Hiroshi Sobajima

Usefulness of a Highly Sensitive Urinary and Serum IL-6 Assay in Patients with Diabetic Nephropathy

Background/Aim: Interleukin-6 (IL-6) promotes the growth of renal mesangial cells. IL-6 may play a major role in such mesangial proliferation, but there has been little research on IL-6 in relation to diabetic nephropathy because of the difficulty in measuring urinary and serum IL-6 levels. Using a newly developed, highly sensitive IL-6 assay, we studied the relationship between serum and urinary IL-6 and diabetic nephropathy. Methods: We investigated 72 patients with type 2 diabetes. Urinary and serum IL-6 concentrations were measured using a chemiluminescent enzyme immunoassay with a detection limit of 0.11 pg/ml. Results: There was a significant increase of the serum IL-6 level as diabetic nephropathy progressed, with the level being 1.4 ± 0.3 pg/ml in patients with normal albuminuria, rising to 2.4 ± 0.6 pg/ml in patients with microalbuminuria and then to 4.4 ± 0.8 pg/ml in those having proteinuria. The serum IL-6 level was also significantly correlated with fibrinogen and aortic pulse wave velocity. The urinary IL-6 level was also significantly increased in diabetic patients as nephropathy progressed. Both serum and urinary IL-6 levels were high in the group with nephropathy, but there was no correlation between the two. Conclusion: The urinary IL-6 level seems to be a good indicator of diabetic nephropathy, and atherosclerotic changes were related to the serum IL-6 level. The serum IL-6 may, therefore, be useful in the evaluation of atherosclerosis including nephropathy.

Prevention of Experimental Acute Pancreatitis by Intraduodenal Trypsin Inhibitor in Rat

To confirm that trypsin activity is a most important initiating factor in closed duodenal loop pancreatitis in rats, we observed the course of acute pancreatitis when trypsinogen activation was inhibited by intraduodenal infusion of a potent synthetic trypsin inhibitor (TI, nafamostat mesilate) but the other conditions were left unchanged. Intraduodenal and intrapancreatic trypsinogen activation was inhibited for 16 hr after the intraduodenal infusion of the inhibitor, although elevation of serum amylase and immunoreactive trypsin and pancreatic trypsinogen remained similar both in the TI and control groups. The mortality decreased from 44% (control) to 4% (TI) at 48 hr after establishing the model. Active trypsin in duodenal reflux is an initiating factor for further development of acute pancreatitis in the closed loop model, and inhibition of the initial activation of trypsinogen has a favorable effect on acute pancreatitis even if other deleterious factors remain unchanged.

Serum pancreatic stone protein in pancreatic diseases.

SummarySerum pancreatic stone protein (PSP) was determined in sera of pancreatic and nonpancreatic diseases using enzyme immunoassay specific to human PSP to study the diagnostic and pathophysiological significance of PSP. Serum PSP in acute pancreatitis (mean±SD=1075.4±2849.1 ng/mL,n=33) was significantly higher than that in controls (78.6±31.8 ng/mL,n=37,p<0.01), chronic pancreatitis (156.8±82.8 ng/mL,n=32,p<0.05), and pancreatic cancer (148.468.8 ng/mL,n=26,p<0.05). No significant difference was found between noncalcified and calcified chronic pancreatitis. Serum PSP levels were significantly higher in chronic renal failure under hemodialysis (1796.0±1492.9 ng/mL) than in other diseases such as peptic ulcer, liver cirrhosis, gallstone, and diabetes mellitus. Low but significant correlation was obtained between serum PSP and serum immunoreactive trypsin (r=0.22,p<0.05). Increased serum PSP levels in acute pancreatitis and chronic renal failure suggest that serum PSP levels reflect reflux from pancreatic secretion, release from damaged pancreatic acinar cells, or retention in circulation, and can be useful for diagnosis of acute pancreatitis, but not chronic calcified pancreatitis.

Effect of a new synthetic trypsin inhibitor on taurocholate-induced acute pancreatitis in rats

The effect of a novel synthetic trypsin inhibitor, 4-sulfamoylphenyl 4-guanidinobenzoate methanesulfonate (ONO-3307), on severe acute pancreatitis was studied by changing its timing, frequency, and dose in trypsintaurocholate- induced acute experimental pancreatitis in rats. Rats were divided into four groups according to difference of ONO-3307 administration: group A, 2 md0.5 ml of ONO-3307 S.C. I h before and after induction of pancreatitis; group B, 2 md0.5 ml S.C. 1 and 3 h after; group C, 4 mg/l ml S.C. 1 h before; group D, 4 mg/1 ml s.c. 1 h after. The survival rate at 24 h was significantly improved in group A (75% in A vs. 17% in control; p <0.01) and in group B (57 vs. 29%; p <0.051, but not in group C or D. Amylase and immunoreactive trypsin in serum and ascites of the treated were significantly lower than those of controls in both groups A and B. The survival rates were improved dose dependently when ONO-3307 was administered 1 h before and after induction of pancreatitis. ONO-3307 showed favorable effects on the initial stage of severe acute pancreatitis when given in divided doses to maintain the effective serum levels.

The diagnostic value of serum pancreatic phospholipase A2 (PLA2) in pancreatic diseases

SummaryThe diagnostic significance of serum immunoreactive pancreatic phospholipase A2 (PLA2) was studied in 119 patients with pancreatic disease, 200 with various non-pancreatic disease, and 203 healthy controls using radioimmunoassay (RIA) specific to human pancreatic PLA2. This newly developed RIA using monoclonal antibody was satisfactorily sensitive and reliable. Serum PLA2 was elevated in all six patients with acute pancreatitis. Frequency of abnormal serum PLA2 levels was 60% in chronic pancreatitis (n=52) and 67% in pancreatic cancer (n=61). Serum PLA2 levels were low in chronic pancreatitis with severe exocrine insufficiency and advanced pancreatic cancer. In chronic pancreatitis, patients with low serum PLA2 level showed lower enzyme output in secretin test than patients with normal or high serum PLA2 level. Frequency of abnormal PLA2 levels was 27% in non-pancreatic disease and, in particular, patients with renal failure showed high PLA2 levels. Sensitivity (62%) and efficiency (69%) of serum PLA2 assay in pancreatic disease were superior to those of amylase. In conclusion, serum PLA2 determination using RIA was useful for the diagnosis of acute pancreatitis by high serum PLA2 levels and the diagnosis of severe exocrine pancreatic insufficiency by low serum PLA2 levels.

Elevation of serum phospholipase A2 in patients at an intensive care unit

SummaryTo evaluate the organ specificity of pancreatic phospholipase A2 (PLA2) and the diagnostic value of the elevation of serum PLA2 levels in patients with serious diseases not involving the pancreas, we studied the organ distribution of PLA2 in autopsy specimens and serum level of PLA2 in patients who required admission to an intensive care unit (ICU). PLA2 was measured by a specific radioimmunoassay (RIA), using monoclonal antibody against human pancreatic PLA2. Organ distribution of PLA2 revealed that the pancreas showed a much higher content of pancreatic PLA2 immunoreactivity than any other organ. An abnormally high value of serum PLA2 was observed in 18 of 30 patients (60%) at ICU. Both serum PLA2 and pancreatic isoamylase were elevated in 11 patients (37%). Of 11 patients with hyperphospholipasemia and hyperamylasemia, serum creatinine was elevated in five patients and blood urea nitrogen in nine patients. Serum PLA2 levels did not always rise comparably to serum creatinine and blood urea nitrogen levels. Serum PLA2 values showed the best correlation with serum lactate dehydrogenase levels among routine blood-chemistry tests. The elevation of serum PLA2 was ascribable to renal dysfunction or ischemic pancreatic damage secondary to circulatory collapse with multiple organ failure.

Monitoring Serum Tryptic Activity and Effect of Trypsin Inhibitor on Rat Acute Pancreatitis

The effect of a novel synthetic trypsin inhibitor, 4-(2-succinimidoethylthio)-phenyl 4-guanidinobenzoate methanesulfonate (E3123), on severe acute pancreatitis was studied in trypsin-taurocholate-induced acute experimental pancreatitis in rats. Rats were divided into four groups according to difference of subdivided doses of E3123 with fixing the total dose at 3 mg/kg body weight. Group A: 1.5 mg/kg of E3123 subcutaneously (SC) each at 1 h before and after induction of pancreatitis. Group B: 1 mg/kg SC each at 1 h before, 1 and 3 h after induction. Group C: 1.5 mg/kg SC each at 1 and 3 h after induction. Group D: 1.5 mg/kg SC each at 3 and 5 h after induction of pancreatitis. The survival rate at 24 h was significantly improved in group B (77% in group B, vs. 36% in paired control; p < 0.01) and in group C (70 vs. 38%; p < 0.05), but not in group A or D. Residual tryptic activity of serum alpha 2-macroglobulin trypsin complex (alpha 2M-TRY) was reduced after the injection of E3123 though immunoreactive trypsin remained unchanged in the early phase of pancreatitis. The reduction of alpha 2M-TRY reflected the inhibitory capacity of E3123 in plasma. E3123 showed favorable effects on the initial stage of severe acute pancreatitis and the effects were probably based on the inhibition of alpha 2M-TRY activity in serum.

Longitudinal changes of plasma pancreatic enzymes and hormones in experimental pancreatolithiasis in dogs

Plasma pancreatic enzymes and hormones were longitudinally observed after producing partial obstruction of the major pancreatic duct in dogs to study an initial state of chronic pancreatitis or pancreatolithiasis. Fasting plasma immunoreactive cationic trypsin was elevated during the first six months and then decreased in a subgroup with pancreatic opposite at the end of the 12-month period. Similar but less prominent changes were found in fasting plasma immunoreactive pancreatic polypeptide (IRPP). Plasma amylase, glucose, or immunoreactive insulin or glucagon (IRG) show no significant variation. Plasma IRG and IRPP responses to intravenous insulin were reduced in the subgroups with marked pancreatic changes towards the end of the 12-month period. These results suggest that plasma pancreatic enzymes and hormones remain elevated as long as pancreatic damage is mild and then start to decline as the damage progresses in chronic pancreatitis or pancreatolithiasis.

Serum α2‐macroglobulin–trypsin complex and early recognition of severe acute pancreatitis after endoscopic retrograde pancreatography

Serum α2‐macroglobulin‐trypsin complex (α2M‐T) was measured to differentiate the elevation of serum pancreatic enzymes caused by severe acute pancreatitis from simple elevation after endoscopic retrograde pancreatography (ERP). A patient with severe acute pancreatitis demonstrated marked elevation of serum α2M‐T. In patients without severe acute pancreatitis, serum αM‐T did not rise in spite of elevated serum pancreatic enzymes. In conclusion, abdominal pain with elevated serum α2M‐T can be an early diagnostic clue to severe acute pancreatitis after ERP.

Protective effects of a prostaglandin E1 oligomer on taurocholate-induced rat pancreatitis

Effects of prostaglandin E (PGE) on acute pancreatitis have been controversial. This study shows the effects of PGE1 oligomer, MR‐356, on trypsin‐taurocholate‐induced acute pancreatitis in rats. Divided intraperitoneal doses of 0.6 mg/rat were administered, which increased 24 h survival rates when the oligomer was given both at 1 h before and after (group A) and immediately and 3 h after (group B) induction of pancreatitis. In group A MR‐356 significantly improved the survival rates at 18 h (94 vs 61%, P < 0.05) and 24 h (68 vs 33%, P <0.05) when compared with controls. MR‐356 improved the survival rates dose‐dependently up to 0.6 mg/rat when given by the same protocol of group A. In group B MR‐356 also improved the survival rate (72 vs 39%, P < 0.05) only at 24 h, while other parameters failed to improve. The present results suggest that the PGE1 oligomer may play a beneficial role in bile‐induced pancreatitis, probably through its proposed effects of stabilization of lysosomal membranes, maintenance of microcirculation and inhibition of protease in the pancreas.