Dissociation between the Effects of Endogenous Parathyroid Hormone on Adenosine 3″5″Monophosphate Generation and Phosphate Reabsorption in Hypocalcemia due to Vitamin D Depletion: An Acquired Disorder Resembling Pseudohypoparathyroidism Type II

Introduction: This study aims to assess the status of serum vitamin D, parathyroid hormone, type II collagen, calcium, phosphate,albumin, and alkaline phosphatase in osteoarthritis and rheumatoidarthritis patients and to study their association with rheumatoid arthritis disease activity. Materials and Methods: This prospectivecross-sectional study was conducted at the clinical analysis department, College of Pharmacy, Hawler Medical University in 2017.They study samples were collected at Rizgary Teaching Hospitalduring the period September 2015 to January 2016. A total of(N=156) participants were included: (N=53) patients with rheumatoid arthritis (RA), (N=53) with osteoarthritis (OA), and (N=50)healthy controls. Enzyme Linked Immuno Sorbent Assay kits determined serum vitamin D, parathyroid hormone, and type II collagen; and serum albumin, calcium, phosphate and alkaline phosphatase, were determined by standard colorimetric methods. Resultsand Discussion: Statistically significant higher levels of parathyroid hormone and type II collagen, with lower levels of Vitamin D,were found in the osteoarthritis group than the rheumatoid arthritisgroup and the healthy controls (P=0.007, P<0.001, P= 0.005) respectively. Multiple linear regression showed a statistically significant difference in serum type II collagen as a dependent variable, inpatients suffering from RA or OA compared to the healthy controlgroup; after adjusting for the effect of other independent studyvariables, there was a mean increase of (45.90 nmol/L, P<0.001)in RA patients, and OA patients showed greater levels of type IIcollagen (73.950 nmol/L) than the health control group (P<0.001).Conclusions: Elevated type II collagen levels, in conjunction witha low vitamin D status, may be strong discriminator between osteoarthritis and rheumatoid arthritis patients.

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Stage I Vitamin D-Deficiency Rickets Mimicking Pseudohypoparathyroidism Type II

Clinical Pediatrics ◽

10.1177/000992280204100411 ◽

2002 ◽

Vol 41 (4) ◽

pp. 263-268 ◽

Cited By ~ 17

Author(s):

Tarak Srivastava ◽

Uri S. Alon

Keyword(s):

Vitamin D ◽

Vitamin D Deficiency ◽

Stage I ◽

Type Ii ◽

Deficiency Rickets ◽

Pseudohypoparathyroidism Type Ii

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Calcium and Vitamin D Depletion and Elevated Parathyroid Hormone following Biliopancreatic Diversion

Obesity Surgery ◽

10.1381/096089203322618722 ◽

2003 ◽

Vol 13 (6) ◽

pp. 893-895 ◽

Cited By ~ 107

Author(s):

Leyanne Newbury ◽

Kevin Dolan ◽

Michael Hatzifotis ◽

Nadeen Low ◽

George Fielding

Keyword(s):

Vitamin D ◽

Parathyroid Hormone ◽

Biliopancreatic Diversion ◽

Vitamin D Depletion

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Pseudohypoparathyroidism Type II: Restoration of Normal Renal Responsiveness to Parathyroid Hormone by Calcium Administration

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem-39-4-693 ◽

1974 ◽

Vol 39 (4) ◽

pp. 693-701 ◽

Cited By ~ 66

Author(s):

HECTOR J. RODRIGUEZ ◽

HERMAN VILLARREAL ◽

SAULO KLAHR ◽

EDUARDO SLATOPOLSKY

Keyword(s):

Parathyroid Hormone ◽

Type Ii ◽

Pseudohypoparathyroidism Type Ii

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Control of Renal Tubular Phosphate Reabsorption by Parathyroid Hormone in Man

Clinical Science ◽

10.1042/cs0530431 ◽

1977 ◽

Vol 53 (5) ◽

pp. 431-438

Author(s):

D. A. Walker ◽

S. Joyce Davies ◽

K. Siddle ◽

J. S. Woodhead

Keyword(s):

Vitamin D ◽

Parathyroid Hormone ◽

Cyclic Amp ◽

Primary Hyperparathyroidism ◽

Normal Subjects ◽

Vitamin D Metabolism ◽

Phosphate Reabsorption ◽

Important Regulator ◽

Urinary Cyclic Amp ◽

Renal Tubular

1. The maximum tubular reabsorption capacity for phosphate relative to glomerular filtration rate (Tm,P/GFR) was found to range from 0·8 to 1·5 mmol/l in 32 normal fasting subjects. In 14 patients with primary hyperparathyroidism and five patients with hyperparathyroidism secondary to vitamin D deficiency or malabsorption values ranged from 0·2 to 0·8 mmol/l. 2. Plasma parathyroid hormone concentrations measured by an immunoradiometric technique ranged from <0·15 to 0·9 ng/ml in the normal subjects and from 0·5 to 10 ng/ml in the patients with hyperparathyroidism. There was no correlation, however, between plasma parathyroid hormone and Tm,P/GFR in either normal or abnormal groups. 3. Plasma parathyroid hormone was lower in 11 out of 13 patients with primary hyperparathyroidism 3 or 4 weeks after tumour removal than immediately before the operation. In all cases there was a rise in Tm,P/GFR, though not all values were normalized. 4. Changes in plasma parathyroid hormone, Tm,P/GFR and plasma and urinary cyclic AMP concentrations were measured during infusion of bovine parathyroid hormone into normal fasting subjects. Phosphate reabsorption fell markedly in response to low doses of parathyroid hormone (0·5 i.u. h−1 kg−1), higher doses (4 i.u. h−1 kg−1) producing little additional change in Tm,P/GFR despite large changes in cyclic AMP excretion. At the highest doses used (8 i.u. h−1 kg−1) apparent saturation of the renal adenylate cyclase occurred. During an infusion of hormone, 0·25 i.u. h−1 kg−1 over 3 h, a fall in Tm,P/GFR was recorded at concentrations of immunoreactive parathyroid hormone within the normal range for endogeneous hormone. At such concentrations it was not possible to detect significant changes in either plasma or urine cyclic AMP. 5. It is concluded that parathyroid hormone is an important regulator of renal phosphate handling under normal physiological conditions. Such a regulatory process has been implicated in the control of vitamin D metabolism.

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Hereditary Vitamin-D Dependent Rickets Type II: A Case Report

Journal of Nepal Medical Association ◽

10.31729/jnma.6411 ◽

2021 ◽

Vol 59 (238) ◽

Author(s):

Neela Sunuwar ◽

Swotantra Gautam ◽

Anuradha Twayana ◽

Saroj Adhikari Yadav ◽

Firoz Anjum ◽

...

Keyword(s):

Vitamin D ◽

Case Report ◽

Parathyroid Hormone ◽

Biochemical Parameters ◽

Genetic Disorder ◽

High Dose ◽

Type Ii ◽

Radiological Findings ◽

Oral Calcium ◽

Subsequent Improvement

Hereditary vitamin D dependent rickets type II is a rare genetic disorder in children characterized by early onset of rickets and deranged biochemical parameters. Low serum calcium level, high alkaline phosphatase, high parathyroid hormone, and high values of 1,25-dihydroxy vitamin D are characteristic biochemical findings. We are reporting a rare case of Vitamin D Dependent Rickets and subsequent improvement after addition of cinacalcet. This is a case report of a 2.5-year-child with Hereditary Vitamin D Dependent Rickets type II receiving cinacalcet as adjunct to oral calcium and calcitriol. Oral cinacalcet (0.25mg/kg/day) was added to the regimen as an adjunct after treatment failure with high dose of oral calcium and calcitriol. A significant improvement in radiological findings and normal homeostasis of calcium, phosphate and parathyroid hormone was achieved after initiation of cinacalcet.

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