Hypercalcemia due to excess 1,25-dihydroxyvitamin D in Crohn's disease

Risk factors for developing hyperoxaluria in children with Crohn's disease

BACKGROUND

For the purpose of a better understanding of enteric hyperoxaluria in Crohn's disease (CD) in children and adolescents, we investigated the occurrence and risk factors for development of hyperoxaluria in those patients.

METHODS

Forty-five children with CD and another 45 controls were involved in this cross-sectional study. Urine samples were collected for measurement of spot urine calcium/creatinine (Ur Ca/Cr), oxalate/creatinine (Ur Ox/Cr), and citrate/creatinine (Ur Citr/Cr) ratios. Fecal samples were also collected to detect the oxalyl-CoA decarboxylase of Oxalobacter formigenes by PCR. Patients were classified into 2 groups: group A (with hyperoxaluria) and group B (with normal urine oxalate excretion). The disease extent was assessed, and the activity index was calculated.

RESULTS

According to the activity index, 30 patients (66.7%) had mild disease and 13 patients (28.9%) had moderate disease. There was no significant difference in Ur Ox/Cr ratio regarding the disease activity index. O. formigenes was not detected in 91% of patients in group A while it was detected in all patients in group B (p < 0.001). By using logistic regression analysis, the overall model was statistically significant when compared to the null model, (χ² (7) = 52.19, p < 0.001), steatorrhea (p = 0.004), frequent stools (p = 0.009), and O. formigenes (p < 0.001).

CONCLUSION

Lack of intestinal colonization with O. formigenes, steatorrhea, and frequent stools are the main risk factors for development of enteric hyperoxaluria in CD patients. Identifying risk factors facilitates proper disease management in future studies. A higher resolution version of the Graphical abstract is available as Supplementary information.

Rare Causes of Hypercalcemia: 2021 Update

CONTEXT

Primary hyperparathyroidism and malignancy are the etiologies in 90% of cases of hypercalcemia. When these entities are not the etiology of hypercalcemia, uncommon conditions need to be considered. In 2005, Jacobs and Bilezikian published a clinical review of rare causes of hypercalcemia, focusing on mechanisms and pathophysiology. This review is an updated synopsis of rare causes of hypercalcemia, extending the observations of the original article.

EVIDENCE ACQUISITION

Articles reporting rare associations between hypercalcemia and unusual conditions were identified through a comprehensive extensive PubMed-based search using the search terms "hypercalcemia" and "etiology," as well as examining the references in the identified case reports. We categorized the reports by adults vs pediatric and further categorized the adult reports based on etiology. Some included reports lacked definitive assessment of etiology and are reported as unknown mechanism with discussion of likely etiology.

EVIDENCE SYNTHESIS

There is a growing understanding of the breadth of unusual causes of hypercalcemia. When the cause of hypercalcemia is elusive, a focus on mechanism and review of prior reported cases is key to successful determination of the etiology.

CONCLUSIONS

The ever-expanding reports of patients with rare and even unknown mechanisms of hypercalcemia illustrate the need for continued investigation into the complexities of human calcium metabolism.

Understanding the molecular association between hyperkalemia and lung squamous cell carcinomas

Background

Previous studies indicated a strong association between hyperkalemia and lung squamous cell carcinomas (LSCC). However, the underlying mechanism is not fully understood so far.

Methods

Literature-based data mining was conducted to identify genes, molecule, and cell processes linked to both hyperkalemia and LSCC. Pathway analysis was performed to explore the interactive network, common-target network, and common-regulator network for both disorders. Then, a mega-analysis using 11 independent LSCC RNA expression datasets (358 LSCCs and 278 healthy controls) was performed to test the hypothesis that genes influencing hyperkalemia may also play roles in LSCC.

Results

There was a significant overlap between the genes implicated with both diseases (20 genes, p-value = 4.98e-15), which counts for 16% of all hyperkalemia genes (125 genes). Network analysis identified 12 molecules as common targets for hyperkalemia and LSCC, and 19 molecules as common regulators. Moreover, 19 molecules were identified within an interactive network, through which hyperkalemia and LSCC could exert influence on each other. In addition, meta-analysis identified one hyperkalemia promoter, SPP1, as a novel contributor for LSCC (LFC = 2.64; p-value = 2.81e-6). MLR analysis suggests geographical region as an influential factor for the expression levels of SPP1 in LSCC patients (p value = 0.036, 0.054).

Conclusion

Our results showed that there was a common molecular basis for the pathology of both hyperkalemia and LSCC, and that genes promoting hyperkalemia might also play roles in the development of LSCC. However, this study did not suggest hypercalcemia as a casual factor for LSCC.

GRANULOMATOUS DISEASE OF UNUSUAL SITES CAUSING HYPERCALCEMIA: TWO CASE REPORTS

Objective

Hypercalcemia with suppressed parathyroid hormone (PTH) levels is mostly due to granulomatous disease (GD) or neoplastic disease. In GD, autonomous activity of extra-renal 1α-hydroxylase enzyme is usually the underlying cause. We describe a pair of cases where hypercalcemia resulted from GD of unusual sites posing significant diagnostic challenges.

Methods

We describe 2 cases of PTH-independent hypercalcemia due to GD of the prostate gland and the stomach.

Results

Both cases presented with marked hypercalcemia and suppressed PTH levels. Case 1 is an elderly male who presented with marked symptomatic hypercalcemia on multiple occasions. Investigations revealed elevated levels of 1,25-dihydroxyvitamin D3 and prostate-specific antigen but normal PTH-related protein. Transrectal biopsy of the prostate gland confirmed the presence of chronic granulomatous prostatitis. The patient responded very well to steroids which entirely normalized his calcium level. Case 2 is a male who presented similarly with significant hypercalcemia but had upper gastrointestinal symptoms and anemia at onset. Endoscopy and biopsy established the presence of granulomatous gastritis likely due to Crohn disease which responded to steroids resulting in normalization of calcium levels within a short span of time.

Conclusion

While the majority of PTH-independent hypercalcemia cases are due to GDs of lymph nodes or malignancy, our cases indicate that in uncertain cases, granulomatous processes involving unusual sites should be considered in the evaluation of hypercalcemia with suppressed PTH.

Hypercalcaemia due to isolated elevation of 1,25-dihydroxyvitamin D in patients with Crohn’s disease

Crohn’s disease is frequently associated with hypocalcaemia following poor calcium intake and decreased intestinal calcium absorption due to malabsorption-related vitamin D deficiency. Severe hypercalcaemia found in Crohn’s disease is an unusual clinical entity. We chronicle here the case of a patient who developed hypercalcaemia with elevated 1,25-dihydroxyvitamin D during Crohn’s disease exacerbation. Furthermore, we conducted a systematic literature search of MEDLINE, Cochrane, Embase, and Scopus databases regarding 1,25-dihydroxyvitamin D-associated hypercalcaemia in Crohn’s disease. A comprehensive review of the search results yielded a total of five case reports only. The data on patient demographics, clinical features, serum calcium levels, Crohn’s disease activity site, treatment strategy, hypercalcaemia resolution time and outcomes were collected and analysed. This paper illustrates that Crohn’s disease should be added to the list of granulomatous disorders responsible for 1,25-dihydroxyvitamin D-mediated hypercalcaemia. Physicians should maintain a high index of clinical suspicion for this potential complication for prompt management.

Hypercalcemic Disorders in Children

Hypercalcemia is defined as a serum calcium concentration that is greater than two standard deviations above the normal mean, which in children may vary with age and sex, reflecting changes in the normal physiology at each developmental stage. Hypercalcemic disorders in children may present with hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, and seizures. In severe cases renal failure, pancreatitis and reduced consciousness may also occur and older children and adolescents may present with psychiatric symptoms. The causes of hypercalcemia in children can be classified as parathyroid hormone (PTH)-dependent or PTH-independent, and may be congenital or acquired. PTH-independent hypercalcemia, ie, hypercalcemia associated with a suppressed PTH, is commoner in children than PTH-dependent hypercalcemia. Acquired causes of PTH-independent hypercalcemia in children include hypervitaminosis; granulomatous disorders, and endocrinopathies. Congenital syndromes associated with PTH-independent hypercalcemia include idiopathic infantile hypercalcemia (IIH), William's syndrome, and inborn errors of metabolism. PTH-dependent hypercalcemia is usually caused by parathyroid tumors, which may give rise to primary hyperparathyroidism (PHPT) or tertiary hyperparathyroidism, which usually arises in association with chronic renal failure and in the treatment of hypophosphatemic rickets. Acquired causes of PTH-dependent hypercalcemia in neonates include maternal hypocalcemia and extracorporeal membrane oxygenation. PHPT usually occurs as an isolated nonsyndromic and nonhereditary endocrinopathy, but may also occur as a hereditary hypercalcemic disorder such as familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, and familial isolated primary hyperparathyroidism, and less commonly, as part of inherited complex syndromic disorders such as multiple endocrine neoplasia (MEN). Advances in identifying the genetic causes have resulted in increased understanding of the underlying biological pathways and improvements in diagnosis. The management of symptomatic hypercalcemia includes interventions such as fluids, antiresorptive medications, and parathyroid surgery. This article presents a clinical, biochemical, and genetic approach to investigating the causes of pediatric hypercalcemia. © 2017 American Society for Bone and Mineral Research.

[Inflammation of the parathyroid glands]

Inflammation of the parathyroid glands is rare when compared to other endocrine organs. This leads to the use of descriptive terms as well as the lack of a generally accepted classification for inflammatory disorders of the parathyroid glands. This review article proposes that parathyroid inflammation be subdivided morphologically into (a) non-specific lymphocytic infiltration, which is more an expression of damage to small vessels, due to e. g. severe systemic inflammation or myocardial infarction, (b) autoimmunogenic lymphocytic parathyroiditis, (c) nonimmunogenic inflammation caused by granulomatous diseases or infections and (d) invasive sclerosing (peri) parathyroiditis. As only parathyroid glands removed due to hyperparathyroidism and normal parathyroid glands incidentally removed during thyroid surgery are seen almost exclusively in routine histopathology, virtually no information about the morphological correlate of hypoparathyroidism is available.

Vitamin D-Mediated Hypercalcemia: Mechanisms, Diagnosis, and Treatment

Hypercalcemia occurs in up to 4% of the population in association with malignancy, primary hyperparathyroidism, ingestion of excessive calcium and/or vitamin D, ectopic production of 1,25-dihydroxyvitamin D [1,25(OH)₂D], and impaired degradation of 1,25(OH)₂D. The ingestion of excessive amounts of vitamin D₃ (or vitamin D₂) results in hypercalcemia and hypercalciuria due to the formation of supraphysiological amounts of 25-hydroxyvitamin D [25(OH)D] that bind to the vitamin D receptor, albeit with lower affinity than the active form of the vitamin, 1,25(OH)₂D, and the formation of 5,6-trans 25(OH)D, which binds to the vitamin D receptor more tightly than 25(OH)D. In patients with granulomatous disease such as sarcoidosis or tuberculosis and tumors such as lymphomas, hypercalcemia occurs as a result of the activity of ectopic 25(OH)D-1-hydroxylase (CYP27B1) expressed in macrophages or tumor cells and the formation of excessive amounts of 1,25(OH)₂D. Recent work has identified a novel cause of non-PTH-mediated hypercalcemia that occurs when the degradation of 1,25(OH)₂D is impaired as a result of mutations of the 1,25(OH)₂D-24-hydroxylase cytochrome P450 (CYP24A1). Patients with biallelic and, in some instances, monoallelic mutations of the CYP24A1 gene have elevated serum calcium concentrations associated with elevated serum 1,25(OH)₂D, suppressed PTH concentrations, hypercalciuria, nephrocalcinosis, nephrolithiasis, and on occasion, reduced bone density. Of interest, first-time calcium renal stone formers have elevated 1,25(OH)₂D and evidence of impaired 24-hydroxylase-mediated 1,25(OH)₂D degradation. We will describe the biochemical processes associated with the synthesis and degradation of various vitamin D metabolites, the clinical features of the vitamin D-mediated hypercalcemia, their biochemical diagnosis, and treatment.

Oral vitamin D3 supplementation reduces monocyte-derived dendritic cell maturation and cytokine production in Crohn's disease patients

BACKGROUND

Low serum vitamin D levels may provoke or aggravate Crohn's disease (CrD). Vitamin D3 is a well-known immune modulator that affects immune functions in vitro and may prevent CrD flares. Dendritic cells (DC) are key mediators of vitamin D3 effects. In this study, we describe changes in monocyte-derived DC (mo-DC) maturation marker expression and cytokine production following 26 weeks of oral vitamin D3 supplementation in CrD patients.

METHODS

Ten CrD patients who had increased serum 25-hydroxy vitamin D levels after oral vitamin D3 and calcium treatment and ten seasonally matched placebo-treated patients were selected for this study. Mo-DC were generated before and after the 26 weeks and induced to mature upon lipopolysaccharide (LPS) stimulation. Maturation marker expression and cytokine production were analysed. Mo-DC function was analysed in a mixed leucocyte reaction (MLR).

RESULTS

Compared with baseline values, LPS-matured mo-DC exhibited reduced expression of CD80 and reduced production of the cytokines IL-10, IL-1β, and IL-6 following 26 weeks of oral vitamin D3 supplementation. Mo-DC performance in an allogeneic MLR was unchanged after vitamin D3 supplementation. Treatment with the placebo did not affect maturation markers, cytokine production, or the MLR.

CONCLUSIONS

Vitamin D3 treatment in CrD patients led to hypo-responsive LPS-stimulated mo-DC. This finding indicates that vitamin D3 levels have an impact on the monocytic precursors of mo-DC in vivo and may explain the positive effects of vitamin D3 supplementation on CrD patients. Alternatively, CrD patients with high serum vitamin D3 levels may represent a subgroup with low disease activity.

Rare causes of calcitriol-mediated hypercalcemia: a case report and literature review

CONTEXT

Calcitriol-mediated hypercalcemia resulting from elevated extrarenal 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-hydroxylase) activity has not previously been described in giant cell polymyositis.

CASE

We report an unusual case of hypercalcemia due to disseminated granulomatous disease in a 62-yr-old woman with profound proximal muscle weakness and weight loss. She was initially diagnosed with vitamin D deficiency myopathy with a low serum 25-hydroxyvitamin D; serum calcium at this time was low-normal. Vitamin D(3) 3000 IU daily was prescribed. One month later, blood work showed new hypercalcemia and hypercalciuria with normalized 25-hydroxyvitamin D. 1,25-dihydroxyvitamin D was high-normal, despite a suppressed PTH, undetectable PTHrP, and essentially normal renal function. Her hypercalcemia resolved, and her strength improved only after prednisone was added to bisphosphonate therapy. Two weeks later, she died from acute congestive heart failure.

METHODS AND RESULTS

Autopsy revealed a disseminated giant cell myositis affecting skeletal, cardiac, and gastrointestinal smooth muscle. Immunohistochemistry localized 1alpha-hydroxylase to the inflammatory infiltrates in skeletal and cardiac muscle.

EVIDENCE

A review of English publications in Medline and Embase, including a reference search of retrieved articles, revealed that calcitriol-mediated hypercalcemia has been described in over 30 conditions, most of which are granulomatous in nature, ranging from inflammatory conditions and foreign body exposures to infections and neoplasms.

CONCLUSIONS

Hypercalcemia resulting from autonomous 1alpha-hydroxylase activity may be unmasked by low-dose vitamin D supplementation and should not be excluded from the differential diagnosis of nonparathyroid causes if the serum calcitriol is inappropriately normal, rather than frankly elevated.

Addressing vitamin D deficiency in Canada: a public health innovation whose time has come

There is disturbing evidence of widespread vitamin D deficiency in many population groups, particularly within nations at high latitude. Numerous recent studies in the scientific literature associate vitamin D deficiency with a colossal increase in morbidity and mortality. Since Canada is at higher latitude, this review assesses the vitamin D status within the Canadian population. This review was prepared by assessing available medical and scientific literature from Medline, as well as by reviewing several books and conference proceedings. A standard 25(OH)D level of 75-80nmol/l or more was used to indicate vitamin D sufficiency. Between 70% and 97% of Canadians demonstrate vitamin D insufficiency. Furthermore, studies assessing 25(OH)D levels of vitamin D at 25-40nmol/l reveal that many Canadians have profoundly deficient levels. Repletion of vitamin D3 with 2000IU/day for those not receiving judicious sun exposure and those with no contra-indications would likely achieve normalized levels in more than 93% of patients, without risk of toxicity. Explicit directives regarding vitamin D assessment and management are urgently required.

Vitamin D and aging

Recent studies using genetically modified mice, such as FGF23-/- and Klotho-/- mice that exhibit altered mineral homeostasis due to a high vitamin D activity showed features of premature aging that include retarded growth, osteoporosis, atherosclerosis, ectopic calcification, immunological deficiency, skin and general organ atrophy, hypogonadism and short lifespan. The phenotype reversed by normalizing vitamin D and/or mineral homeostasis. Thus, hypervitaminosis D due to an increased 1alpha-hydroxylase activity seems to be a cause of the premature aging. In several studies, we have described that a complete or partial lack of vitamin D action (VDR-/- mice and CYP27B1-/-) show almost similar phenotype as FGF23-/- or Klotho-/- mice. VDR mutant mice have growth retardation, osteoporosis, kyphosis, skin thickening and wrinkling, alopecia, ectopic calcification, progressive loss of hearing and balance as well as short lifespan. CYP27B1-/- mice do not show alopecia nor balance deficit, which might be apoVDR-dependent or calcidiol-dependent. The features are typical to premature aging. The phenotype is resistant to a normalization of the mineral homeostasis by a rescue diet containing high calcium and phosphate. Taken together, aging shows a U-shaped dependency on hormonal forms of vitamin D suggesting that there is an optimal concentration of vitamin D in delaying aging phenomena. Our recent study shows that calcidiol is an active hormone. Since serum calcidiol but not calcitriol is fluctuating in physiological situations, calcidiol might determine the biological output of vitamin D action. Due to its high serum concentration and better uptake of calcidiol-DBP by the target cells through the cubilin-megalin system, calcidiol seems to be an important circulating hormone. Therefore, serum calcidiol might be associated with an increased risk of aging-related chronic diseases more directly than calcitriol. Aging and cancer seem to be tightly associated phenomena. Accumulation of damage on DNA and telomeres cause both aging and cancer, moreover the signalling pathways seem to converge on tumour suppressor protein, p53, which seems to be regulated by vitamin D. Also, the insulin-like growth factor signalling pathway (IGF-1, IGFBPs, IGFR) and fibroblast growth factor-23 (FGF-23) regulate growth, aging and cancer. Vitamin D can regulate these signalling pathways, too. Also NF-kappaB and telomerase reverse transcriptase (TERT) might be molecular mechanisms mediating vitamin D action in aging and cancer. Calcidiol serum concentrations show a U-shaped risk of prostate cancer suggesting an optimal serum concentration of 40-60 nmol/L for the lowest cancer risk. Therefore, it is necessary to study several common aging-associated diseases such as osteoporosis, hypertension and diabetes known to be vitamin D-dependent before any recommendations of an optimal serum concentration of calcidiol are given.

Solar ultraviolet-B irradiance and vitamin D may reduce the risk of septicemia

The primary features of the epidemiology of septicemia in the United States include highest rates in winter and the Northeast, lowest in fall and in the West; higher rates among African Americans than white Americans; a rapid increase in incidence with age; comorbidity with several chronic and infectious diseases; and a rapid increase in incidence rate starting in the early 1980s. This article reviews the literature on the epidemiology of septicemia in the United States, along with the roles of solar ultraviolet-B (UVB) and vitamin D3 related to the more important features. Solar UVB doses in summer are highest in the Southwest and lowest in the Northeast. Serum 25-hydroxyvitamin D [25(OH)D] levels are highest in summer, lowest in winter. African Americans have much lower 25(OH)D levels than those of white Americans. Serum 25(OH)D levels decline rapidly with advancing age. The risk of diseases comorbid with septicemia are generally inversely correlated with serum 25(OH)D levels. Sun-avoidance messages may have led to lower population levels of 25(OH)D, although prevalence of antibiotic-resistant bacteria may have increased. Previous reports have shown that 1,25-dihydroxyvitamin D upregulates human cathelicidin, LL-37, which has antimicrobial as well as antiendotoxin activity. The general agreement between the epidemiology of septicemia in the United States and the variations of solar UVB and the effects of vitamin D supports the hypothesis that both play important roles in reducing the risk of septicemia. Further study is warranted to evaluate this hypothesis.

The paradoxical effects of vitamin D on type 1 mediated immunity

Low vitamin D status is associated with an increased risk of Th1 mediated autoimmune diseases like inflammatory bowel disease. 1,25(OH)(2)D(3) treatments have been shown to suppress Th1 mediated immunity and protect animals from experimental autoimmunity. Th1 mediated immunity is important for clearance of a number of different infectious diseases. For tuberculosis 1,25(OH)(2)D(3) treatment is associated with decreased Th1 mediated immunity but increased bactericidal activity. Systemic candidiasis is unaffected by 1,25(OH)(2)D(3) treatment. The seemingly paradoxical effects of 1,25(OH)(2)D(3) and vitamin D on Th1 mediated autoimmunity versus infectious immunity point to a broad array of vitamin D targets in the immune system. The interplay of these vitamin D targets and their impact on the host-immune response then dictate the outcome.

Active crohn disease and hypercalcemia treated with infliximab: case report and literature review

OBJECTIVE

To report a case of 1,25-dihydroxyvitamin D-mediated hypercalcemia caused by active Crohn disease that improved with infliximab therapy.

METHODS

We present the clinical and laboratory findings and describe the clinical course of a patient who had hypercalcemia during Crohn disease exacerbations. The literature is reviewed regarding 1,25-dihydroxyvitamin D production in Crohn disease, and the 3 cases of hypercalcemia in individuals with Crohn disease reported in the literature are described.

RESULTS

A 50-year-old man with long-standing Crohn disease treated with multiple bowel resections presented for take-down ileostomy. He was hypercalcemic and had suppressed parathyroid hormone and parathyroid hormone-related peptide levels. Histopathology of the resected ileostomy site and adjacent small bowel indicated active Crohn disease. Hypercalcemia promptly resolved after a few days of treatment with intravenous glucocorticoids. One month later, hypercalcemia recurred in the presence of an inappropriately high 1,25-dihydroxyvitamin D level and increased urinary calcium and serum angiotensin-converting enzyme levels. The serum and urinary calcium levels became normal with infliximab therapy. Three previous reports of hypercalcemia caused by active Crohn disease describe effective treatment with glucocorticoids. This is the first report of successful response to infliximab in this setting.

CONCLUSION

Hypercalcemia mediated by 1,25-dihydroxyvitamin D in the setting of Crohn disease may respond to glucocorticoid-sparing immunomodulators.

Juvenile sarcoidosis presenting as Crohn's disease

A 12-year-old Turkish girl suffered from abdominal pain located in the right lower abdomen for 3 weeks. Ultrasound revealed palisade-like swelling of the mucosa in the ileum. Gastrointestinal biopsy showed incipient granulomas in the stomach and moderate fibrosis of the terminal ileum. Subsequently, bilateral hilar adenopathy and an abnormal level of serum angiotensin-converting enzyme were detected. The relevance of paediatric sarcoidosis mimicking Crohn's disease is discussed.

Competing with Crohn's disease: management issues in active patients

Crohn's disease is a chronic inflammatory bowel disorder that has genetic and environmental risk factors. Although moderate physical activity seems to reduce the risk of developing Crohn's disease, some high-performance athletes live with the disease. Uncontrolled Crohn's disease predisposes patients to numerous nutrient deficiencies and associated health issues such as anemia and osteoporosis. Low-intensity exercise has been shown to decrease flare-ups in sedentary patients; however, high-intensity exercise may lead to increased symptoms. Physicians play a crucial role in coordinating a team approach among the athlete, parents, coach, and athletic trainers to provide the best possible management of diet, training schedule, and treatment.