Vitamin-D status and mineral metabolism in two ethnic populations with sarcoidosis

Corticosteroid use in chronic dermatologic disorders and osteoporosis

Glucocorticoid-induced osteoporosis (GIOP) is a frequently encountered and serious side effect of glucocorticoid use. Bone loss leading to an increased risk for fracture occurs early in the use of glucocorticoids, yet patients at risk for this complication are often undertreated. All physicians prescribing glucocorticoids should therefore be familiar with a basic approach to anticipating and preventing GIOP when starting patients on glucocorticoid therapy. This manuscript and its case vignettes are designed to help dermatologists assess and manage bone health to prevent GIOP in patients receiving glucocorticoid therapy.

Treatment of Sarcoidosis: A Multidisciplinary Approach

Sarcoidosis is a systemic disease of unknown etiology defined by the presence of noncaseating granulomatous inflammation that can cause organ damage and diminished quality of life. Treatment is indicated to protect organ function and decrease symptomatic burden. Current treatment options focus on interruption of granuloma formation and propagation. Clinical trials guiding evidence for treatment are lacking due to the rarity of disease, heterogeneous clinical course, and lack of prognostic biomarkers, all of which contribute to difficulty in clinical trial design and implementation. In this review, a multidisciplinary treatment approach is summarized, addressing immunuosuppressive drugs, managing complications of chronic granulomatous inflammation, and assessing treatment toxicity. Discovery of new therapies will depend on research into pathogenesis of antigen presentation and granulomatous inflammation. Future treatment approaches may also include personalized decisions based on pharmacogenomics and sarcoidosis phenotype, as well as patient-centered approaches to manage immunosuppression, symptom control, and treatment of comorbid conditions.

The role of vitamin D in sarcoidosis

After the initial description of extrarenal synthesis of 1,25-dihydroxyvitamin D (1,25-(OH)₂D) three decades ago, extensive progress has been made in unraveling the immunomodulatory roles of vitamin D in the pathogenesis of granulomatous disorders, including sarcoidosis. It has been shown that 1,25-(OH)₂D has dual effects on the immune system, including upregulating innate immunity as well as downregulating the autoimmune response. The latter mechanism plays an important role in the pathogenesis and treatment of sarcoidosis. Vitamin D supplementation in patients with sarcoidosis has been hampered owing to concerns about the development of hypercalcemia and hypercalciuria given that extrarenal 1-α hydroxylase is substrate dependent. Recently, a few studies have cast doubt over the mechanisms underlying the development of hypercalcemia in this population. These studies demonstrated an inverse relationship between the level of vitamin D and severity of sarcoidosis. Consequently, clinical interest has been piqued in the use of vitamin D to attenuate the autoimmune response in this disorder. However, the development of hypercalcemia and the attendant detrimental effects are real possibilities. Although the average serum calcium concentration did not change following vitamin D supplementation, in two recent studies, hypercalciuria occurred in one out of 13 and two out of 16 patients. This review is a concise summary of the literature, outlining past work and newer developments in the use of vitamin D in sarcoidosis. We feel that larger-scale placebo-controlled randomized studies are needed in this population. Since the current first-line treatment of sarcoidosis is glucocorticoids, which confer many systemic adverse effects, and steroid-sparing immunosuppressant treatment options carry additional risks of adverse effects, adjunct management with vitamin D in combination with potent anti-osteoporotic medications could minimize the risk of glucocorticoid-induced osteoporosis and modulate the immune system to attenuate disease activity in sarcoidosis.

Balancing Altered Calcium Metabolism with Bone Health in Sarcoidosis

Abnormal calcium metabolism in sarcoidosis patients can lead to hypercalcemia, hypercalciuria, and kidney stones. Hypercalcemia in sarcoidosis is usually due to increased activity of 1α-hydroxylase in macrophages of pulmonary granulomata, resulting in low levels of 25-hydroxyvitamin D and high levels of calcitriol. Vitamin D supplementation may be dangerous for some sarcoidosis patients and is recommended only for those with decreased 25-hydroxyvitamin D and reduced or normal calcitriol level. Diagnosis, treatment of osteoporosis, and maintenance of bone health are complex issues for sarcoidosis patients. An approach to diagnosis and treatment of bone fragility is presented.

Diagnosis and Detection of Sarcoidosis. An Official American Thoracic Society Clinical Practice Guideline

Background: The diagnosis of sarcoidosis is not standardized but is based on three major criteria: a compatible clinical presentation, finding nonnecrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. There are no universally accepted measures to determine if each diagnostic criterion has been satisfied; therefore, the diagnosis of sarcoidosis is never fully secure.

Methods: Systematic reviews and, when appropriate, meta-analyses were performed to summarize the best available evidence. The evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation approach and then discussed by a multidisciplinary panel. Recommendations for or against various diagnostic tests were formulated and graded after the expert panel weighed desirable and undesirable consequences, certainty of estimates, feasibility, and acceptability.

Results: The clinical presentation, histopathology, and exclusion of alternative diagnoses were summarized. On the basis of the available evidence, the expert committee made 1 strong recommendation for baseline serum calcium testing, 13 conditional recommendations, and 1 best practice statement. All evidence was very low quality.

Conclusions: The panel used systematic reviews of the evidence to inform clinical recommendations in favor of or against various diagnostic tests in patients with suspected or known sarcoidosis. The evidence and recommendations should be revisited as new evidence becomes available.

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.

ERK1,2 Signalling Pathway along the Nephron and Its Role in Acid-base and Electrolytes Balance

Mitogen-activated protein kinases (MAPKs) are intracellular molecules regulating a wide range of cellular functions, including proliferation, differentiation, apoptosis, cytoskeleton remodeling and cytokine production. MAPK activity has been shown in normal kidney, and its over-activation has been demonstrated in several renal diseases. The extracellular signal-regulated protein kinases (ERK 1,2) signalling pathway is the first described MAPK signaling. Intensive investigations have demonstrated that it participates in the regulation of ureteric bud branching, a fundamental process in establishing final nephron number; in addition, it is also involved in the differentiation of the nephrogenic mesenchyme, indicating a key role in mammalian kidney embryonic development. In the present manuscript, we show that ERK1,2 signalling mediates several cellular functions also in mature kidney, describing its role along the nephron and demonstrating whether it contributes to the regulation of ion channels and transporters implicated in acid-base and electrolytes homeostasis.

Serum and urinary calcium level in Latvian patients with sarcoidosis

Objectives

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that in 90% of cases affects the lungs. Calcium metabolism testing can be useful in diagnostics. The aim of the study was to assess the correlation between calcium metabolism and sarcoidosis form of manifestation/demographic indicators.

Material and methods

In a retrospective study medical records of all patients (n = 699) who had been hospitalized with suspected sarcoidosis in a specialized clinic of Riga Eastern Clinical University Hospital during the period from January 1^st, 2013 until December 31^st, 2014 were analyzed. Further analysis included only patients with histologically and/or clinically confirmed sarcoidosis (n = 281).

Results

Patients’ average age at the time of diagnosis was 39 ±13 years. Elevated serum calcium was observed in 9.9% of cases. A statistically significant correlation was found between serum calcium and age (p < 0.01). There was an association between serum calcium and gender (p < 0.05) – levels were higher in men (2.43 mmol/l) than in women (2.40 mmol/l). Elevated calcium in 24-hour urine was observed in 22.7% of patients. The mean value was 232.3 mg/24 h, levels were higher in men (258.7 mg/24 h) than in women (202.3 mg/24 h), and the association with gender was statistically significant (p < 0.01).

Conclusions

We can conclude that in Latvia sarcoidosis affects mostly young and middle-aged people. Both serum calcium and calcium in 24-hour urine are important parameters for sarcoidosis diagnostics. Hypercalcemia was found in 9.9% of patients, hypercalciuria in 22.7% of patients, and both were statistically significantly higher in men, regardless of age.

Vitamin D status in sarcoidosis: a cross-sectional study

Background: Hypercalcemia, a common feature in sarcoidosis, is due to the excessive production of active Vitamin D metabolite, 1,25(OH)₂D. Levels of 25(OH) Vitamin D however may not be appropriate. Objectives: To assess Vitamin D status and its clinical associations in sarcoidosis patients compared to a general respiratory diseases out-patient clinic population, serving as controls. Methods: 64 sarcoidosis cases and 53 control cases with other than sarcoidosis respiratory diseases, matched for age and sex were included in the study. Serum 25(OH)D, 1,25(OH)₂D, calcium, angiotensin converting enzyme (ACE) were measured. 25(OH) Vitamin D was described as deficient when <20 ng/ml and insufficient when <30 ng/ml. Clinical parameters were recorded for sarcoidosis cases. Results: Overall 41/64 sarcoidosis cases (64%) had low 25(OH) D, 7/64 (11%) had high 1,25(OH)₂D and 2/64 had hypercalcaemia (3%). Sarcoidosis subjects likely exhibited deficient (39%) or normal 25(OH)D levels (36%) in comparison to controls (p=0.018). 25(OH) Vitamin D deficiency in sarcoidosis was associated with race and radiological stage I disease, with regression analysis identifying African-American race as the only significant risk factor (p=0.03). An inverse correlation between ACE and 25(OH)D levels was found (p=0.052). 1,25(OH)₂D was significantly elevated in sarcoidosis compared to controls. Among sarcoidosis patients, those with insufficient 25(OH)D levels exhibited higher calcium levels in serum. Conclusions: 25(OH) Vitamin D deficiency is prevalent in sarcoidosis, particularly in African-Americans and likely those with active disease. However, concomitant 1,25(OH)₂D elevation and associated hypercalcaemia make Vitamin D supplementation dangerous in sarcoidosis. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 154-159).

Current concepts regarding calcium metabolism and bone health in sarcoidosis

PURPOSE OF REVIEW

Vitamin D supplementation is widespread used in the general population. In sarcoidosis, up to 50% of patients, especially postmenopausal women and those taking corticosteroids, show evidence of increased bone fragility. The purpose of this review is to provide an evidence-based rationale on how to treat sarcoidosis patients with bone health issues.

RECENT FINDINGS

Evidence from observational studies show that decreased 25-hydroxy vitamin D is common in sarcoidosis. However, the great majority of sarcoidosis patents have normal or often elevated levels of 1,25-dihydroxy vitamin D (calcitriol), a marker associated with disease activity. High calcitriol levels may often be associated with hypercalcemia and hypercalcuria. The few interventional randomized controlled studies in the field, suggest that vitamin D supplementation may not be well tolerated because of hypercalcemia, moreover without substantial benefit on bone health and risk for fractures in these patients.

SUMMARY

Vitamin D supplementation may be withheld in sarcoidosis patients with bone fragility, unless calcitriol levels are below normal limits. A treating scheme is proposed.