Genetic Diseases of Vitamin D Metabolizing Enzymes

Vitamin D metabolism involves 3 highly specific cytochrome P450 (CYP) enzymes (25-hydroxylase, 1α-hydroxylase, and 24-hydroxylase) involved in the activation of vitamin D₃ to the hormonal form, 1,25-(OH)₂D₃, and the inactivation of 1,25-(OH)₂D₃ to biliary excretory products. Mutations of the activating enzymes CYP2R1 and CYP27B1 cause lack of normal 1,25-(OH)₂D₃ synthesis and result in rickets whereas mutations of the inactivating enzyme CYP24A1 cause build-up of excess 1,25-(OH)₂D₃ and result in hypercalcemia, nephrolithiasis, and nephrocalcinosis. This article reviews the literature for 3 clinical conditions. Symptoms, diagnosis, treatment, and management of vitamin D-dependent rickets and idiopathic infantile hypercalcemia are discussed.

A rare case report of multiple myeloma presenting with paralytic ileus and type II respiratory failure due to hypercalcemic crisis

RATIONALE

Paralytic ileus is characterized by the signs and symptoms of intestinal obstruction but without any mechanical lesions in the intestinal lumen. Several medical and surgical conditions can lead to this ailment, such as electrolyte disturbances that impair intestinal motility. However, hypercalcemia secondary to multiple myeloma as a major cause of paralytic ileus has rarely been reported.

PATIENT CONCERNS

The patient got severe constipation with difficulty in the passage of both gas and feces for 7 days.

DIAGNOSES

The patient was diagnosed with a small intestinal obstruction initially and then developed type II respiratory failure. Investigations revealed hypercalcemic crisis, and examination of a bone marrow aspirate was consistent with multiple myeloma.

INTERVENTIONS

Conservative treatment was administered for the intestinal obstruction, consisting of food and water deprivation, gastrointestinal decompression, colonic irrigation, intravenous fluid transfusion, anti-inflammatory therapy. Invasive respiratory support was provided after type II respiratory failure occurred and salmon calcitonin was used to reduce the blood calcium level. Further therapy was given by the Department of Hematology and Oncology in our hospital after the diagnosis of multiple myeloma.

OUTCOMES

Spontaneous respiration and gastrointestinal function were restored after the correction of hypercalcemia.

LESSONS

An appropriate diagnostic approach is needed in emergency practice to identify the paralytic ileus and type II respiratory failure caused by hypercalcemia secondary to multiple myeloma.

Development of a Multivariate Predictive Model to Estimate Ionized Calcium Concentration from Serum Biochemical Profile Results in Dogs

BACKGROUND

Ionized calcium concentration is the gold standard to assess calcium status in dogs, but measurement is not always available.

OBJECTIVES

(1) To predict ionized calcium concentration from biochemical results and compare the diagnostic performance of predicted ionized calcium concentration (piCa) to those of total calcium concentration (tCa) and 2 corrected tCa formulas; and (2) to study the relationship between biochemical results and variation of measured ionized calcium concentration (miCa).

ANIMALS

A total of 1,719 dogs with both miCa and biochemical profile results available.

METHODS

Cross-sectional study. Using 1,200 dogs, piCa was determined using a multivariate adaptive regression splines model. Its accuracy and performance were tested on the remaining 519 dogs.

RESULTS

The final model included creatinine, albumin, tCa, phosphorus, sodium, potassium, chloride, alkaline phosphatase, triglycerides, and age, with tCa, albumin, and chloride having the highest impact on miCa variation. Measured ionized calcium concentration was better correlated with piCa than with tCa and corrected tCa and had higher overall diagnostic accuracy to diagnose hypocalcemia and hypercalcemia, but not significantly for hypercalcemia. For hypercalcemia, piCa was as sensitive (64%) but more specific (99.6%) than tCa and corrected tCa. For hypocalcemia, piCa was more sensitive (21.8%) and as specific (98.4%) as tCa. Positive and negative predictive values of piCa were high for both hypercalcemia (90% and 98%, respectively) and hypocalcemia (70.8% and 87.7%, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Predicted ionized calcium concentration can be obtained from readily available biochemical and patient results and seems more useful than tCa and corrected tCa to assess calcium disorders in dogs when miCa is unavailable. Validation on external data, however, is warranted.

Electrolytes: Calcium Disorders

A normal serum calcium level is 8 to 10 mg/dL. The diagnosis of hypercalcemia (ie, levels 10.5 mg/dL or greater) should be confirmed with an albumin-adjusted or ionized calcium level. The two most common causes of hypercalcemia are hyperparathyroidism and malignancy. Drugs, notably lithium and thiazide diuretics, also can cause hypercalcemia. Patients with severe or symptomatic hypercalcemia should be treated initially with hydration to decrease calcium levels. The evaluation should include a parathyroid hormone (PTH) level. If the PTH level is low, cancer is a likely cause, particularly multiple myeloma, breast cancer, or lymphoma. If the PTH level is normal or elevated, hyperparathyroidism is the likely cause. Symptomatic patients with hyperparathyroidism and patients with certain clinical markers should be considered for surgery. For patients with mild disease, monitoring is an option. Hypocalcemia often is caused by vitamin D deficiency. Symptomatic patients and patients with calcium levels less than 7.6 mg/dL should be treated with intravenous calcium gluconate; concomitant magnesium deficiency should be addressed. There is no evidence that routine calcium and vitamin D supplementation reduces the risk of fractures, but studies have shown that vitamin D supplementation does decrease the number of falls in older adults at risk.

Cytological Features of the Large Cell Variant of Small Cell Ovarian Carcinoma in Young Patients with Hypercalcemia: Histological Findings and Review of the Literature

OBJECTIVE

To present the cytological features of a very rare and lethal ovarian neoplasm occurring in the young.

STUDY DESIGN

We reviewed the cytological findings as they presented in touch imprints obtained from an ovarian mass sent to our department for frozen section investigation.

RESULTS

Smears were highly cellular. The cells were of intermediate size with a moderate amount of microvacuolated, pale, or eosinophilic cytoplasm with indistinct cell borders. The nuclei were of round or oval shape with mild to moderate atypia and indistinct nucleoli.

CONCLUSIONS

The diagnosis of small cell carcinoma of the ovary can be challenging even histologically. Cytology can be an invaluable adjunct to hematoxylin-eosin sections both pre- or intraoperatively. Although it is a very rare occurrence and cytological results are almost absent in the literature, our case can make cytopathologists more acquainted with the cytological features of this rare tumor entity especially in association with a characteristic clinical profile. Furthermore, the cytological features of small cell carcinoma of the ovary, large cell variant, have only rarely been described in the literature.

Factors influencing pre-operative urinary calcium excretion in primary hyperparathyroidism

OBJECTIVE

Normal or elevated 24-hour urinary calcium (Ca) excretion is a diagnostic marker in primary hyperparathyroidism (PHPT). It is used to distinguish familial hypocalciuric hypercalcaemia (FHH) from PHPT by calculating the Ca/creatinine clearance ratio (CCCR). The variance of CCCR in patients with PHPT is considerable. The aim of this study was to analyse the parameters affecting CCCR in patients with PHPT.

DESIGN

The data were collected prospectively. Patients with sporadic PHPT undergoing successful surgery were included in a retrospective analysis.

PATIENTS

The analysis covered 381 patients with pre-operative workup 2 days before removal of a solitary parathyroid adenoma.

MEASUREMENTS

The impact of serum Ca and 25-hydroxyvitamin D3 (25-OH D3) on CCCR.

RESULTS

The coefficient of determination (R² ) in the multivariable model for CCCR consisting of age, Ca, 25-OH D3, 1,25-dihydroxyvitamin D3 (1,25-(OH)2 D3), testosterone (separately for males and females), intact parathyroid hormone (iPTH) and osteocalcin was 25.8%. The only significant parameters in the multivariable analysis were 1,25-(OH)2 D3 and osteocalcin with a drop in R² of 15.4% (P<.001) and 2.4% (P=.006), respectively. Bone mineral densities at the lumbar spine, distal radius and left femoral neck were not associated with CCCR (r=-.08, r=-.10 and r=-0.09).

CONCLUSIONS

In multivariable analysis, 1,25-(OH)2 D3 and osteocalcin were the only factors correlating with CCCR. Vitamin D3 replacement may therefore impair the diagnostic value of CCCR and increase the importance of close monitoring of urinary Ca excretion during treatment.

Milk-Alkali syndrome induced by H1N1 influenza vaccine

Milk-Alkali syndrome (MAS) consists of a triad of hypercalcemia, metabolic alkalosis, and acute renal failure. We hereby report a 75-year-old Indian gentleman who presented to our emergency department with a history of generalized weakness and easy fatigability. Investigations were consistent with MAS secondary to calcium carbonate and calcitriol treatment to prevent osteoporosis, aggravated by H1N1 influenza vaccine. The patient was treated with hemodialysis and zoledronate. To our knowledge, this is the first reported case of such association in the literature.

Hypercalcaemia - presentation and management

Hypercalcaemia is a common disorder normally caused by primary hyperparathyroidism (PHPT) or malignancy. A proportion of cases present as an emergency, which carries a significant mortality. Emergency management of hypercalcaemia is based on intravenous rehydration with normal saline but when this is inadequate, bisphosphonate therapy is used; more recently the novel anti-resorbtive agent denosumab has been shown to have a useful role in treatment. It is estimated that up to 10% of all cases of PHPT presenting under the age of 45 years have an underlying genetic predisposition; nine potentially causative genes are now recognised and may be screened in routine clinical practice. Although parathyroidectomy is the only curative treatment for PHPT, this is indicated in a minority of cases. Many cases can be adequately managed conservatively and guidance from the 4th international workshop on the management of asymptomatic PHPT has recently been updated in a consensus statement.

Palisaded neutrophilic and granulomatous dermatitis as a novel cause of hypercalcemia: A case report

RATIONALE

Palisaded neutrophilic and granulomatous dermatitis (PNGD) is a benign, inflammatory dermatosis with distinct histopathological features often observed in patients with systemic diseases. There were no reports of PNGD without underlying systemic diseases as an underlying cause of hypercalcemia. Herein, we report a case of a 62-year-old man with hypercalcemia due to PNGD, but with no underlying systemic diseases, including tuberculosis, sarcoidosis, or vasculitis.

PATIENT CONCERNS

Laboratory tests showed an elevated C-reactive protein level, an elevated corrected calcium level, a normal 25-hydroxyvitamin D level, and an elevated 1,25-dihydroxyvitamin D level. There were no other abnormalities to explain the hypercalcemia. Positron emission tomography-computed tomography showed abnormal uptake in his skin. Histopathological examination of the skin showed palisaded granulomatous infiltrate in the dermis. Neutrophils, degenerated collagen, and fibrin were present in the centers of the palisades without prominent mucin. There were no eosinophils, central necrosis, or necrotizing vasculitides. These features were consistent with PNGD.

DIAGNOSES

A diagnosis of PNGD with hypercalcemia was established.

INTERVENTIONS

Oral prednisolone was administered to the patient.

OUTCOMES

After treatment, his symptoms resolved, and his calcium, 1,25-dihydroxyvitamin D and CRP levels returned to normal. Skin specimens before and after treatment were assessed using immunohistochemistry for 1a-hydroxylase. Granuloma and epidermal cells were 1a-hydroxylase-positive before treatment. After treatment, the granuloma diminished in size and the 1ahydroxylase-positive areas of the epidermal cells decreased.

LESSONS

This case was particularly unique because increased 1a-hydroxylase expression in the granuloma and epidermal cells seemed to result in hypercalcemia due to excessive transformation of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D. Physicians should consider PNGD as an underlying cause of hypercalcemia.

[Diagnostic approach and management of hypercalcaemia in dogs exemplary of primary hyperparathyroidism]

Hypercalcaemia can be caused by many different diseases. This article summarizes the causes, pathophysiologic mechanisms and diagnostic procedures as well as treatment recommendations. The main focus is on hypercalcaemia in primary hyperparathyroidism (PH), complemented by a case report. An elevated total calcium level should generally be investigated and verified by measurement of ionized calcium concentration. The further diagnostic approach depends on the phosphate level. Tumour screening, measurement of parathormone and parathromone-related protein and sonography of parathyroid glands may be necessary. If the calcium-phosphate-product exceeds 60 mg/dl, there is a risk of tissue mineralisation and a rapid treatment of hypercalcaemia is required. For acute therapy, sodium chloride infusion, furosemide and glucocorticoids can be used. Glucocorticoids should only be given after strict indication and after a definite diagnosis. For long-term management, bisphosphates, particularly alendronate, are increasingly used successfully. Causal therapy of PH can be performed by parathyreoidectomy, heat ablation or ethanol ablation. Thereafter, particularly in cases of severe preoperative hypercalcaemia, hypocalcaemia can occur. Treatment is performed using vitamin D₃ (calcitriol), which may also be given preoperatively in cases of severe hypercalcaemia. A concomitant oral calcium supplementation using calcium carbonate as medication of choice is contentious. Due to a potential relapse after successful excision of the affected parathyroid gland in PH, the serum calcium level should be monitored periodically.

Stepwise CaSR, AP2S1, and GNA11 sequencing in patients with suspected familial hypocalciuric hypercalcemia

PURPOSE

Patients with familial hyperparathyroidism and low urinary calcium excretion may have familial hypocalciuric hypercalcemia (FHH) with mutations in one of three genes: the calcium-sensing receptor (CaSR) defining FHH-type 1, the adaptor-related protein complex 2 (AP2S1) related to FHH-type 3 or the G-protein subunit alpha11 (GNA11) associated with FHH-type 2. We aimed to evaluate the presence of mutations in these genes and to identify phenotypic specificities and differences in these patients.

SUBJECTS AND METHODS

Selected patients were recruited for genetic evaluation. After informed consent was signed, blood for DNA extraction was obtained and genetic sequencing of CaSR was done. In negative cases, we further performed sequencing of AP2S1 and GNA11.

RESULTS

A total of 10 index cases were recruited. CaSR sequencing yielded three missense heterozygous mutations (30%): c.554G > A (p.I32V) previously characterized by our team, c.1394 G > A (p.R465Q) and a novel expected disease-causing mutation c.2479 A > C (p.S827R). We identified 2 additional patients (20%) carrying the deleterious recurrent mutation c.44G > T (p.R15L) in the AP2S1 gene. No GNA11 mutation was found. Clinically, patients with AP2S1 mutations had significant cognitive and behavioral disorders, and higher blood calcium and magnesium levels than patients with FHH1.

CONCLUSION

CaSR and AP2S1 sequencing is worthwhile in patients with familial hyperparathyroidism and phenotype suggesting FHH as it can diagnose up to 50% of cases. GNA11 mutations seem much rarer. Learning disabilities in these patients, associated with higher serum calcium and magnesium levels may suggest the presence of AP2S1 rather than CaSR mutation and may guide the first step in the genetic evaluation.

The coexistence of hypercalcemia and hypoglycemia in a patient with a renal tumor and B cell lymphoma

Paraneoplastic syndromes are a heterogeneous group of malignant diseases caused by events which involve endocrine, immune and metabolic aspects and whose symptoms vary according to the substance produced and the primary tumor. Hypercalcemia is a frequent complication in cancer patients. Prognosis of cancer patients with hypercalcemia is usually poor. A factor called parathyroid hormone related peptide, whose actions are similar to those of the parathyroid hormone, is thought to be the most common cause of malignancy associated hypercalcemia. Non-islet hypoglycemic cell tumor consists of a rare syndrome characterized by the presence of a solid tumor and severe fasting hypoglycemia determined by an insulin-independent pathway. We report a case of a 59-year-old-man with a renal tumor and a T-cell rich large B cell lymphoma who was hospitalized due to severe hypercalcemia and hypoglycemia. The laboratory examination reported hypercalcemia with inhibited PTH and hypoglycemia with inhibited insulin secretion, arriving to the conclusion of tumoral peptide production. He received denosumab and corticoid therapy. The patient died one month later despite initial improvement after medical treatment. While a single paraneoplastic manifestation may be expected in most tumors, the coexistence of two or more of them is rare, except in hepatocellular carcinomas, and it has not yet been described in renal tumors.

Hypercalcemia due to Nasopharyngeal Carcinoma

Hypercalcemia is a rare metabolic disorder associated with hyperparathyroidism, malignancy and various other causes. Although common in adult malignancies, hypercalcemia is rare in pediatrics and purports poor prognosis. Nasopharyngeal carcinoma is rare with no reported hypercalcemic presentation. We present here a case of hypercalcemia in a child of nasopharyngeal carcinoma. A 10 year girl presented with backache for 1 month, epistaxis, cough, chest-pain for 1 week alongwith anorexia and weight loss. Investigations revealed anemia and hypercalcemia (23mg/dl; normal range 9-11 mg/dl) with hyperphosphatemia, normal parathyroid levels. Hypercalcemic crisis was managed with saline, furosemide and bisphosphonate. Computed Tomography of paranasal sinuses revealed mass in right nasal cavity. Endoscopic biopsy disclosed undifferentiated nasopharyngeal carcinoma. The child expired despite supportive measures. Thus, hypercalcemia, though rare, may complicate advanced tumors. NPC, being rare in children, requires high index of suspicion with careful clinicoradiological examination and timely management for better chances of survival.

Acute presentation of a giant intrathyroidal parathyroid adenoma: a case report

BACKGROUND

We report the case of a giant intrathyroidal parathyroid adenoma weighing 59 g in a young woman presenting acutely with severe hypercalcemia requiring correction and adequate preoperative management prior to surgery. Parathyroid adenomas account for 85 % of cases of primary hyperparathyroidism. Those weighing more than 3.5g are classified as giant parathyroid adenomas. There are only 25 cases of parathyroid adenomas weighing over 30g reported in the literature. With the wide availability of biochemical screening tests in Western countries, mildly elevated calcium levels are often discovered incidentally. Our case is unusual for the extreme level of hypercalcemia, the patient's young age, and the weight of the adenoma, particularly in a developed country.

CASE PRESENTATION

A 21-year-old Irish woman presented with a 3-week history of an enlarging right-sided neck mass. There was no dysphagia, stridor, or symptoms of hyperthyroidism or hypercalcemia. On examination, there was a firm painless swelling in the right lobe of her thyroid. Her thyroid function tests were normal. Corrected serum calcium was markedly elevated at 3.96 mmol/L with hypophosphatemia of 0.35 mmol/L. She was treated with bisphosphonates and fluids administered intravenously. Her parathyroid hormone level was over 20 times the upper limit of normal. Ultrasound revealed a solid and cystic nodule in the lower pole of the right lobe of her thyroid. Parathyroid scintigraphy demonstrated a 5×4 cm lesion which concentrated tracer. A right-sided parathyroidectomy, right thyroid lobectomy, and level VI neck dissection were performed. An encapsulated multiloculated solid cystic mass weighing 59 g was removed. There was no definite infiltration of the capsule and MIB1 count was low at 1 % thus the specimen lacked the diagnostic features of carcinoma. On the third postoperative day, hungry bone syndrome developed and calcium replacement administered intravenously was required. At 1-year postoperative, she was weaned off calcium and alfacalcidol. A follow-up ultrasound showed unremarkable residual thyroid.

CONCLUSIONS

Any patient with an isolated hypercalcemia warrants a thorough work-up. Hungry bone syndrome is a potentially avoidable condition; thus the clinician should be highly attuned to the risk of hungry bone syndrome post-parathyroidectomy, which correlates with the weight of the adenoma resected.

Clinical features of Sarcoidosis in Oman: A report from the Middle East region

BACKGROUND

Though clinical features of sarcoidosis follow a similar pattern, some heterogeneity is seen in different ethnic and racial groups.

OBJECTIVES

To describe for the first time the clinical characteristics of sarcoidosis patients in the Sultanate of Oman.

METHODS

The data on all cases of sarcoidosis followed up in the two tertiary hospitals in Oman were retrieved retrospectively.

RESULTS

Of the 92 patients, for representing the ethnic data only Omani patients (n=83) were included. The mean age was 52.90±12.35 years. Majority were females (72.3%, n=60). Cough (n=44, 53.0%), dyspnea (n=39, 47%), arthralgia (n=26, 31.3%) and fatigue (30.1%) were the major symptoms. Arthralgia was reported by 41.7% of the females and 4.3% of the males (p= 0.001). Uveitis was present in 16 (19.3%), erythema nodosum in 8 (9.6%) and hypercalcemia in 13 (15.7%). The radiological stage at presentation was stage 0, 18.7%; I, 28%; II, 17.3%; III, 24% and IV, 12%. Majority (61.4%) of the patients had tissue diagnosis; intra-thoracic site 70.6%. Pulmonary function showed abnormal diffusion in 75%. Sixty eight received treatment, 81.9% took prednisolone. Based on radiograph good outcome (Resolving) was noted in 20.9%, intermediate (Stable) in 73.1% and poor (Progressive) in 6%. Lung function wise, resolving, stable and progressive disease was seen in 31.4%, 40.0% and 28.6% respectively.

CONCLUSION

The clinical picture of the patients with sarcoidosis from Oman was similar to that reported from the rest of the world. Region wise, our patients were older and arthralgia and hypercalcemia were more common. The management of sarcoidosis needs a more organized approach in the country with clear guidelines on monitoring and treatment.

24-hour outpatient ECG as a screening method in patients with primary hyperparathyroidism

PURPOSE

Patients with primary hyperparathyroidism are characterized by increased calcium plasma concentrations, which in turn could have a potential to induce ECG changes, especially shortening of the QT interval. Therefore, the aim of this study was to evaluate, whether the routine 24-hours outpatient ECG monitoring could be used for screening the primary hyperparathyroidism.

METHODS

Totally, 31 patients (mean age, 59.2 ± 12.99 years) with primary hyperparathyroidism were compared to 20 healthy controls. All patients underwent mineral metabolism biochemical evaluation, ultrasound or scintigraphy of the neck, and a 24-hour outpatient ECG. The device detected QT, QTc, and RR intervals during a 24-hour period.

RESULTS

Significantly higher calcium concentrations were confirmed in patients when compared to controls (2.38 ± 0.12 vs 2.92 ± 0.29 mmol/l; p < 0.001). However, no significant differences were found between controls and patients in QT interval and overall heart rate.

CONCLUSION

Although shortening of the QT interval is a common ECG finding in patients with hyperparathyroidism, it seems that 24-hour outpatient ECG is not suitable for primary hyperparathyroidism screening (Tab. 2, Fig. 4, Ref. 28).

Small-Cell Carcinoma of the Ovary of Hypercalcemic Type (Malignant Rhabdoid Tumor of the Ovary): A Review with Recent Developments on Pathogenesis

Small-cell carcinoma of the ovary of hypercalcemic type (SCCOHT) is a highly malignant and aggressive tumor and is the most common undifferentiated ovarian malignancy to occur in women younger than 40. SCCOHT is characterized by deleterious germline or somatic mutations in SMARCA4. Given the striking morphologic and molecular similarities between SCCOHT and atypical teratoid/malignant rhabdoid tumor, we propose this should be reflected in a nomenclature change and that SCCOHT be renamed malignant rhabdoid tumor of the ovary. SMARCA4 (BRG1) immunohistochemistry is useful in diagnosis because there is loss of nuclear immunoreactivity in SCCOHT but retention of staining in mimics.

Abnormal Diurnal Patterns of Parathyroid Hormone are Associated with Sustained Mild Hypercalcemia in Non-Dialyzed Chronic Kidney Disease

BACKGROUND

Plasma PTH levels are normally high during the night and early morning and lowest at approximately 10 am (the PTH circadian rhythm). Our objective was to examine the relationship between the PTH circadian rhythm and calcium-phosphorus metabolism in non-dialyzed, chronic kidney disease (CKD) patients.

METHODS

The characteristics of twenty-eight subjects comprised: male, 23; diabetic patients, 16; mean age, 71.1 +/- 10.5 years; mean eGFR, 18.3 +/- 8.1 mL/min/1.73 m2. Under a protein-restricted diet, plasma intact PTH (iPTH) was measured at 7 am (iPTH7), 10 am (iPTH10), and 10 pm (iPTH22). Serum concentrations of calcium (Ca), phosphate (Pi), 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D (1,25[OH]2D), and fibroblast growth factor (FGF)-23 were measured at 7 am. A normal iPTH rhythm was defined as when both iPTH7 and iPTH22 exceeded iPTH10. When iPTH10 was equal to, or exceeded either iPTH7 or iPTH22, or both, the rhythm was considered abnormal.

RESULTS

Median levels of iPTH7, iPTH10, and iPTH22 were 92.5 [IQR: 60.8-152.01, 85.5 [61.0-144.5], and 95.5 164.3-160.5] pg/mL, respectively. Sixteen subjects showed an abnormal iPTH rhythm. There was no significant difference between groups in age, eGFR, iPTH7, iPTH10, iPTH22, Pi, 25-OH1D, 1,25(OH)2D, or FGF-23. However, the abnormal group showed significantly higher mean levels of corrected Ca as compared to the normal group (9.50 +/- 0.42 vs. 9.18 +/- 0.28; p = 0.032).

CONCLUSIONS

Abnormal diurnal patterns of PTH are associated with sustained mild hypercalcemia in nondialyzed chronic kidney disease patients. This abnormal rhythm was not associated with Pi or FGF-23, and this may be an independent risk factor for CKD-mineral and bone disorder.

Life-Threatening Hypercalcemia Revealing Diffuse and Isolated Acute Sarcoid-Like Myositis: A New Entity? (A Case-Series)

Up to 50% patients with sarcoidosis display extra-pulmonary disease. However, initial and isolated (ie, without lung disease) acute muscular involvement associated with pseudo-malignant hypercalcemia is very uncommon. We report on 3 cases of life-threatening hypercalcemia revealing florid and isolated acute sarcoid-like myositis.All patients complained of fatigue, progressive general muscle weakness, and weight loss. Laboratory tests showed a severe life-threatening hypercalcemia (>3.4 mmol/L). Hypercalcemia was associated with increased serum level of 1,25-(OH)2 vitamin D and complicated with acute renal failure. One patient displayed acute pancreatitis due to hypercalcemia.In all cases, PET-scan, performed for malignancy screening, incidentally revealed an intense, diffuse, and isolated muscular fluorodeoxyglucose (FDG) uptake consistent with diffuse non-necrotizing giant cells granulomatous myositis demonstrated by muscle biopsy. Of note, creatine phosphokinase blood level was normal in all cases. No patients displayed the usual thoracic features of sarcoidosis.All patients were treated with high dose steroids and achieved rapid, complete, and sustained remission. A review of English and French publications in Medline revealed 5 similar published cases.Steroid-sensitive acute sarcoid-like myositis causing high calcitriol levels and life-threatening hypercalcemia should be recognized as a separate entity.

[When should the nephrologist be called in the emergency room?]

Nephrology emergencies are not the most frequent in the emergency room but they often generate some diagnostic and therapeutic problems. Most common renal emergencies are due most often to acute renal failure whatever the cause, electrolytes disturbances, hypertensive crisis and less frequently intoxications or acute decompensation of chronic kidney diseases. The goal of this paper is to review some of these clinical situations both in the diagnostic and therapeutic perspective but essentially to discuss when the nephrologist should be called in the emergency room so that the coordination of care is optimal for the patients.

Idiopathic infantile hypercalcemia: case report and review of the literature

The widespread use of supplemental vitamin D has dramatically reduced the incidence of rickets. While generally considered a safe practice, there is potential for toxicity in patients with idiopathic infantile hypercalcemia (IIH). Inadequate 24-hydroxylase-enzyme activity renders these individuals unable to degrade active vitamin D, resulting in hypercalcemia due to increased intestinal calcium absorption, decreased renal calcium excretion, and increased osteoclastic bone activity. Clinicians should be aware that even therapeutic doses of vitamin D can prove harmful for patients with CYP24A1 mutations. Studies have also demonstrated a link between inadequate 24-hydroxylase activity and nephrocalcinosis, renal insufficiency, and calcium containing kidney stones, further emphasizing the importance of early recognition of this disease and judicious use of vitamin D. We present a case with an interesting diagnostic algorithm used to diagnose IIH when given an incomplete history and subsequently review the existing literature on the subject.

New Predictive Equations for Serum Ionized Calcium in Hospitalized Patients

OBJECTIVE

To study a new and easy way to calculate equations to predict ionized calcium (Ca2+) for adult hospitalized patients with the usual laboratory and clinical parameters.

SUBJECTS AND METHODS

This retrospective observational study was conducted in a third-level university hospital. An initial learning cohort (cohort L: 269 patients) was selected to derive the new equations. These equations were tested in a validation of another cohort (cohort V: 146 patients). Patients selected were hospitalized adults who had simultaneous determinations of Ca2+ and serum total calcium (CaTot). They were classified using their estimated glomerular filtration rate (GFRe) into normal function, moderate and severe kidney dysfunction. Demographic and biochemical parameters, in addition to comorbidities, were collected from hospital databases. Nine published equations to predict Ca2+ and 2 widely used equations to predict corrected CaTot were also selected to be compared to newer equations for accuracy in detecting serum calcium alterations. New equations were derived by a multiple linear-regression analysis from patients in cohort L.

RESULTS

Three equations were derived containing the CaTot square root as the main independent variable. Equation 1: Ca2+ = 0.815 × CaTot(0.5). Equation 2: Ca2+ = 0.826 × CaTot(0.5) - 0.023 × renal function. Equation 3: Ca2+ = 0.813 × CaTot(0.5) - 0.006 × albumin(0.75) + 0.079. These equations performed better than published equations to predict Ca2+ when their error measures were analyzed in cohort V, even in special populations such as critically ill and very old patients.

CONCLUSIONS

Three new equations predicting Ca2+ were derived requiring easily available clinical and laboratory parameters. They could be valuable in predicting hypocalcemia but are of limited use in hypercalcemia.

Parathyroidectomy in asymptomatic primary hyperparathyroidism reduces carotid intima-media thickness and arterial stiffness

OBJECTIVE

Although an International Workshop has suggested that cardiovascular assessment in asymptomatic primary hyperparathyroidism (PHPT) patients is not necessary, improvements in risk factors of subclinical atherosclerosis have been shown following parathyroidectomy. The objectives of this study were to determine whether parathyroidectomy in asymptomatic PHPT patients causes any change in carotid intima-media thickness (CIMT), arterial stiffness [pulse wave velocity (PWV)] and soluble CD40 ligand (sCD40L) levels.

DESIGN

Prospective study evaluating female patients diagnosed with asymptomatic PHPT in a single centre over a 6-month period.

PATIENTS

A total of 48 subjects were included: 17 hypercalcaemic (HC, mean age: 51 ± 8 years, Ca: 2·73 ± 0·17 mmol/l) and 16 normocalcaemic (NC, mean age: 58 ± 7 years, Ca: 2·30 ± 0·10 mmol/l) PHPT patients, and 15 healthy controls (mean age: 52 ± 4 years, Ca: 2·27 ± 0·07 mmol/l).

MEASUREMENTS

Biochemical tests, CIMT, PWV and sCD40L levels were compared at baseline and 6 months after parathyroidectomy (PTx).

RESULTS

At baseline, CIMT and PWV values in the HC and NC patients were higher than in the control group. While there was a significant reduction in CIMT (601 ± 91 μm vs 541 ± 65 μm, P = 0·006) and PWV (9·6 ± 1·8 vs 8·4 ± 1·5 m/s, P = 0·000) in the hypercalcaemic group at the end of the 6th month after PTx, no change was observed in normocalcaemic group (P = 0·686 and P = 0·196 respectively). No differences were observed in sCD40L levels between patient and control groups or between baseline and 6 months in patients undergoing parathyroidectomy.

CONCLUSION

Parathyroidectomy leads to an improvement in the structural and functional impairment associated with atherosclerosis in the vascular wall in asymptomatic hypercalcaemic PHPT patients.

Presentation of parathyroid adenoma with genu valgum and thoracic deformities

Parathyroid adenoma is the main cause of primary hyperparathyroidism. It is usually asymptomatic and occurs more commonly in adults. It presents with raised parathormone (PTH) and Ca+ levels in serum. Its presentation in adolescence is rare. We report one such incidence of a 14 years old girl who presented with bone pains short stature, and generalized muscle wasting. She was found to have genu valgum at the knee joint, pectus carniatum, scoliosis and cystic changes in pelvis and calvarium. Biochemical investigations and parathyroid Tc-99mMIBI scan confirmed the diagnosis of a parathyroid adenoma. The gland was removed by parathyroidectomy. Till date 12 such cases are reported and none had thoracic, vertebral or calvarium involvement.

[Hypercalcemia, symptoms, differential diagnostics and treatment, or importance of calcium investigation]

The concentration of calcium is carefully maintained under physiological conditions with parathormone, calcitonin and 1,25-dihydroxyvitamin D at appropriate levels. There are multiple causes that may bring about increased concentrations of calcium which exceed physiological values. Increased production of parathormone in parathyroid glands is only one of the possible causes. Malignant diseases are a very frequent cause of hypercalcemia, due to their creating mediators which stimulate osteoclasts and thereby osteolysis. A less frequent cause is represented by granulomatous processes, a typical example of which is sarcoidosis, whose cells increasingly (independently of parathormone) hydroxylate 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D. However there are also hereditary forms of hypercalcemia. One of the causes of the hereditary form of hypercalcemia is mutations of the calcium sensing receptor. In order to locate the adenoma of parathyroid glands, essential apart from sonographic imaging is scintigraphy 99mTc-methoxyisobutylisonitrile (MIBI) and even more exact is PET-CT examination with a radio-pharmaceutical 18F-fluorocholine. PET-CT examinations are beneficial with regard to detecting a malignant cause of hypercalcemia in until then undetected malignancy or an undetected granulomatous process. The essential treatment procedures for malignant hypercalcemia include appropriate hydratation of ionic solutions without calcium, administering of bisphosphonates or denosumab. The text describes in detail the symptoms of hypercalcemia and diagnostics of causes of hypercalcemia.

KEY WORDS

bisphosphonates - cinacalcet - denosumab - granulomatous diseases - hereditary hypercalcemia - hypercalcemia - hypercalciuria - hyperparathyreosis - calcimimetics - calcitonin - multiple myeloma - malignant hypercalcemia - parathormone - sarcoidosis - 1,25-dihydroxyvitamin D.

[Hypo and hypercalcemia: from diagnosis to treatment]

The hypercalcemia is defined as a blood calcium range above 2.6 mmol/l. Its prevalence is variable in different studies and it is comprised between 2 and 8/1000 in the general population. The primary hyperparathyroidism (PHP) and cancers are both responsible for about 80 per cent to 90 per cent of causes of hypercalcemia1. The PHP is the first ambulatory cause of hypercalcemia. Contrarily to this, the neoplastic etiology is mainly seen in the hospital settings. The other causes of the hypercalcemia are vitamin D overdose, secondary hypercalcemia due to medications intake and familial hypocalciuric hypercalcemia which will be discussed in this article. The hypocalcemia is defined as a blood calcium range underneath 2.2 mmol/l. The most common etiologies are the postoperative hypopara-thyroidism as a complication of approximatively 1.5 % of thyroidectomies2, the vitamin D deficiency and terminal chronic kidney failure. The other rare causes such as autoimmune hypoparathyroidism, parathyroid agenesis, pseudoparathyroidism and hypomagnesemia will be discussed in this article.

EXPANSION OF THE SHORT SYNDROME PHENOTYPE IN AN ADULT PATIENT WITH UNILATERAL BASAL GANGLIA CALCIFICATION

SHORT syndrome is a rare autosomal dominant disorder whose acronym stands for short stature, hyperextensibility of joints and/or hernias, ocular depression, Rieger anomaly, and teething delay. Common clinical features include intrauterine and postnatal growth restriction, lipoatrophy, characteristic facial gestalt, anterior chamber defects and insulin resistance/diabetes. To date, the coexistence of SHORT syndrome and unilateral basal ganglia calcification has not been reported. Here, we describe a 27-year-old woman bom to healthy first-cousin Mexican parents who exhibited the SHORT syndrome phenotype and unilateral basal ganglia calcification. The current observation provides additional knowledge of the spectrum of anomalies that can occur in SHORT syndrome and further illustrates the clinical variability of this disorder. Therefore, basal ganglia calcification and other brain abnormalities should be specifically looked for in all affected patients in order to provide appropriate medical management and genetic counseling.

Retinal Detachment and Symptomatic Hypercalcemia in a Patient with Sarcoidosis: Unusual Presentation of a Granulomatous Disease

Sarcoidosisis amultisystemic granulomatous disease, potentially affecting any organ system of the body. Calcium metabolism disturbances occur in up to 20% of patients, of which hypercalciuria and asymptomatic hypercalcemia are most common. Ocular sarcoid typically presents with anterior chamber manifestations such as uveitis, iritis, and iridocyclitis, but can involve posterior chamber as well. We describe herein a unique presentation of sarcoidosis with retinal detachment and symptomatic hypercalcemia as its first manifestation. Prompt therapy with steroids is indicated in these cases, and an immediate ophthalmology referral cannot be overemphasized.

A Case of Solitary Kidney Atrophy Due to Primary Hyperparathyroidism: A Case Report

Although primary hyperparathyroidism (PHPT) is asymptomatic in most patients, its main clinical manifestation is nephrolithiasis. In general, hypercalcemia would lead to unilateral renal stones, which may become bilateral over time. We present a rare case of a large unilateral asymptomatic ureteral stone in a patient with hypercalcemia secondary to PHPT, which eventually led to renal atrophy.The diagnosis of PHPT should be considered in patients with hypercalcemia and renal stones, as asymptomatic PHPT may result in a devastating renal outcome.

Idiopathic Infantile Hypercalcemia, Presenting in Adulthood--No Longer Idiopathic Nor Infantile: Two Case Reports and Review

We present two unrelated cases of young adults with hypercalcemia, hypercalciuria, and nephrocalcinosis. Both had suppressed intact parathyroid hormone levels and high 1,25 vitamin D levels after only brief, low-dose, over-the-counter vitamin supplementation. Neither had evidence of a granulomatous disorder. Their presentation mimicked that of 1,25 hydroxy vitamin D intoxication. In both patients, the diagnosis of idiopathic infantile hypercalcemia was confirmed with immeasurably low 24,25 vitamin D levels. Both were found to have a loss-of-function mutation in the CYP24A1 gene, which encodes the vitamin D-metabolizing enzyme 25-hydroxyvitamin D 24-hydroxylase.

Management of hypercalcemia

Hypercalcemia is a common metabolic condition encountered in both inpatient and outpatient settings. Physicians can more successfully diagnose and treat patients when armed with a thorough understanding of normal calcium metabolism and how it can be disrupted by disease. In virtually all cases, the cause of an elevated serum calcium concentration can be quickly ascertained through the use of selected diagnostic tests. Effective treatment options can then be implemented.

Follicular lymphoma presenting with hypercalcaemia: an unusual mechanism of hypercalcaemia

Hypercalcaemia is a frequent finding in patients with cancer. In up to 30% of malignancies, the disease course is complicated with hypercalcaemia. For hospitalized patients, cancer is the most common cause of hypercalcaemia. In normal physiological circumstances, the ionized calcium is kept in check by the influence of two important hormones, parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH)2D). However, cancer can misbalance the calcium homeostasis by generating certain humoural mediators. Overproduction of parathyroid hormone-related peptide (PTH-rp), intact PTH, 1,25(OH)2D, and cytokines all cause hypercalcaemia. Hypercalcaemia is frequent in certain haematological cancers such as multiple myeloma and aggressive lymphomas. But hypercalcaemia is rare in patients with indolent lymphomas such follicular lymphoma. This case illustrates as a first to our knowledge the involvement of cytokines and chemokines in the pathophysiology of lymphoma-related hypercalcaemia. A pathophysiological mechanism is offered based upon the current understanding of cytokines and chemokines related to follicular lymphoma.

[Hypercalcemia-induced pancreatitis in a patient with parathyroid adenoma and thyroid papillary carcinoma]

Acute pancreatitis due to hypercalcemia secondary to primary hyperparathyroidism is a rare aetiology. We present a female patient with pancreatitis; with prior cholecystectomy, no alcohol usage or dyslipidemia. Laboratory studies showed, serum calcium 17.93 mg/dL and iPTH 441 pg/ml. Neck CT showed multinodular goiter and a parathyroid nodule. The patient underwent surgery after which serum Ca and PTH decreased. Biopsy showed follicular variant papillary thyroid carcinoma. This report discusses possible theories of association between parathyroid adenoma and hypercalcemic pancreatitis and describes the association with follicular variant papillary thyroid carcinoma, not previously described.

Late-onset hypercalcemia in Williams-Beuren syndrome: importance of early and frequent screening and intervention

Williams-Beuren syndrome (WBS) affects multiple systems and has a known association with infantile hypercalcemia that is typically mild and transient. We report a 12-month-old female previously diagnosed with WBS by a chromosomal microarray, who was admitted for failure to thrive. Upon evaluation, serum calcium of 19.0 mg/dL (4.75 mmol/L) (normal 9-11 mg/dL, SI: 2.25-2.75 mmol/L) and serum ionized calcium of 2.33 mmol/L (normal 1.22-1.37 mmol/L) were revealed. Her hypercalcemia correlated with symptoms of irritability, poor feeding, mild hypotonia, and constipation, which were increasingly present for 6 months prior to admission. This calcium level is one of the highest reported in association with WBS. Additionally, while hypercalcemia associated with WBS typically resolves by the first year, this case represents a later presentation as compared to other reports. The patient initially responded to conservative treatment with intravenous fluids administration, loop diuretic therapy, and dietary calcium restriction. However, she subsequently had rebound hypercalcemia 5 weeks after treatment and received one dose of intravenous bisphosphonate with subsequent resolution of her hypercalcemia. Our report highlights the importance of screening, early management, and recognition of late presentation hypercalcemia in the setting of WBS.

Approach to the Child with Hypercalcaemia

Hypercalcaemia is rare in children. In adulthood, the causes are most frequently malignancy and primary hyperparathyroidism. In children, however, the aetiologies are diverse and age specific, and many have an underlying genetic basis. Hypercalcaemia is a serious condition that frequently leads to end-organ damage. In order to provide the most appropriate treatment, a key part of the management pathway is to establish the correct diagnosis promptly. When considering a practical approach to hypercalcaemia in children, it is helpful to consider the causes of hypercalcaemia according to the accompanying levels of parathyroid hormone (PTH), indicating whether the causes are PTH dependent or PTH independent. This chapter reviews the recent advances in this area and presents a practical approach to the investigation and subsequent management of this condition.

[Hypercalcemia and acute renal failure: a case report of vitamin D intoxication]

Vitamin D (VTD) deficiency has become a topical issue leading to screening with frequent supplementation. The latter can be dangerous and exceptionally causes overdoses. We report the case of a 20 year old patient with abdominal pain in the setting of hypercalcemia due to intoxication by VTD. This case offers the opportunity to describe the differential diagnosis of hypercalcemia and to brownse through the literature in search of clinical practice recommendations for VTD supplementation.