Abstracts of the 22nd Symposyum Croatian Society of Medical Biochemists

Orjena Žaja Franulović*, Tatjana Lesar

 

Born helpless and utterly dependent, the infant undergoes a remarkable transformation before reaching adulthood. This transformation involves not only physical growth and maturation but also a dazzling array of complex developmental events impacting on each organ system and on the child as a whole. Developmental phenomena can be important determinants of the young patient’s response to disease and to its management. The need for an understanding of the developing child as a whole is inescapable if one is to deal effectively with any pediatric patient. Rapid postnatal growth is accompanied by a sequence of other maturational changes. As the child grows and matures, the digestive tract is undergoing a complex array of developmental events too. These phenomena can have a significant impact on normal healthy function and the young patient’s response to disease. The intestinal tract is an intriguing organ with multiple functions. Primary nutritional functions, water and nutrient absorption, electrolyte and oligoelements homeostasis, are cornerstones that can ensures normal growth. At the other hand, the intestinal mucosa have a complex immune functions and plays an important role in the secretion of various hormones and transmitters. There are three very different and complex organs that accomplish these tasks of gastrointestinal tract: stomach, intestine and pancreas. Laboratory tests for functional disorders of this organs are very important in diagnostic workup, especially for malapsorption syndrome that is one of the most frequent disorder that pediatric gastroenterologist meets in his everyday practice. In this lecture, beside the physiological feature of child’s intestinal tract, we will overview some of the most frequent diseases that can lead to malapsorption or growth failure, such as celiac disease, inflammatory bowel disease or pancreatic exocrine insufficiency and the importance of some specific laboratory tests that can help us in establishing correct diagnosis.

Key words: pediatric gastroenterology; malapsorption syndrome; inflammatory bowel disease

 

Jasna Obuljen

 

The term gastrointestinal food allergy refers to the adverse immune reaction that develops in response to the ingestion of a concrete type of food with harmful manifestation on gastrointestinal system. Food allergy in childhood is more common than in adults, with prevalence reported 6-8% in infants in the first year of life, compared to 1-2% in adults. These reactions can be classified in 3 main types: immunoglobulin E (IgE) mediated (immediate gastrointestinal hypersensitivity and oral allergy syndrome), „mixed“ involving some IgE and non-IgE components (eosinophilic allergic esophagitis, eosinophilic allergic gastroenteritis and eosinophilic gastritis) and non-IgE-mediated or T-cell-mediated allergic gastrointestinal disorders (dietary protein enteropathy, protein-induced enterocolitis, proctitis).

Regardless of the immune mechanism involved, the different presentations of gastrointestinal hypersensitivity are clinically similar, although they tend to differ in terms of the timing of onset, severity and duration, including diarrhea, vomiting, dysphagia, constipation or gastrointestinal bloodloss.

In daily practice, allergy diagnostics starts with the skin prick test and definition of the type of allergic reaction by determination of concentration of total IgE and number of eosinophil granulocytes. The next step is determination of allergen-specific IgE (sometimes allergen-specific IgG), tryptase, eosinophil cationic protein and basophil activation tests. If necessary, celiac disease panel testing is performed – anti-gliadin antibodies AGA-IgA, -IgG, anti-endomysial antibodies (EMA-IgA) and human tissue transglutaminase IgA (IgA-tTG).

Yet, diagnosis of allergy with gastrointestinal manifestations is very complex, the only gold standard is still oral challenge test. This lecture reviews diagnostic value of standard tests for gastrointestinal hypersensitivity, with an emphasis on child population.

Key words: food allergy; allergen-specific IgE; anti-endomysial antibodies; transglutaminase immunoglobulins; anti-gliadin antibodies

 

Irena Linarić

 

In recent years laboratory medicine is continuously changing and developing with introducing new advanced medical knowledge and technologies.

Referral Centar for Pediatric Gastroenterology and Nutrition,Children’s Hospital Zagreb is leading center for treating children with severe gastrointestinal diseases, and it is extremely important to choose high quality and cost-effective gastrointestinal function analyses.

Laboratory diagnostics in Gastroenterology includes specific screening programs using modern methods to detect new biomarkers in stool. For some time, we have been using two biomarkers in our pediatric laboratory practice: pancreatic (fecal) elastase-1, and fecal calprotectin.

Pancreatic elastase-1 (E1) is a human and pancreas specific serine protease synthetized by acinar cells and it is involved in the hydrolysis of peptide bonds. The fecal E1 test is simple, non-invasive and easy to perform especially in children; it measures how well the pancreas is functioning. Results of this test give a good indication of exocrine pancreatic status in pediatric patients with hypotrophy, cystic fibrosis and chronic pancreatitis.

Calprotectin is an abundant neutrophil protein found in both plasma and stool that plays a key role as a marker of infection and intestinal inflammation, especially in inflammatory bowel disease (IBD). Fecal calprotectintest is reliable and useful for distinguishing between non-inflammatory bowel disorders (e. g. irritable bowel disease) and IBD (e.g. ulcerative colitis and Chron’s disease). Calptotectin is regularly raised in active IBD and is also used to monitor therapy.

Although no single ideal marker exits; calprotectin shows promise in diagnosing inflammatory disease, monitoring disease activity and predicting relapse.

Key words: pancreatic elastase; calprotectin; biomarkers

 

Andrea Tešija Kuna

 

Inflammatory bowel disease (IBD), a term that refers to Crohn’s disease (CD) and ulcerative colitis (UC), develops as a consequence of the aberrant immunologic response of the mucosal immune system toward normal luminal flora. It is most likely due to the compromised integrity of the intestinal epithelium or defect in the mucosal immune system. Susceptibility to IBD depends on the combined effect of genetic and environmental factors. The diagnosis of IBD and distinction between two major forms of the disease depends on clinical history, physical findings, endoscopic, radiologic and histological features. In the subpopulation of patients with IBD limited to the colon, distinction between UC and CD is difficult and serologic profile can help in differential diagnosis. Several serologic markers have been associated with IBD but only two are currently being used in routine: perinuclear-staining antineutrophil cytoplasmic autoantibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA). pANCA has been observed in majority of patients with UC (60-80%) but also in subset of CD patients (10-30%) with UC-like phenotype. Recent evidence suggests DNA-bound lactoferrin as the major target of UC-associated ANCA. CD has been associated with ASCA antibodies (in up to 70% of patients) but also with highly specific pancreatic autoantibodies (PAB) which are present in about one third of CD patients. Recently, the major zymogen granule membrane glycoprotein 2 (GP2) was identified as PAB target autoantigen. Another promising autoantigen in CD is recently identified ubiquitination factor E4A (UBE4A) and the presence of these autoantibodies showed significant association with disease activity and outcome.

Key words: autoantibodies; imunological markers; bowel diseases

 

Deana Šturm

 

Over the past decades, the incidence of colorectal cancer is increasing. Malignant disease causes deep changes in the haemostasis system, which is important to understand the treatment and prevention of complications, especially in patients undergoing surgery. Identifying hypercoagulability can significantly affect the choice of treatment and reduce morbidity. Our study was conducted on 100 patients with rectal cancer, mean age 60 years. We have investigated perioperative changes in plasma values of tests of hemostasis antithrombin III, protein C, protein S, plasminogen activator inhibitor-1 (PAI-1), alpha-2-antiplasmin, D-dimer, plasminogen. The study included only the patients with no previous history of deep vein thrombosis (DVT) or at no risk of developing venous thromboembolism (VTE). All patients underwent the same surgical procedure and all had confirmed adenocarcinoma. Based on histological findings were classified by increasing Dukes classification from A to C. Only plasma levels of PAI-1 in the group with Dukes A were confirmed to be statistically higher than in Dukes B and C, showing no correlation with tumor size. The correlation of plasma PAI-1 and antigen PAI-1 levels in tumor tissues remains controversial. As there is a known effect of PAI-1 on angiogenesis, the results for Dukes A could be related with a more aggressive tumor type.

Key words: rectal carcinoma; haemostatic tests; plasminogen activator inhibitor-1

 

Zvjezdana Špacir-Prskalo

 

Monoclonal antibodies are used to detect serum antigens associated with specific malignancies. Tumor markers do not have sufficient sensitivity or specificity screening pourposes. They are most useful in monitoring response to therapy and detecting early relapse.

Although the CA 19-9 marker was first seen in colorectal cancer, it has become a useful marker for pancreatic cancer. About 85% of people with pancreatic cancer have elevated levels of CA 19-9 (higher than 37 U/mL). The higher the level, the more likely the disease has metastasized. It is also useful in patient follow-up. Patients whose CA 19-9 levels drop to normal after surgery, have a much better outlook than those whose CA 19-9 remains elevated after surgery.

No marker has been developed specifically for stomach (gastric) cancer. Some other digestive cancer markers may be elevated, particularly CEA. If CEA levels are elevated, it can be watched if metastatic gastric cancer is being treated. An elevated CEA before surgery may indicate a poor prognosis. After surgery, the CEA should return to normal levels in 4-6 weeks if the cancer has been entirely removed.

Many doctors follow patients after surgery with periodic CEA tests to detect the return of colon cancer. CEA is also used to follow patients who are being treated for recurrent disease. About 3/4 of these patients will have an elevated CEA. The CEA level will decrease if treatment is effective and rise if cancer progresses. Sometimes, when the CEA is not elevated in patients with recurrent cancer, the CA 19-9 will be, and can be used to monitor the disease.

Key words: tumor markers; malignant gastrointestinal diseases; disease monitoring

 

Mario Štefanović

 

There are several classes of genes involved in carcinogenesis. For example, Tumor Suppressor Genes (TSG – e.g. p53 and the RB) when inactivated, promote carcinogenesis and protooncogenes (e.g. K-ras), when mutated promote proliferation and become oncogenes. Other classes of genes include the “housekeeping genes” or DNA repair genes.

Colorectal cancer (CRC). Mutations found in some of these tumors include genes for APC, P53, Ras or mutations in mismatch repair (MMR) genes (MSH2, MLH1, MSH6, and PMS2). Analysis of microsatellite instability (MSI) has also shown to be useful in diagnosis and as a good predictor of 5-fluorouracil mistreatment. Another marker of poor prognosis is the loss of long arm of chromosome 18. The aberrant methylation of TSGs also has been described in CRCs including P16, APC, and many others. BRAF gene mutations also have recently been found in about 10% of colorectal cancers.

Esophageal adenocarcinoma. Main interest in these tumor genetic markers is focused on loss of heterozygosity (LOH) in P53 and the RB gene, as a cause of TSG gene inactivation. P53 gene mutation has been found in 85–89% patients. P16 gene mutations are less frequent, but high prevalence of its hypermethylation, increases the risk of transformation to dysplasia or adenocarcinoma.

Pancreatic cancer. Mutations in K-ras, P53, and P16 genes, as well as in mitochondrial DNA mutations are representatives of genetic markers in this tumor type. Epigenetic representatives are aberrant gene methylation in genes like P16, cyclin D2, TSLC1, SPARC and some others. K-ras mutations have been most extensively studied, and are found in the majority of ductal adenocarcinoma, but are not specific for invasive cancer and could be found in patients with chronic pancreatitis, smokers and in patients with intraepithelial neoplastic lesions (PanINs).

Gastric cancer. This is the second most frequent cause of cancer mortality in the world, but still with no clinically useful biomarker for the early detection.

Keywords: colorectal cancer, esophageal adenocarcinoma, pancreatic cancer, gastric cancer. APC, P53, K-ras,P16

 

Nadan Rustemović^1*, Silvija Čuković-Čavka¹, Marko Brinar¹, Dunja Rogić², Boris Vucelić¹

 

Inflammatory bowel disease patients have a risk of developing pancreatitis as well as pancreatic insufficiency. Pancreatic elastase-1 is a specific pancreatic enzyme not degraded during intestinal transport and correlates with exocrine pancreatic function tests. We investigated the association of ulcerative colitis (UC) and pancreatic insufficiency as an extraintestinal manifestation of the disease. Elastase-1 levels were determined in feces of 48 UC patients and 39 healthy controls. In UC patients, disease severity was graded according to the modified Truelove and Witts criteria. UC patients underwent endoscopy and endoscopic findings were graded according to the Baron score. Levels of elastase-1 were determined using enzymimmunoassay (ELISA). Significantly lower levels of fecal elastase-1 were found in UC patients compared to controls (medians 223 vs. 1171 mg/g; P < 0.001). No significant difference in elastase levels was found between patients with and without inflammation on endoscopy criteria. Significantly lower levels of fecal elastase-1 were found in UC patients with no inflammation on endoscopy compared to healthy controls (medians 250 vs. 1171; P < 0.001). At the same time, there was no correlation between the value of fecal elastase-1 and CRP concentrations in serum.

Significantly reduced levels of fecal elastase-1 in UC patients suggest that there might be a connection between UC and pancreatic insuficiency as an extraintestinal manifestation of the diesease.