Aust. N.Z. 3. Med. (1975). 5, DD. 540-543
Plasma Lipids in Extra Hepatic Biliary Obstruction S. P. Mistilis',
R. Gorent, A. R. Tall$ and J. R.
Hickie"
From the Alan McGuiness Department of Gastroenterology and Lipid Clinic, Sydney Hospital and Department of Medicine, St. Vincent's Hospital, Sydney
Summary: Plasma lipids in extra hepatic biliary obstruction. S. P. Mistilis. R . Goren. A. R . Tall and J. I?.Hickie, Aust. N.Z. J. Med., 1975,5, pp. 540-543.
Detailed studies of plasma lipids and lipoproteins were carried out on a large number of patients with proven extra hepatic biliary obstruction (EHO) to determine if changes are confined to the phospholipids and cholesterol fractions or whether the hypertriglyceridaemia, found previously in isolated studies, is present consistently and to a significant degree. Plasma lipids were also compared before and after surgical relief of the obstruction. In 15 patients with EHO (aged 16 to 78 years), compared to 2 3 controls (aged 18 to 63 years), there was an increase in total cholesterol due to an increase in the unesterified fraction, increase in unesterified to esterified cholesterol ratio, increase in phospholipids and increase in phospholipid to cholesterol ratio. The most striking finding was a marked and persistent elevation of triglyceride. Furthermore the increase in triglyceride was of a similar magnitude to cholesterol and phospholipid. Following relief of obstruction the triglyceride returned to normal. The hypertriglyceridaemia in cases of EHO was associated with a clear serum and negative cold aggregation test in contrast to the changes in cases of endogenous (Type IV) hypertriglyceridaemia. Hypertriglyceridaemia in EHO was associated with a broad beta fraction on the electrophoretogram. Lipoprotein-X was also detected and persisted after the relief of the obstruction despite the return of other lipid changes to normal. This work was supported by a grant from the Raymond E. Purves Foundation. *Consultant Physicianand Gastroenterologist,Sydney Hospital. tResearch Assistant. $Raymond E. Purves Research Fellow in Liver Disease. "Professor of Medicine, Universiry of New South Wales. Correspondence; Dr. S. P. Mistilis. Alan McGuiness Department of Gastroenterology, Sydney Hospital, Sydney, N.S.W. 2000 Accepted for publication: 12 August, 1975
Many studies have described the lipid changes in liver disease and c h o l e ~ t a s i s ' ~but few have dealt specifically with extra-hepatic biliary obstruction (EHO).5-8 In the studies that have been done, patients with EHO have been shown to have elevated plasma phospholipid and cholesterol, the latter being due to an increase in the unesterified fraction. These changes have been related to the finding in the low-density lipoprotein (LDL) fraction of an abnormal lipoprotein, rich in phospholipid and unesterified cholesterol. In studies where plasma triglycerides have been measured in EHO they were shown to be normal or slightly and only a few cases have been reported with significant elevations?' Furthermore the triglyceride content of the abnormal lipoprotein in EHO has been found to be extremely In the present study we have performed detailed lipid and lipoprotein analysis on a large number of patients with proven EHO to determine if the lipid disturbance is confined to changes in phospholipid and cholesterol or whether the elevated triglyceride found previously in isolated cases is present consistently and whether the magnitude of the change is comparable to that of phospholipid and cholesterol. Lipid changes were compared before and after surgical relief of the biliary obstruction. Materials and Methods
Three groups of patients were studied: (i) 15 patients (11 males and 4 females), aged 16-78 years with proven EHO; (ii) eight patients with Fredrickson Type IV hypertriglyceridemia ;(iii) 23 controls : 14 healthy adult volunteers aged 18-32 years and nine "patient controls" aged 4763 years. Liver function tests including total alkaline phosphatase, bilirubin and serum glutamic oxaloacetic transaminase were determined with an autoanalyzer. Plasma bile salts were estimated by the steroid dehydrogenase method." For lipid analysis blood was collected in EDTA without anticoagulants and lipids were extracted from the serum by the method of Folch." Unesterified and esterified cholesterol were isolated by thin layer chromatography
DECEMBER
1975
541
LIPIDS IN EXTRA HEPATIC BILIARY OBSTRUCTION
on silica gel, using a solvent system of petroleum ether, ethyl ether and glacial acetic acid, 90 : 15 : 1.5. Triglycerides were measured by the enzymatic method of Eggstein and Kreutz” which determines the glyceride glycerol fraction in serum. Plasma from nine patients was allowed to stand overnight at 4°C and any turbidity was noted. Phospholipids were determined by the method of Bartlett13 as modified by Marinetti.14 Unesterified, esterified and total cholesterol were assayed by the method of Zlatkis, Zak and Boyle.” Electrophoresis was performed with cellulose-acetate and polyacrylamide ge1.I6 Samples of whole plasma were studied for lipoprotein-X* by imrnunodiffusion” and immunoelectrophoresis’’ using 1 % agar in barbital buffer at pH 8 . 7 .
-
Normal Controls In 151 Extra Hepatic Biliary Obstruction In = 141 lype I V Hypertriqlycerideamia In 81
.
1 4w Pldsrna Lipid levels rnq per
lMml ( m a n i SEI
3w 2w
1W
Results
Diagnosis of Extra Hepatic Biliary Obstruction All patients studied had unequivocal EHO as documented clinically and biochemically and the diagnosis was confirmed in 13 out of 15 at laparotomy. Of the patients studied seven had carcinoma of the pancreas, six had cholelithiasis and two had strictures of the common bile duct. The duration of obstruction ranged from five days to 68 weeks. Liver function tests (mean SEM) were bilirubin 12.8rfr 1.98 mg/dl (normal 1 . 2 mg/dl), serum alkaline phosphatase 492k98.4 I U (normal 140 IU) and plasma total bile salts in eight of the 14 patients was 47.1 rfr 13.7 pg/ml (normal 1 pg/ml). Plasma Lipid Changes (Figure 1 and Table 1) Individual values for various lipid classes in each patient are shown in Table 1 and the mean values (rfrSEM) are shown in Figure 1. Compared to age-matched controls and patients with type IV hyperlipidaemia, plasma total and free cholesterol, phospholipid and triglyceride concentrations were elevated in most individuals. All patients except one had at least one of these parameters above normal and the mean levels were significantly elevated compared to controls ( P < 0 . OOOS), except for the unesterified cholesterol. The most striking elevation was found in the plasma triglyceride which was 280 % of control levels, compared to phospholipid and total cholesterol which were respectively 250 % and 210% of control values. The rise in plasma triglyceride was sig*Antiserum for lipoprotein-X was kindly prepared for us by Dr. D. Seidel of Medizinische Universitatsklinik, Heidelberg Germany, by a previously described method.’
Total Cholesterol
Erterified Cholesterol
Phospholipid
lriqlyceride
FIGURE 1. Plasma lipids in controls, patients with extra hepatic biliary obstruction and endogenous (Type IV) hypertriglyceridaernia.
nificantly less ( P < O.OOO5) than levels in patients with endogenous hypertrigl yceridaemia (Type IV) and total cholesterol and phospholipid concentrations were significantly greater ( P < 0.005). A marked rise in the plasma unesterified cholesterol was seen in patients with EHO. The mean ratio of free to-esterified cholesterol was 2.32 & 0.5, which was significantly higher ( P < 0.0005) than in controls (0.38 kO.01) or patients with type IV hyperlipidaemia (0.52 & 0.05)( P < 0.005).However there was no significant difference in the absolute levels of esterified cholesterol between the three groups. The mean levels of esterified cholesterol
Plasma Lipids in Extra Hepatic Biliary Obstruction S. P. Mistilis',
R. Gorent, A. R. Tall$ and J. R.
Hickie"
From the Alan McGuiness Department of Gastroenterology and Lipid Clinic, Sydney Hospital and Department of Medicine, St. Vincent's Hospital, Sydney
Summary: Plasma lipids in extra hepatic biliary obstruction. S. P. Mistilis. R . Goren. A. R . Tall and J. I?.Hickie, Aust. N.Z. J. Med., 1975,5, pp. 540-543.
Detailed studies of plasma lipids and lipoproteins were carried out on a large number of patients with proven extra hepatic biliary obstruction (EHO) to determine if changes are confined to the phospholipids and cholesterol fractions or whether the hypertriglyceridaemia, found previously in isolated studies, is present consistently and to a significant degree. Plasma lipids were also compared before and after surgical relief of the obstruction. In 15 patients with EHO (aged 16 to 78 years), compared to 2 3 controls (aged 18 to 63 years), there was an increase in total cholesterol due to an increase in the unesterified fraction, increase in unesterified to esterified cholesterol ratio, increase in phospholipids and increase in phospholipid to cholesterol ratio. The most striking finding was a marked and persistent elevation of triglyceride. Furthermore the increase in triglyceride was of a similar magnitude to cholesterol and phospholipid. Following relief of obstruction the triglyceride returned to normal. The hypertriglyceridaemia in cases of EHO was associated with a clear serum and negative cold aggregation test in contrast to the changes in cases of endogenous (Type IV) hypertriglyceridaemia. Hypertriglyceridaemia in EHO was associated with a broad beta fraction on the electrophoretogram. Lipoprotein-X was also detected and persisted after the relief of the obstruction despite the return of other lipid changes to normal. This work was supported by a grant from the Raymond E. Purves Foundation. *Consultant Physicianand Gastroenterologist,Sydney Hospital. tResearch Assistant. $Raymond E. Purves Research Fellow in Liver Disease. "Professor of Medicine, Universiry of New South Wales. Correspondence; Dr. S. P. Mistilis. Alan McGuiness Department of Gastroenterology, Sydney Hospital, Sydney, N.S.W. 2000 Accepted for publication: 12 August, 1975
Many studies have described the lipid changes in liver disease and c h o l e ~ t a s i s ' ~but few have dealt specifically with extra-hepatic biliary obstruction (EHO).5-8 In the studies that have been done, patients with EHO have been shown to have elevated plasma phospholipid and cholesterol, the latter being due to an increase in the unesterified fraction. These changes have been related to the finding in the low-density lipoprotein (LDL) fraction of an abnormal lipoprotein, rich in phospholipid and unesterified cholesterol. In studies where plasma triglycerides have been measured in EHO they were shown to be normal or slightly and only a few cases have been reported with significant elevations?' Furthermore the triglyceride content of the abnormal lipoprotein in EHO has been found to be extremely In the present study we have performed detailed lipid and lipoprotein analysis on a large number of patients with proven EHO to determine if the lipid disturbance is confined to changes in phospholipid and cholesterol or whether the elevated triglyceride found previously in isolated cases is present consistently and whether the magnitude of the change is comparable to that of phospholipid and cholesterol. Lipid changes were compared before and after surgical relief of the biliary obstruction. Materials and Methods
Three groups of patients were studied: (i) 15 patients (11 males and 4 females), aged 16-78 years with proven EHO; (ii) eight patients with Fredrickson Type IV hypertriglyceridemia ;(iii) 23 controls : 14 healthy adult volunteers aged 18-32 years and nine "patient controls" aged 4763 years. Liver function tests including total alkaline phosphatase, bilirubin and serum glutamic oxaloacetic transaminase were determined with an autoanalyzer. Plasma bile salts were estimated by the steroid dehydrogenase method." For lipid analysis blood was collected in EDTA without anticoagulants and lipids were extracted from the serum by the method of Folch." Unesterified and esterified cholesterol were isolated by thin layer chromatography
DECEMBER
1975
541
LIPIDS IN EXTRA HEPATIC BILIARY OBSTRUCTION
on silica gel, using a solvent system of petroleum ether, ethyl ether and glacial acetic acid, 90 : 15 : 1.5. Triglycerides were measured by the enzymatic method of Eggstein and Kreutz” which determines the glyceride glycerol fraction in serum. Plasma from nine patients was allowed to stand overnight at 4°C and any turbidity was noted. Phospholipids were determined by the method of Bartlett13 as modified by Marinetti.14 Unesterified, esterified and total cholesterol were assayed by the method of Zlatkis, Zak and Boyle.” Electrophoresis was performed with cellulose-acetate and polyacrylamide ge1.I6 Samples of whole plasma were studied for lipoprotein-X* by imrnunodiffusion” and immunoelectrophoresis’’ using 1 % agar in barbital buffer at pH 8 . 7 .
-
Normal Controls In 151 Extra Hepatic Biliary Obstruction In = 141 lype I V Hypertriqlycerideamia In 81
.
1 4w Pldsrna Lipid levels rnq per
lMml ( m a n i SEI
3w 2w
1W
Results
Diagnosis of Extra Hepatic Biliary Obstruction All patients studied had unequivocal EHO as documented clinically and biochemically and the diagnosis was confirmed in 13 out of 15 at laparotomy. Of the patients studied seven had carcinoma of the pancreas, six had cholelithiasis and two had strictures of the common bile duct. The duration of obstruction ranged from five days to 68 weeks. Liver function tests (mean SEM) were bilirubin 12.8rfr 1.98 mg/dl (normal 1 . 2 mg/dl), serum alkaline phosphatase 492k98.4 I U (normal 140 IU) and plasma total bile salts in eight of the 14 patients was 47.1 rfr 13.7 pg/ml (normal 1 pg/ml). Plasma Lipid Changes (Figure 1 and Table 1) Individual values for various lipid classes in each patient are shown in Table 1 and the mean values (rfrSEM) are shown in Figure 1. Compared to age-matched controls and patients with type IV hyperlipidaemia, plasma total and free cholesterol, phospholipid and triglyceride concentrations were elevated in most individuals. All patients except one had at least one of these parameters above normal and the mean levels were significantly elevated compared to controls ( P < 0 . OOOS), except for the unesterified cholesterol. The most striking elevation was found in the plasma triglyceride which was 280 % of control levels, compared to phospholipid and total cholesterol which were respectively 250 % and 210% of control values. The rise in plasma triglyceride was sig*Antiserum for lipoprotein-X was kindly prepared for us by Dr. D. Seidel of Medizinische Universitatsklinik, Heidelberg Germany, by a previously described method.’
Total Cholesterol
Erterified Cholesterol
Phospholipid
lriqlyceride
FIGURE 1. Plasma lipids in controls, patients with extra hepatic biliary obstruction and endogenous (Type IV) hypertriglyceridaernia.
nificantly less ( P < O.OOO5) than levels in patients with endogenous hypertrigl yceridaemia (Type IV) and total cholesterol and phospholipid concentrations were significantly greater ( P < 0.005). A marked rise in the plasma unesterified cholesterol was seen in patients with EHO. The mean ratio of free to-esterified cholesterol was 2.32 & 0.5, which was significantly higher ( P < 0.0005) than in controls (0.38 kO.01) or patients with type IV hyperlipidaemia (0.52 & 0.05)( P < 0.005).However there was no significant difference in the absolute levels of esterified cholesterol between the three groups. The mean levels of esterified cholesterol
