitamin D metabolites to assess the activity of the disease is still problematic, and its usefulness is disputable. In some cases, though, a calcium metabolism disorder could be a valuable tool (i.e. as a marker of extrathoracic sarcoidosis). Although sarcoidosis does not cause a decrease in bone mineral density, increased incidence of vertebral deformities is noted. Despite increasing knowledge about calcium homeostasis disorders in patients with sarcoidosis, there is still a need for clear guidelines regarding calcium and vitamin D supplementation in these patients.

ASIA syndrome, calcinosis cutis and chronic kidney disease following silicone injections. A case-based review

An immunologic adjuvant is a substance that enhances the antigen-specific immune response preferably without triggering one on its own. Silicone, a synthetic polymer used for reconstructive and cosmetic purposes, can cause, once injected, local and/or systemic reactions and trigger manifestations of autoimmunity, occasionally leading to an overt autoimmune disease. Siliconosis, calcinosis cutis with hypercalcemia and chronic kidney disease have all been reported in association with silicone injection. Here, we describe a case of autoimmune/auto-inflammatory syndrome induced by adjuvants, calcinosis cutis and chronic kidney disease after liquid silicone multiple injections in a young man who underwent a sex reassignment surgery, followed by a review of the literature. To our knowledge, this is the first report describing the concomitance of the three clinical conditions in the same patients. The link between silicone and the immune system is not completely understood yet and requires further reports and investigations with long-term data, in order to identify the main individual and genetical risk factors predisposing to the wide spectrum of the adjuvant-induced responses.

ENDOCRINE MANIFESTATIONS OF PRIMARY HYPEROXALURIA

OBJECTIVE

Primary hyperoxaluria type 1 (PH1) is a rare metabolic disorder of oxalate overproduction. It is associated with urolithiasis and nephrocalcinosis, which progress to end-stage renal disease and systemic oxalosis. As oxalate deposits in tissues, non-parathyroid hormone (nonPTH)-mediated hypercalcemia, oxalate osteopathy, primary hypothyroidism, and primary hypogonadism develop. In this review, we will present a case of PH1 and provide an overview of this clinical entity and its endocrine manifestations.

METHODS

We conducted a PubMed search for articles related to PH1. The terms "primary hyperoxaluria," "nonPTH mediated hypercalcemia," "hypothyroidism," and "hypogonadism" were used to identify pertinent literature.

RESULTS

Given the rarity of PH1, there is scant literature regarding the incidence and clinical significance of endocrine manifestations of this disorder. There are rare reports of hypercalcemia secondary to osteoclast-stimulating activity of macrophages in bone granulomas, which occur in response to oxalate deposits. We report that hypercalcemia may also be mediated by 1,25-dihydroxyvitamin D and PTH-related protein (PTHrP). Primary hypothyroidism and primary hypogonadism are thought to be due partly to calcium oxalate deposition in thyroid and testicular tissue. The presented case is the first to report PTHrP-mediated hypercalcemia and primary hypogonadism in a patient with PH1.

CONCLUSION

PH1 is a metabolic disease with significant morbidity and mortality. Owing to its rarity, it is not widely recognized in the field of endocrinology, despite presenting with several endocrinopathies. Recognition of endocrine disturbances can result in early and successful treatment, limiting morbidity and improving quality of life in these challenging patients.

ABBREVIATIONS

1,25(OH)₂D= 1,25-dihydoxyvitamin D AGT = alanine:glyoxylate aminotransferase ESRD = end-stage renal disease GRHPR = glyoxylate reductase-hydroxypyruvate reductase nonPTH = non-parathyroid hormone PH = primary hyperoxaluria pQCT = peripheral quantitative computed tomography PTH = parathyroid hormone PTHrP = parathyroid hormone-related protein T4 = thyroxine TSH = thyroid-stimulating hormone.

An unexpected cause of severe and refractory PTH-independent hypercalcemia: case report and literature review

Hypercalcemia is a common condition in the internal medicine practice. Sometimes its cause is not readily apparent, so extensive investigation is appropriate. Here we report an unexpected cause for hypercalcemia in an elderly woman. The case of an 82-years old woman with PTH-independent hypercalcemia, lymphocytosis, normal serum 1,25 (OH)vitamin D levels, and low serum PTHrp levels, is described. Medical history and complementary investigation were unremarkable, except for increased metabolic activity in the glutei regions, as measured by whole body 18F-FDG PET-CT. Reviewing her medical history, her sister recalled that she had been submitted to intramuscular methylmethacrylate injections, for cosmetic purposes, five years before presentation, which was confirmed by muscle biopsy. Low calcium intake, parenteral bisphosphonates, calcitonin, and glucocorticoids were used to control serum calcium levels. Methylmethacrylate injections, used cosmetically, are a new cause for hypercalcemia, even after many years. Hypercalcemia was probably due to calcitriol overproduction in foreign body granulomas. Persistent reactive lymphocytosis could be a clue for this inflammatory cause of hypercalcemia.

[Sarcoidosis in childhood. A rare systemic disease]

BACKGROUND

Sarcoidosis is a systemic disease of unknown etiology that rarely occurs in children. It usually affects the lungs, however, it may involve various organs. It occasionally affects the general condition, and causes fever, hepatomegaly and splenomegaly.

CASE REPORT

We report the case of a twelve-year-old adolescent with late-onset childhood sarcoidosis which diagnosis was confirmed by lymph node histopathological study. The patient presented general condition, hypercalcemia, erythema nodosum, severe lung disorders, lymphadenopathy, hepatomegaly and testicular mass. He received treatment with steroids, with excellent clinical response.

CONCLUSIONS

We highlight the importance of considering the diagnosis of sarcoidosis in patients with hepatomegaly, lymphadenopathy, diffuse lung damage, erythema nodosum, testicular mass and hypercalcemia, as well as the need for a multidisciplinary approach to assess multiple organ involvement and the early beginning of steroid treatment in order to prevent the progression of the disease.

Sarcoidosis-related hypercalcaemia due to production of parathyroid hormone-related peptide

Hypercalcaemia is frequently observed in patients with sarcoidosis. This is classically attributed to ectopic production of 1,25 dihydroxy vitamin D by sarcoid granulomas. We present a case of sarcoidosis-related hypercalcaemia with normal vitamin D levels. In this patient, production of parathyroid hormone-related peptide (PTHrp) was the cause for sarcoidosis-induced hypercalcaemia. As such, plasma PTHrp levels were increased and bone marrow granulomas stained positively for PTHrp expression. Medium-dose prednisolone treatment improved symptoms of sarcoidosis and normalised serum calcium, and PTHrp concentrations. Thus, production of PTHrp may be the cause for hypercalcaemia in some patients with sarcoidosis.

[Disorders of calcium metabolism]

The majority of clinical complaints derive from disorders of calcium metabolism and are associated with a wide variety of clinical symptoms caused by numerous diseases with entirely different types of pathophysiology. The prognosis varies from favorable to fatal depending on the pathophysiology of the underlying disorder of calcium metabolism; therefore, the diagnostic work-up aims to quickly identify the underlying disease causing the disturbance in calcium homeostasis. Every clinical situation with a diminished state of calcium absorption is treated with calcium and vitamin D in varying doses whereas every disorder with an increased calcium absorptive or resorptive state is treated with improved diuresis in addition to antiresorptive drugs, such as bisphosphonates. In many situations the management of a disturbed calcium balance requires an interdisciplinary approach in order to treat the underlying disease in parallel with correction of the calcium homeostasis.

Approaches to the treatment of some of the troublesome manifestations of sarcoidosis

Sarcoidosis can be a major therapeutic challenge given its multiplicity of clinical presentations, variable combination of organ involvement and severity, and unpredictable longitudinal behaviour. Six manifestations of sarcoidosis are especially difficult to manage because of (i) an incomplete knowledge of causation - fatigue and small fibre neuropathy, (ii) the rare occurrence in sarcoidosis - intra-abdominal complications or (iii) the potentially life-threatening consequences in some patients - neurological disease, pulmonary hypertension and hypercalcaemia. In none of these situations have a prospective, double-blind, placebo-controlled trial of any therapy been conducted. Despite this absence of any firm evidence base to support therapeutic recommendations, these six entities can be extremely problematic for the practising clinician. It is for this reason that we have focused in this review on these six disease manifestations and provided a synopsis of each problem together with suggested treatment approaches, based on an analysis of the current literature.

Serum vitamin D levels may not reflect tissue-level vitamin D in sarcoidosis

Hypercalcemia in sarcoidosis is due to three mechanistic reasons: (1) systemic conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D by the enzyme 1-α hydroxylase produced by activated monocyte/macrophage system, (2) production of parathormone-related peptide (PTHrP) by the sarcoid granuloma, (3) tissue-level conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D by 1-αhydroxylase produced by local monocyte/macrophage system in the sarcoid granuloma. We report two cases of one proposed mechanism of hypercalcaemia in sarcoidosis (mechanism 3). Both individuals presented with sarcoidosis and 25-hydroxyvitamin D deficiency and developed symptomatic hypercalcaemia with vitamin D replacement. Given their low serum parathormone and parathormone-related peptide levels, low serum 25-hydroxy vitamin D and normal serum 1,25-dihydroxyvitamin D, the systemic 25-hydroxy vitamin D deficiency may not have reflected an increased activity of vitamin D at the local granulomatous tissue level.

Cervical lymph node sarcoidosis mimicking a parathyroid adenoma: a clinical case

We report a case of cervical lymph node sarcoidosis misdiagnosed as parathyroid adenoma. This is the second case described in the literature in which lymph node sarcoidosis was misdiagnosed as parathyroid adenoma on Tc-99m sestamibi (MIBI) scan, the first case localized in the neck. A 64-year-old woman presented with a hypercalcemia. Neck ultrasonography revealed a paratracheal hypoechoic mass of 15 mm with peripheral vascularization. MIBI scan and SPECT/CT identified a MIBI-positive area corresponding to the nodule detected by ultrasonography suggestive for a lower right parathyroid adenoma. A mass interpreted as the lower parathyroid was excised associated to a total thyroidectomy. Pathologic examination revealed a granulomatous lymph node consistent with active sarcoidosis. Sarcoidosis should be suspected as a cause of unexplained hypercalcemia and the differential diagnosis of hypercalcemia, even in presence of MIBI uptake, must include sarcoidosis localized in an isolated cervical lymph node.

Coexisting primary hyperparathyroidism and sarcoidosis cause increased angiotensin-converting enzyme and decreased parathyroid hormone and phosphate levels

CONTEXT

Primary hyperparathyroidism (PHPT) and sarcoidosis may separately contribute to abnormal calcium and phosphate metabolism via different mechanisms, and their coexistence is infrequently reported.

OBJECTIVE

We sought to characterize a group of 50 patients with coexisting PHPT and sarcoidosis in our institution to evaluate their clinical and laboratory characteristics.

DESIGN AND SETTING

This was a retrospective observational study of patients with both disorders at our institution between January 1980 and December 2011.

OUTCOME

A cohort of 50 patients was identified, with mean ± SD age 59.6 ± 13.9 years and 86% women. Serum calcium in the cohort was 11.1 ± 1.1 mg/dL, phosphate was 3.3 ± 0.6 mg/dL, and PTH was 76 ± 42 pg/mL. Serum 25-hydroxyvitamin D was 25 ± 9 ng/mL, and serum 1,25-dihydroxyvitamin D was 51 ± 20 pg/mL; 24-hour urine calcium was 275 ± 211 mg. In subjects with sarcoidosis, serum angiotensin-converting enzyme (ACE) was 47.2 ± 37.4 U/L. Sarcoidosis was diagnosed first in 50% of patients, PHPT was diagnosed first in 16% of patients, and sarcoidosis and PHPT were both diagnosed within 6 months of each other in 30% of patients. The interval between the 2 diagnoses when sarcoidosis was diagnosed first was 15.5 ± 12.4 years and was 5.5 ± 6.0 years when PHPT was diagnosed first. Patients with PHPT who had active sarcoidosis had higher serum ACE levels (60.9 ± 38.1 vs 20.2 ± 14.0 U/L, P <.0001), lower PTH levels (60 ± 24 vs 96 ± 41 pg/mL, P = .01), and lower phosphate levels (2.7 ± 0.6 vs 3.2 ± 0.5 mg/dL, P = .02).

CONCLUSIONS

Fifty patients with coexisting PHPT and sarcoidosis are described, with patients with PHPT coexisting with clinically active sarcoidosis having increased serum ACE levels and decreased serum PTH and phosphate levels compared with those with inactive sarcoidosis.

Hypercalcemia in disseminated coccidioidomycosis: expression of parathyroid hormone-related peptide is characteristic of granulomatous inflammation

BACKGROUND

Hypercalcemia is an uncommon complication of disseminated granulomatous infections. The pathogenesis of hypercalcemia associated with infection is not clear.

METHODS

We investigated a case of disseminated coccidioidomycosis with hypercalcemia. We used a sensitive radioimmunoassay to measure serum parathyroid hormone-related peptide (PTHrP) and a mouse monoclonal antibody to PTHrP to immunostain biopsies.

RESULTS

We found elevated serum levels of PTHrP while the patient was hypercalcemic that became undetectable when serum calcium normalized. We also found that the inflammatory cells and some surrounding tissues in skin biopsies expressed PTHrP. PTHrP was expressed by all biopsied lesions of patients with coccidioidomycosis that we examined, whether localized to the lung or disseminated, but no other cases were hypercalcemic. PTHrP was also expressed by the 3 mycobacterial granulomas we examined, and in a lymph node from a patient with sarcoidosis.

CONCLUSIONS

The expression of PTHrP is a property of infectious granulomas regardless of etiology or the tissue involved, suggesting that PTHrP expression is part of the normal granulomatous immune response. Hypercalcemia may result if there is disseminated infection and multiple granulomas. We propose that excess production of PTHrP is the cause of hypercalcemia in granulomatous infections.