Nephron 17: 144-154(1976)
Parathyroid Hormone Plasma Level in Untreated Chronic Renal Failure and in Hemodialyzed Patients M. Fuss, M. D e Backer, J. B rauman, N. N iis-D ewolf, T. M anderlier, H. Brauman and J. C orvilain Hôpital Brugmann, Service de Médecine interne et de Biologie clinique, Université Libre de Bruxelles, et Fondation Reine Elisabeth, Brussels
Key Words. Parathyroid hormone • Chronic renal failure • Hemodialysis • Ionized calcium Abstract. In 42 untreated patients at various stages of chronic renal failure, plasma level of parathyroid hormone was directly proportional to the degree of renal failure and inversely proportional to the serum calcium level. Plasma parathyroid hormone levels were frequently elevated in 21 patients undergoing regular dialysis treatment, in spite of normal levels of serum total calcium and magnesium. Serum-ionized calcium levels measured in dialyzed patients were usually reduced and inversely correlated with the creatinine levels. Parathyroid hormone levels were correlated with the creatinine levels, but the inverse relationship with ionized calcium was not significant.
Introduction Hypersecretion of parathyroid hormone (PTH) in chronic renal failure (CRF) was clearly demonstrated when Berson and Y alow [1] measured
Received: April 28, 1975; accepted: August 27,1975.
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PTH plasma level by radioimmunoassay. However, the pathogenesis of this secondary hyperparathyroidism is still a matter of discussion. The two causes generally advocated are the lack of active form of vitamin D [2] and phosphate retention [3,4], Since both etiological factors would stimulate PTH secretion through a reduction of calcium blood level, one might expect to find relation ships between calcium, phosphate and PTH in CRF. In order to verify if such relationships exist in CRF, we measured serum phosphate (P) and total calcium (CaT), and PTH plasma levels in patients at
Fuss et al.
145
various stages of CRF (group 1). None of them had been treated by hemo dialysis and most of them were hypocalcémie. In other patients submitted to regular dialysis treatment (group 2), in whom calcemia was usually normal, we also measured other parameters such as serum-ionized calcium (Ca++) and magnesium (Mg).
Group 1 consisted of 42 patients (23 men and 19 women with an age range of 23-80 years) with CRF of different origins (glomerulonephritis, pyelonephritis, polycystic kidneys, phenacetin nephropathy...). None of this patients was bedridden at the time of the study. Their serum creatinine levels ranged from 1.1 to 18.0 mg/100 ml. Two patients were found with upper normal creatinine levels (1.1 mg/100 ml), and a creatinine clearance rate less than 65 ml/min. None of the 42 patients had been treated by hemodialysis, calcium supple ments, vitamin D or phosphate-binding agents. Group 2 comprised 21 outpatients with end-stage CRF treated by biweekly 8-hour hemodialysis, using a dialysate calcium concentration of 8 mg/100 ml and an Mg concentra tion of 1.3 mg/100 ml. Seven patients had been submitted to bilateral nephrectomy. Clinical data concerning these 21 patients are reported in table I. The control group consisted of 16 patients hospitalized for functional disorders with normal renal function and no disturbance of the calcium metabolism. All the biological measurements were made on arterial blood except in the group 1 patients in whom venous blood was used. Samples were collected immediately prior to dialysis in patients of group 2. Plasma immunoreactive PTH (iPTH) was determined by radioimmunoassay [5], using the CH 12 antiserum from Arnaud’s Laboratory. An extract of parathyroid adenoma of unknown concentration was used as a standard. Our results were expressed as microliter equivalents of the diluted standard per milliliter (p.1 Eq/ml). Technical laboratory condi tions for this research determined a normal upper limit of 25 ¡xl Eq/ml. Our assay was not sensitive enough to distinguish absolute values between 0 and 5 p.1 Eq/ml so that values inferior to 5 p.1 Eq/ml were assigned the value of 5 ¡xl Eq/ml for com putational purposes. We think that the CH 12 antiserum recognizes the active 9,500 molec ular weight (mol.wt.) form of circulating PTIT better than the 7,000 mol.wt. inactive frag ment. Our opinion is based on studies made in patients with primary hyperparathyroidism. (1) The half-life of plasma PTH measured with CH 12 antiserum after removal of parathy roid adenoma was about 20 min [6], This value agrees with other results found for the 9,500 mol.wt. form [7], The same authors also found that the half-life of the 7,000 mol.wt. frag ment was longer than 30 min [7], (2) The renal extraction ratio of PTH measured with CH 12 and CH 14 antiserum are very similar (0.36 and 0.43, respectively), whereas it is negligible (0.08) with GP 1 antiserum [8], It was demonstrated that CH 14 antiserum identifies the 9.500 but not the 7,000 mol.wt. form of PTH, whereas GP 1 antiserum recognizes also the 7,000 mol.wt. fragment of the molecule [9], Serum creatinine, P and CaT in patients of group 1 were measured by using a Technicon Autoanalyzer. In patients of group 2 and in control subjects, serum CaT was determined
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Material and Methods
Fuss el al.
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Table I. Clinical data and blood values of 21 patients on regular dialysis treatment Patient
Blood values
case sex age, diag- Durayears nosis tion of treatment, months
Creati- CaT, Ca++ Ca.++/ P Mg, nine, CaT, mg/ mg/ % mg/ mg/ mg/ 100 ml 100 ml 100 ml 100 ml 100 ml
N .E.1 M M.E-iF E.C. M P.A.1 M P.O.1 M W. A. F S.P. F S.C. F B.I. M V.B. F H.A. M D .H . M M.A. F D.U. M G.H.»F S.E. M J.U . M W.O. M B.O.1 F V.S. F S. M.1 M Mean ±SEM
50 32 26 32 18 40 26 42 47 42 37 26 23 49 36 51 43 49 37 31 42
CPN CGN CPN CPN PCK CGN CPN CPN CPN CGN CGN CGN CGN CPN CPN CPN CGN CGN CPN CPN CPN
2 19 34 44 32 4 3 2 32 12 15 5 1 6 30 12 41 21 2 33 9 17 3
10.8 10.8 16.3 18.6 21.0 15.0 10.0 13.0 13.2 13.5 15.9 10.8 14.1 12.0 21.0 17.4 16.8 9.9 12.5 13.5 16.5 14.4 0.7
9.6 11.1 9.9 9.4 8.5 9.7 9.4 9.7 8.6 11.2 10.1 9.4 9.2 9.7 9.4 10.0 8.1 8.8 9.4 9.4 9.4 9.5 0.2
3.97 4.08 3.90 3.56 2.87 3.61 3.88 3.75 3.80 4.67 3.75 4.30 3.38 3.77 3.08 3.64 2.84 3.42 3.57 3.38 4.16 3.68 0.1
41.4 36.8 39.4 37.9 33.8 37.2 41.3 38.6 44.2 41.7 37.1 45.7 36.7 38.9 32.8 36.4 35.1 38.9 38.0 36.0 44.3 38.7 0.7
6.7 7.0 9.6 8.1 12.5 8.3 3.8 5.9 7.8 9.2 10.8 5.6 7.0 3.2 9.2 7.2 7.7 9.5 7.3 6.9 6.5 7.6 0.5
— 2.30 2.54 2.61 2.44 2.09 2.51 2.57 2.45 4.12 2.36 2.97 2.42 2.97 3.44 2.19 2.51 2.73 2.57 2.88 2.67 0.11
Protein, g/ 100 ml
Albu- pH min, g/ 100 ml
6.3 5.7 6.3 7.0 6.7 6.4 6.5 6.7 6.4 7.5 7.2 5.6 6.5 6.9 6.5 6.9 6.6 7.4 6.2 6.1 6.3 6.6 0.1
3.4 3.6 3.5 4.1 3.7 4.0 4.0 4.8 4.2 3.7 4.0 3.0 4.1 4.2 3.6 3.9 3.6 2.9 3.4 3.5 3.9 3.8 0.1
7.41 7.40 7.30 7.35 7.38 7.39 7.38 7.36 7.21 7.32 7.17 7.39 7.38 7.36 7.33 7.21 7.39 7.22 7.39 7.38 7.33 7.34 0.02
PTH, Pi Eq/ml
5 14 240 60 200 16 57 26 50 34 19 7 35 98 78 125 60 120 20 29 21 63 14
by the method of C lark and C ollip [10] and serum magnesium by the technique of O range and R hein [11], Serum total protein was determined by the technique of M oore and Sax [12] and albumin by electrophoresis on cellulose acetate membrane [13]. Arterial pH was routinely measured. Serum-ionized calcium was measured by using a model 92-20 serum calcium flow-thru electrode (instruction manual, calcium activity electrode, model 92-20, Orion Research Inc., 1966). The electrode was calibrated with calcium standards, containing 0.5, 1.0 and 2.0 mM of calcium chloride and 150 mM of sodium chloride per liter. The standard solutions
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 9/19/2018 12:52:29 PM
1 Patients with bilateral nephrectomy. CPN = Chronic pyelonephritis; CGN ==chronic glomerulonephritis; PCK = polycystic kidneys.
Parathyroid Hormone in Chronic Renal Failure and Hemodialysis
147
Fig.l. Relationship between plasma parathyroid hormone and serum creatinine in un treated renal failure; r=0.73, p < 0.001.
were prepared without trypsin and triethanolamine. The determinations of ionized calcium were carried out at room temperature from arterial blood drawn anaerobically in plastic disposable syringes. The results were not corrected for temperature.
Group 2 and Control Subjects Table I shows the blood values as well as some clinical data concerning all patients on regular dialysis treatment. The prominent data for these patients
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 9/19/2018 12:52:29 PM
Results Group 1 Prominent data concerning the 42 untreated patients are shown in figures 1-4. The calculation of the linear relationship between the different para meters measured revealed positive correlations between iPTH and creatinine (p
Parathyroid Hormone Plasma Level in Untreated Chronic Renal Failure and in Hemodialyzed Patients M. Fuss, M. D e Backer, J. B rauman, N. N iis-D ewolf, T. M anderlier, H. Brauman and J. C orvilain Hôpital Brugmann, Service de Médecine interne et de Biologie clinique, Université Libre de Bruxelles, et Fondation Reine Elisabeth, Brussels
Key Words. Parathyroid hormone • Chronic renal failure • Hemodialysis • Ionized calcium Abstract. In 42 untreated patients at various stages of chronic renal failure, plasma level of parathyroid hormone was directly proportional to the degree of renal failure and inversely proportional to the serum calcium level. Plasma parathyroid hormone levels were frequently elevated in 21 patients undergoing regular dialysis treatment, in spite of normal levels of serum total calcium and magnesium. Serum-ionized calcium levels measured in dialyzed patients were usually reduced and inversely correlated with the creatinine levels. Parathyroid hormone levels were correlated with the creatinine levels, but the inverse relationship with ionized calcium was not significant.
Introduction Hypersecretion of parathyroid hormone (PTH) in chronic renal failure (CRF) was clearly demonstrated when Berson and Y alow [1] measured
Received: April 28, 1975; accepted: August 27,1975.
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 9/19/2018 12:52:29 PM
PTH plasma level by radioimmunoassay. However, the pathogenesis of this secondary hyperparathyroidism is still a matter of discussion. The two causes generally advocated are the lack of active form of vitamin D [2] and phosphate retention [3,4], Since both etiological factors would stimulate PTH secretion through a reduction of calcium blood level, one might expect to find relation ships between calcium, phosphate and PTH in CRF. In order to verify if such relationships exist in CRF, we measured serum phosphate (P) and total calcium (CaT), and PTH plasma levels in patients at
Fuss et al.
145
various stages of CRF (group 1). None of them had been treated by hemo dialysis and most of them were hypocalcémie. In other patients submitted to regular dialysis treatment (group 2), in whom calcemia was usually normal, we also measured other parameters such as serum-ionized calcium (Ca++) and magnesium (Mg).
Group 1 consisted of 42 patients (23 men and 19 women with an age range of 23-80 years) with CRF of different origins (glomerulonephritis, pyelonephritis, polycystic kidneys, phenacetin nephropathy...). None of this patients was bedridden at the time of the study. Their serum creatinine levels ranged from 1.1 to 18.0 mg/100 ml. Two patients were found with upper normal creatinine levels (1.1 mg/100 ml), and a creatinine clearance rate less than 65 ml/min. None of the 42 patients had been treated by hemodialysis, calcium supple ments, vitamin D or phosphate-binding agents. Group 2 comprised 21 outpatients with end-stage CRF treated by biweekly 8-hour hemodialysis, using a dialysate calcium concentration of 8 mg/100 ml and an Mg concentra tion of 1.3 mg/100 ml. Seven patients had been submitted to bilateral nephrectomy. Clinical data concerning these 21 patients are reported in table I. The control group consisted of 16 patients hospitalized for functional disorders with normal renal function and no disturbance of the calcium metabolism. All the biological measurements were made on arterial blood except in the group 1 patients in whom venous blood was used. Samples were collected immediately prior to dialysis in patients of group 2. Plasma immunoreactive PTH (iPTH) was determined by radioimmunoassay [5], using the CH 12 antiserum from Arnaud’s Laboratory. An extract of parathyroid adenoma of unknown concentration was used as a standard. Our results were expressed as microliter equivalents of the diluted standard per milliliter (p.1 Eq/ml). Technical laboratory condi tions for this research determined a normal upper limit of 25 ¡xl Eq/ml. Our assay was not sensitive enough to distinguish absolute values between 0 and 5 p.1 Eq/ml so that values inferior to 5 p.1 Eq/ml were assigned the value of 5 ¡xl Eq/ml for com putational purposes. We think that the CH 12 antiserum recognizes the active 9,500 molec ular weight (mol.wt.) form of circulating PTIT better than the 7,000 mol.wt. inactive frag ment. Our opinion is based on studies made in patients with primary hyperparathyroidism. (1) The half-life of plasma PTH measured with CH 12 antiserum after removal of parathy roid adenoma was about 20 min [6], This value agrees with other results found for the 9,500 mol.wt. form [7], The same authors also found that the half-life of the 7,000 mol.wt. frag ment was longer than 30 min [7], (2) The renal extraction ratio of PTH measured with CH 12 and CH 14 antiserum are very similar (0.36 and 0.43, respectively), whereas it is negligible (0.08) with GP 1 antiserum [8], It was demonstrated that CH 14 antiserum identifies the 9.500 but not the 7,000 mol.wt. form of PTH, whereas GP 1 antiserum recognizes also the 7,000 mol.wt. fragment of the molecule [9], Serum creatinine, P and CaT in patients of group 1 were measured by using a Technicon Autoanalyzer. In patients of group 2 and in control subjects, serum CaT was determined
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 9/19/2018 12:52:29 PM
Material and Methods
Fuss el al.
146
Table I. Clinical data and blood values of 21 patients on regular dialysis treatment Patient
Blood values
case sex age, diag- Durayears nosis tion of treatment, months
Creati- CaT, Ca++ Ca.++/ P Mg, nine, CaT, mg/ mg/ % mg/ mg/ mg/ 100 ml 100 ml 100 ml 100 ml 100 ml
N .E.1 M M.E-iF E.C. M P.A.1 M P.O.1 M W. A. F S.P. F S.C. F B.I. M V.B. F H.A. M D .H . M M.A. F D.U. M G.H.»F S.E. M J.U . M W.O. M B.O.1 F V.S. F S. M.1 M Mean ±SEM
50 32 26 32 18 40 26 42 47 42 37 26 23 49 36 51 43 49 37 31 42
CPN CGN CPN CPN PCK CGN CPN CPN CPN CGN CGN CGN CGN CPN CPN CPN CGN CGN CPN CPN CPN
2 19 34 44 32 4 3 2 32 12 15 5 1 6 30 12 41 21 2 33 9 17 3
10.8 10.8 16.3 18.6 21.0 15.0 10.0 13.0 13.2 13.5 15.9 10.8 14.1 12.0 21.0 17.4 16.8 9.9 12.5 13.5 16.5 14.4 0.7
9.6 11.1 9.9 9.4 8.5 9.7 9.4 9.7 8.6 11.2 10.1 9.4 9.2 9.7 9.4 10.0 8.1 8.8 9.4 9.4 9.4 9.5 0.2
3.97 4.08 3.90 3.56 2.87 3.61 3.88 3.75 3.80 4.67 3.75 4.30 3.38 3.77 3.08 3.64 2.84 3.42 3.57 3.38 4.16 3.68 0.1
41.4 36.8 39.4 37.9 33.8 37.2 41.3 38.6 44.2 41.7 37.1 45.7 36.7 38.9 32.8 36.4 35.1 38.9 38.0 36.0 44.3 38.7 0.7
6.7 7.0 9.6 8.1 12.5 8.3 3.8 5.9 7.8 9.2 10.8 5.6 7.0 3.2 9.2 7.2 7.7 9.5 7.3 6.9 6.5 7.6 0.5
— 2.30 2.54 2.61 2.44 2.09 2.51 2.57 2.45 4.12 2.36 2.97 2.42 2.97 3.44 2.19 2.51 2.73 2.57 2.88 2.67 0.11
Protein, g/ 100 ml
Albu- pH min, g/ 100 ml
6.3 5.7 6.3 7.0 6.7 6.4 6.5 6.7 6.4 7.5 7.2 5.6 6.5 6.9 6.5 6.9 6.6 7.4 6.2 6.1 6.3 6.6 0.1
3.4 3.6 3.5 4.1 3.7 4.0 4.0 4.8 4.2 3.7 4.0 3.0 4.1 4.2 3.6 3.9 3.6 2.9 3.4 3.5 3.9 3.8 0.1
7.41 7.40 7.30 7.35 7.38 7.39 7.38 7.36 7.21 7.32 7.17 7.39 7.38 7.36 7.33 7.21 7.39 7.22 7.39 7.38 7.33 7.34 0.02
PTH, Pi Eq/ml
5 14 240 60 200 16 57 26 50 34 19 7 35 98 78 125 60 120 20 29 21 63 14
by the method of C lark and C ollip [10] and serum magnesium by the technique of O range and R hein [11], Serum total protein was determined by the technique of M oore and Sax [12] and albumin by electrophoresis on cellulose acetate membrane [13]. Arterial pH was routinely measured. Serum-ionized calcium was measured by using a model 92-20 serum calcium flow-thru electrode (instruction manual, calcium activity electrode, model 92-20, Orion Research Inc., 1966). The electrode was calibrated with calcium standards, containing 0.5, 1.0 and 2.0 mM of calcium chloride and 150 mM of sodium chloride per liter. The standard solutions
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 9/19/2018 12:52:29 PM
1 Patients with bilateral nephrectomy. CPN = Chronic pyelonephritis; CGN ==chronic glomerulonephritis; PCK = polycystic kidneys.
Parathyroid Hormone in Chronic Renal Failure and Hemodialysis
147
Fig.l. Relationship between plasma parathyroid hormone and serum creatinine in un treated renal failure; r=0.73, p < 0.001.
were prepared without trypsin and triethanolamine. The determinations of ionized calcium were carried out at room temperature from arterial blood drawn anaerobically in plastic disposable syringes. The results were not corrected for temperature.
Group 2 and Control Subjects Table I shows the blood values as well as some clinical data concerning all patients on regular dialysis treatment. The prominent data for these patients
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 9/19/2018 12:52:29 PM
Results Group 1 Prominent data concerning the 42 untreated patients are shown in figures 1-4. The calculation of the linear relationship between the different para meters measured revealed positive correlations between iPTH and creatinine (p
