Br. J. Surg. 1991, Vol. 78, May, 568-571
S. M. Megison, C. W. Dunn, J. W. Horton and H. Chao Department of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA Correspondence to: Dr J. W. Horton
Effects of relief of biliary obstruction on mononuclear phagocyte system function and cell mediated immunity Obstructive jaundice causes depression of immune system function but it is unclear at present how rapidly immunefunction recovers after relief of biliary obstruction. To address this issue, we studied 218 Sprague-Dawley rats with common bile duct obstruction. Mononuclear phagocyte function, cell mediated immune function, portal-systemic shunt fraction, liver function tests, and liver histology were evaluated in normal (sham) rats, obstructed rats, and at weekly intervals after relief of biliary obstruction. Hepatic uptake of radiolabelled bacteria was 82 per cent in sham rats and 66 per cent in rats 21 days a f e r CBD obstruction (P < 0.05). Phagocytic activity returned to normal within 7 days ufter choledochoduodenostomy. Cell mediated immunity, measured by skin graft rejection, was significantly prolonged in the obstructed group (P < 0.05) but had returned to normal 7 days after biliary diversion. Return of hepatocellular function, as measured by liver junction tests, paralleled recovery of immune function. This study demonstrates prompt recovery of the immune system after internal biliary drainage for obstructive jaundice. This finding is in contrast to previous studies that demonstrated persistent immune suppression months after biliary diversion. These data may have implications concerning the usefulness of internal biliary drainage before surgery in patients with obstructive jaundice.
T h e patient with biliary obstruction, affected by malnutrition, sepsis o r malignancy, poses a difficult treatment p r o b l e m and represents a significant challenge t o t h e clinician. Surgery t o resect o r bypass t h e obstructing lesion is associated with a significant incidence of complications. Renal failure, gastrointestinal haemorrhage, w o u n d dehiscence, fistula formation and sepsis a r e m o r e likely t o o c c u r after surgery performed in t h e presence of biliary obstruction"'. T h e immunosuppressive effects of obstructive j a u n d i c e a r e well defined3-9 a n d widely accepted. Recovery of i m m u n e function after biliary drainage, however, is n o t clearly documented. T h i s s t u d y is designed t o characterize t h e effects of obstructive j a u n d i c e and subsequent relief of biliary obstruction o n m o n o n u c l e a r phagocyte function and o n cell mediated immunity.
Materials and methods In all 218 adult male Sprague-Dawley rats (30WOOg) were entered into the study (Table f ) , adhering to regulations set forth by the Southqestern Medical Center Institutional Review Board for Animal Research. Under methoxyflurane inhalation anaesthesia, 171 rats underwent laparotomy with common bile duct ligation and division. Forty-seven rats had laparotomy with isolation and manipulation of the common bile duct without ligation and served as sham operated controls. At 21 days after bile duct obstruction, choledochoduodenostomy was performed in 122 rats to achieve biliary diversion as described by Ryan et a / , " , Rats received cefazolin 17 mg/kg just before laparotomy and were resuscitated with Ringer's lactate 50 ml/kg subcutaneously immediately after surgery. The 49 rats with common duct ligation but without biliary diversion were evaluated 21 days after ligation as obstructed controls (CDL group). Cell mediated immunity and function in the mononuclear phagocyte system were evaluated in sham controls, obstructed controls, and at weekly intervals after biliary diversion to document immune suppression and subsequent return of immune function. Portal-systemic shunting was measured in each group to determine how changes in hepatic portal flow affected
measurement of phagocytic function. Serum liver function tests and liver histology were evaluated in each group. Mononuclear phagocyte system ,function To evaluate phagocytic activity in the mononuclear phagocyte system, rats were injected with radiolabelled Eschuichiu coli. E. coli were prepared by incubation with '5Se-selenomethionine in methionine-free broth to allow incorporation of the radioisotope. This technique produced an injectate of 4.6 x lo9 live E. coli per ml with one of every 70 bacteria radiolabelled. An innoculum of 1 ml was injected into the lateral tail vein of each animal on the day designated for bacterial challenge (sham rats, C D L rats and rats 7,14,21 or 28 days after biliary diversion). Animals were killed 30 min after injection. Organs comprising the reticuloendothelial system (liver, lungs and spleen) were harvested and radioactivity was determined using a y-scintillation counter (Packard, model 5320, Richardson, Texas, USA). Relative phagocytic uptake of the injected bacteria was calculated from the total radioactivity of the injectate and the radioactivity of each organ:
radioactivity in individual organ x 100 Percentage bacterial uptake=^--total radioactivity injected Previous studies by Dunn et a/.3 using this technique demonstrated that more than 98 per cent of injected bacteria were cleared within 30 min of injection and that phagocytic function was significantly depressed in the liver of obstructed animals. This technique allows recovery of 94 per cent of the injectate by harvesting liver, lungs and spleen3. Determination o f portal-systemic shunt Because biliary obstruction leads to cirrhosis, portal hypertension and portal-systemic shunting, we were concerned that decreased hepatic uptake of bacteria may reflect decreased bacterial delivery to the liver because of decreased blood flow, rather than truly impaired phagocytic function. Portal systemic shunting was measured in separate animals in each treatment group (sham, CDL, and 7, 14 and 28 days after diversion). According to the method described by Chojkier and Groszmann", laparotomy was performed and each spleen was injected
~568
0007~1323/91/050568-04
()
1991 Butterworth-Heinemann Ltd
Immune function after biliary diversion: S. M . Megison et al. Table 1 Animul utilization
218 rats 47 shams
7 shams for liver function studies and histology 10 shams for portal flow studies 16 shams for bacterial uptake studies 14 shams for skin grafting
171 rats Common duct ligation 49 rats 12 C D L rats C D L group 10 C D L rats 14 C D L rats histology 13 C D L rats 122 rats Choledochoduodenostomy 39 rats 15 rats 7 days after 10 rats biliary diversion 5 rats 9 rats 25 rats 14 days after biliary diversion 25 rats 21 days after biliary diversion 29 rats 28 days after biliary diversion
4 rats 42 days after biliary diversion
for for for for
for bacterial uptake studies for portal flow studies for liver function studies and for skin grafting
bacterial uptake studies portal flow studies liver function studies and histology skin grafting
10 rats for bacterial uptake studies 10 rats for portal flow studies 5 rats for liver function studies and histology 12 rats for bacterial uptake studies 13 rats for skin grafting
5 rats 5 rats 5 rats 14 rats
for bacterial uptake studies for portal flow studies for liver function studies and histology for skin grafting
4 rats for liver function studies and histology
CDL, common duct ligation
Statistical analysis Statistical analysis of the resulting data was completed using the Student Neuman Keuls test for comparison of multiple independent groups. Results are expressed as the mean(s.e.m.).
Results Mononuclear phagocyte system ,function Sham rats, those with an intact biliary system, demonstrated 82 per cent uptake of injected E. coli in the liver, 4 per cent in the lung and 12 per cent in the spleen. Rats with common bile duct obstruction of 3 weeks duration (CDL) demonstrated a decrease in hepatic uptake (from 82 per cent to 66 per cent) with a reciprocal increase in pulmonary uptake (from 4 per cent to 22 per cent). After choledochoduodenostomy, hepatic and pulmonary uptake returned to preobstructive levels within 7 days of diversion and remained at this level in groups studied 14, 21 and 28 days after biliary diversion (Table 2). Splenic uptake was not changed after ductal ligation or diversion. The differences in hepatic and pulmonary uptake values for sham, CDL, and shunted groups were statistically significant ( P
S. M. Megison, C. W. Dunn, J. W. Horton and H. Chao Department of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, USA Correspondence to: Dr J. W. Horton
Effects of relief of biliary obstruction on mononuclear phagocyte system function and cell mediated immunity Obstructive jaundice causes depression of immune system function but it is unclear at present how rapidly immunefunction recovers after relief of biliary obstruction. To address this issue, we studied 218 Sprague-Dawley rats with common bile duct obstruction. Mononuclear phagocyte function, cell mediated immune function, portal-systemic shunt fraction, liver function tests, and liver histology were evaluated in normal (sham) rats, obstructed rats, and at weekly intervals after relief of biliary obstruction. Hepatic uptake of radiolabelled bacteria was 82 per cent in sham rats and 66 per cent in rats 21 days a f e r CBD obstruction (P < 0.05). Phagocytic activity returned to normal within 7 days ufter choledochoduodenostomy. Cell mediated immunity, measured by skin graft rejection, was significantly prolonged in the obstructed group (P < 0.05) but had returned to normal 7 days after biliary diversion. Return of hepatocellular function, as measured by liver junction tests, paralleled recovery of immune function. This study demonstrates prompt recovery of the immune system after internal biliary drainage for obstructive jaundice. This finding is in contrast to previous studies that demonstrated persistent immune suppression months after biliary diversion. These data may have implications concerning the usefulness of internal biliary drainage before surgery in patients with obstructive jaundice.
T h e patient with biliary obstruction, affected by malnutrition, sepsis o r malignancy, poses a difficult treatment p r o b l e m and represents a significant challenge t o t h e clinician. Surgery t o resect o r bypass t h e obstructing lesion is associated with a significant incidence of complications. Renal failure, gastrointestinal haemorrhage, w o u n d dehiscence, fistula formation and sepsis a r e m o r e likely t o o c c u r after surgery performed in t h e presence of biliary obstruction"'. T h e immunosuppressive effects of obstructive j a u n d i c e a r e well defined3-9 a n d widely accepted. Recovery of i m m u n e function after biliary drainage, however, is n o t clearly documented. T h i s s t u d y is designed t o characterize t h e effects of obstructive j a u n d i c e and subsequent relief of biliary obstruction o n m o n o n u c l e a r phagocyte function and o n cell mediated immunity.
Materials and methods In all 218 adult male Sprague-Dawley rats (30WOOg) were entered into the study (Table f ) , adhering to regulations set forth by the Southqestern Medical Center Institutional Review Board for Animal Research. Under methoxyflurane inhalation anaesthesia, 171 rats underwent laparotomy with common bile duct ligation and division. Forty-seven rats had laparotomy with isolation and manipulation of the common bile duct without ligation and served as sham operated controls. At 21 days after bile duct obstruction, choledochoduodenostomy was performed in 122 rats to achieve biliary diversion as described by Ryan et a / , " , Rats received cefazolin 17 mg/kg just before laparotomy and were resuscitated with Ringer's lactate 50 ml/kg subcutaneously immediately after surgery. The 49 rats with common duct ligation but without biliary diversion were evaluated 21 days after ligation as obstructed controls (CDL group). Cell mediated immunity and function in the mononuclear phagocyte system were evaluated in sham controls, obstructed controls, and at weekly intervals after biliary diversion to document immune suppression and subsequent return of immune function. Portal-systemic shunting was measured in each group to determine how changes in hepatic portal flow affected
measurement of phagocytic function. Serum liver function tests and liver histology were evaluated in each group. Mononuclear phagocyte system ,function To evaluate phagocytic activity in the mononuclear phagocyte system, rats were injected with radiolabelled Eschuichiu coli. E. coli were prepared by incubation with '5Se-selenomethionine in methionine-free broth to allow incorporation of the radioisotope. This technique produced an injectate of 4.6 x lo9 live E. coli per ml with one of every 70 bacteria radiolabelled. An innoculum of 1 ml was injected into the lateral tail vein of each animal on the day designated for bacterial challenge (sham rats, C D L rats and rats 7,14,21 or 28 days after biliary diversion). Animals were killed 30 min after injection. Organs comprising the reticuloendothelial system (liver, lungs and spleen) were harvested and radioactivity was determined using a y-scintillation counter (Packard, model 5320, Richardson, Texas, USA). Relative phagocytic uptake of the injected bacteria was calculated from the total radioactivity of the injectate and the radioactivity of each organ:
radioactivity in individual organ x 100 Percentage bacterial uptake=^--total radioactivity injected Previous studies by Dunn et a/.3 using this technique demonstrated that more than 98 per cent of injected bacteria were cleared within 30 min of injection and that phagocytic function was significantly depressed in the liver of obstructed animals. This technique allows recovery of 94 per cent of the injectate by harvesting liver, lungs and spleen3. Determination o f portal-systemic shunt Because biliary obstruction leads to cirrhosis, portal hypertension and portal-systemic shunting, we were concerned that decreased hepatic uptake of bacteria may reflect decreased bacterial delivery to the liver because of decreased blood flow, rather than truly impaired phagocytic function. Portal systemic shunting was measured in separate animals in each treatment group (sham, CDL, and 7, 14 and 28 days after diversion). According to the method described by Chojkier and Groszmann", laparotomy was performed and each spleen was injected
~568
0007~1323/91/050568-04
()
1991 Butterworth-Heinemann Ltd
Immune function after biliary diversion: S. M . Megison et al. Table 1 Animul utilization
218 rats 47 shams
7 shams for liver function studies and histology 10 shams for portal flow studies 16 shams for bacterial uptake studies 14 shams for skin grafting
171 rats Common duct ligation 49 rats 12 C D L rats C D L group 10 C D L rats 14 C D L rats histology 13 C D L rats 122 rats Choledochoduodenostomy 39 rats 15 rats 7 days after 10 rats biliary diversion 5 rats 9 rats 25 rats 14 days after biliary diversion 25 rats 21 days after biliary diversion 29 rats 28 days after biliary diversion
4 rats 42 days after biliary diversion
for for for for
for bacterial uptake studies for portal flow studies for liver function studies and for skin grafting
bacterial uptake studies portal flow studies liver function studies and histology skin grafting
10 rats for bacterial uptake studies 10 rats for portal flow studies 5 rats for liver function studies and histology 12 rats for bacterial uptake studies 13 rats for skin grafting
5 rats 5 rats 5 rats 14 rats
for bacterial uptake studies for portal flow studies for liver function studies and histology for skin grafting
4 rats for liver function studies and histology
CDL, common duct ligation
Statistical analysis Statistical analysis of the resulting data was completed using the Student Neuman Keuls test for comparison of multiple independent groups. Results are expressed as the mean(s.e.m.).
Results Mononuclear phagocyte system ,function Sham rats, those with an intact biliary system, demonstrated 82 per cent uptake of injected E. coli in the liver, 4 per cent in the lung and 12 per cent in the spleen. Rats with common bile duct obstruction of 3 weeks duration (CDL) demonstrated a decrease in hepatic uptake (from 82 per cent to 66 per cent) with a reciprocal increase in pulmonary uptake (from 4 per cent to 22 per cent). After choledochoduodenostomy, hepatic and pulmonary uptake returned to preobstructive levels within 7 days of diversion and remained at this level in groups studied 14, 21 and 28 days after biliary diversion (Table 2). Splenic uptake was not changed after ductal ligation or diversion. The differences in hepatic and pulmonary uptake values for sham, CDL, and shunted groups were statistically significant ( P
