Amylase, lipase, pancreatic isoamylase, and phospholipase A in diagnosis of acute pancreatitis

To determine the utility of serum amylase (AMY), lipase (Lp), pancreatic isoamylase (isoA), phospholipase A (PLA), and urine AMY in the diagnosis of acute pancreatitis, samples of serum and urine were obtained on admission and every day thereafter for 5 days from 384 patients with acute abdominal pain. Diagnostic accuracy, determined as the area under the receiver operating characteristic curve, was > 0.975 for serum AMY, Lp, isoA, and urine AMY. For each of these enzymes, a threshold value (twice to sixfold the upper limit of the reference values) offering diagnostic efficiency > 95% could be determined. In contrast, accuracy and efficiency of serum PLA were low. The profiles of these enzymes in acute pancreatitis decreased in a parallel fashion over 5 days except for PLA. We conclude that diagnostic utilities are similar for serum AMY, Lp, isoA, and urine AMY for acute pancreatitis, provided that an appropriate threshold is established.

Glomerular Charge Selectivity in Primary Glomerulopathies

1. Glomerular charge selectivity was assessed using the ratio of the clearance of pancreatic isoamylase to the clearance of the more anionic salivary isoamylase (CPAm/CSAm) in 53 patients with primary glomerulopathies (minimal change nephropathy, idiopathic membranous nephropathy, IgA nephropathy) and a wide range of albumin excretion rates and in 31 healthy subjects. Fractional clearances of pancreatic and salivary isoamylases (FCPAm, FCSAm) and of albumin (FCAlb) were also measured. 2. CPAm/CSAm and FCPAm were negatively correlated with FCAlb for the whole patient group (rs = −0.56 and rs = −0.65, respectively, P < 0.0001 for both), but there was no correlation of FCSAm with FCAlb. 3. For patients with near-normal albumin excretion rates (< 100 mg/24 h), there was no difference in CPAm/CSAm between the three types of glomerulopathy or between patients and healthy subjects. 4. These data suggest that glomerular charge selectivity at the size of amylase (which is smaller than albumin) is progressively lost as albuminuria increases from normal to the nephrotic range. Size restriction progressively increases until albuminuria is very heavy. When the albumin excretion rate is near normal, charge selectivity is also normal in the three main forms of primary glomerulopathy.

Assessment of Glomerular Charge Selectivity in Man by Differential Clearance of Isoamylases

1. Glomerular charge selectivity was assessed using the ratio of the clearance of pancreatic isoamylase to the clearance of the more anionic salivary isoamylase (CPAm/CSAm) in 30 normal subjects, 14 patients with minimal proteinuria and 23 patients with heavy proteinuria due to primary glomerulopathies. Seven patients with minimal change nephropathy were studied in relapse and remission. 2. CPAm/CSAm exceeded 2.0 (range 2.1-6.1) in all normal subjects, indicating that the normal glomerular capillary wall possesses charge selectivity at the molecular size of amylase (molecular mass 56 kDa). 3. CPAm/CSAm was significantly lower in patients with heavy proteinuria than in normal subjects or patients with minimal proteinuria. CPAm/CSAm was low in patients with minimal change nephropathy in relapse and rose into the normal range with steroid-induced remission. 4. These data suggest that heavy proteinuria in primary glomerulopathies is accompanied by loss of glomerular charge selectivity. Remission of minimal change nephropathy is associated with restoration of normal charge selectivity.

Serum and Urine α — Amylase Isoenzymes levels After Operative Cholangiogram

Serum and urine total α-amylase isoenzymes values were estimated in two groups of patients, who underwent either elective cholecystectomy and operative cholangiogram (group A — 59 patients) or cholecystectomy without operative cholangiogram (group B — 68 patients). Serum and urine total α-amylase and pancreatic isoamylase (p-type) values were statistically significantly increased within the first 24 postoperative hours as compared to the preoperative levels only in group A (p < 0.05). No clinical signs of pancreatitis were observed. Serum lipase alterations did not reach any statistically significant difference in either group. It is concluded that transient hyperamylasaemia after peroperative cholangiogram may be due to a reversible chemical pancreatitis caused by the infused opacifying agent into the common bile duct.