Familial hyperamylasemia

Clinical applications of amylase: Novel perspectives

BACKGROUND

Amylase was the first enzyme to be characterized, and for the previous 200 years, its clinical role has been restricted to a diagnostic aid. Recent interface research has led to a substantial expansion of its role into novel, viable diagnostic, and therapeutic applications to cancer, infection, and wound healing. This review provides a concise "state-of-the-art" overview of the genetics, structure, distribution, and localization of amylase in humans.

METHOD

A first-generation literature search was performed with the MeSH search string "Amylase AND (diagnost∗ OR therapeut$)" on OVIDSP and PUBMED platforms. A second-generation search was then performed by forward and backward referencing on Web of Knowledge™ and manual indexing, limited to the English Language.

RESULTS

"State of the Art" in amylase genetics, structure, function distribution, localisation and detection of amylase in humans is provided. To the 4 classic patterns of hyperamylasemia (pancreatic, salivary, macroamylasemia, and combinations) a fifth, the localized targeting of amylase to specific foci of infection, is proposed.

CONCLUSIONS

The implications are directed at novel therapeutic and diagnostic clinical applications of amylase such as the novel therapeutic drug classes capable of targeted delivery and "smart release" in areas of clinical need. Future directions of research in areas of high clinical benefit are reported.

Establishment of biochemistry reference values for healthy Tanzanian infants, children and adolescents in Kilimanjaro Region

OBJECTIVE

To establish common biochemistry reference intervals for Tanzanian infants, children and adolescents living in the Kilimanjaro Region.

METHODS

We recruited healthy, HIV-uninfected Tanzanian infants, children and youth between the ages of 1 month and 17 years from local schools and clinics to participate in this study. Only afebrile children without signs of physical or chronic illness were enrolled. Nonparametric methods were used to determine 95% reference limits and their 90% confidence intervals, with outliers removed by the Tukey method.

RESULTS

A total of 619 healthy infants, children and adolescents were enrolled into the study. Twenty-three biochemistry parameters were measured. Compared to US reference intervals, several of the biochemistry parameters showed notable differences, namely alkaline phosphatase, phosphorus, amylase and lipase. Comparing our data to the US National Institutes of Health (NIH) Division of AIDS (DAIDS) grading criteria for classification of adverse events, we found that for selected parameters, up to 15% of infants or children in certain age groups would have been categorised as having an adverse event as defined by DAIDS.

CONCLUSIONS

Our study further confirms the need to use locally established reference intervals to define reference laboratory parameters among children in Africa, rather than relying on those derived from US or European populations. To our knowledge, this study provides the first set of locally validated biochemistry reference ranges for a paediatric population in Tanzania.

Two rare cases of benign hyperlipasemia in children

Gullo’s syndrome is a newly identified condition characterized by a chronic elevation of pancreatic amylase and/or lipase in the absence of pancreatic disease. Until now, only one case of benign isolated hyperlipasemia in children has been recorded. We describe two children with benign and not familial increase of serum lipase. Case 1: a six year old girl presented with occasional discovery of serum lipase elevation. Medical history was silent for pancreatic hyperenzymemia. The screening for possible causes for elevated lipase (genetic, autoimmune and infectious diseases) was normal. The serum lipase increased three fold over the upper limit (193 U/L; reference range 0-60 U/L), with daily fluctuation of values. Both ultrasound scan and magnetic resonance imaging were normal. The genetic mutation associated with chronic pancreatitis was negative. We followed up this patient for two years with blood tests every six months and she did not show any signs or symptoms of pancreatic disease, except for the high level of lipase serum. Case 2: an eight year old girl complained of nausea, vomiting and severe abdominal pain in the epigastric region after eating for the last two weeks. Full blood count, electrolytes, C-reactive protein, liver and renal function were normal. Serum lipase was 96 U/L (reference range 0-60 U/L). The screening for the possible causes of pancreatic disease was negative. Endoscopy of the upper gastrointestinal tract, ultrasound, computed tomography scan and magnetic resonance imaging were normal. One year after the presentation of the symptoms, the patient became asymptomatic although the level of serum lipase continued to be high.

Benign pancreatic hyperenzymemia in children

One of us recently described chronic pancreatic hyperenzymemia in the absence of pancreatic or other disease in adult subjects. The aim of the present study was to describe this form of pancreatic hyperenzymemia in children. The study involved 15 children with this condition seen from September 1996 to December 2004. After initial evaluation, each child was seen by us once annually until the end of the study. Each check-up included serum amylase (normal values 20-220 IU/L), pancreatic isoamylase (17-115 IU/L) and lipase (24-270 IU/L) determinations as well as abdominal ultrasound. In six children, fecal elastase was also determined. At the initial assessment, 13 of the 15 children had abnormal serum increases in all three enzymes, one showed an increase only in lipase, and in the remaining child all three enzymes were present in normal concentrations. These latter two children had had abnormally elevated levels of all enzymes at the examination performed before this study began. During follow-up, enzyme concentrations remained abnormally elevated, although with wide fluctuations and transient normalizations. Considering the highest values of enzymes found in the various examinations performed during this study, the increase over the upper normal limit was in the range of 1.5- to 5.2-fold for amylase, 2.2-to 8.0-fold for pancreatic isoamylase, and 2.0- to 15.4-fold for lipase. Fecal elastase was normal in the six children in whom it was measured. No child had evidence of pancreatic or other disease, either at initial evaluation or during follow-up. The results of this study describe benign pancreatic hyperenzymemia in children. Although it is a benign condition, awareness of it is important to avoid unnecessary concern and multiple diagnostic procedures.