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Crohn's Disease

Inflammatory disabling sickness of the alimentary canal carries the name of American gastroenterologist Burrill Bernard Crohn, who was the first to describe the disease in 1932. Bernard Crohn in collaboration with his fellow physicians published a thorough description of an unknown in those times intestinal disorder, called terminal ileitis initially. However, their paper was published as “Regional Ileitis, A Pathologic and Clinical Entity”. The mastery original delineation of fourteen cases remarkably still remains the basis for clinical diagnostics.

In Crohn’s disease inflammatory bowel disease is thought to result from inappropriate and ongoing activation of the mucosal immune system, its overreacting driven by the presence of normal luminal flora (Podolsky, 2002). However, genetic factors are reported to play a major role in its pathogenesis. For example, gene within the 16th chromosome which regulates macrophage apoptosis, and a group of genes on the 5th chromosome that encode cytokines receptors have been linked to the malady. Nevertheless, Podolsky (2002) reports only 45 percent of pairs of identical twins are concordant for the disease. Thus, environmental causes are believed to be the crucial factors in the onset of Crohn’s disease. The most important of them are non-steroid anti-inflammatory drugs, smoking, luminal flora, diet and maybe psychological factors.

Crohn’s disease is much more common in developed countries, rather than other areas, the fact that had not been explained yet. Sands (2006) points to ethnical patterns of the disorder: American Jews of Eastern European descent are 4-5 more times likely to develop Crohn’s disease while Asians and Hispanics present the lowest prevalence. Caucasians have the highest risk to develop the disorder. Crohn’s disease may affect individuals at any age, but usually strikes males and females equally aged between 15 and 35 years.

Crohn and colleagues (1932) describe a chronic disorder of young adults presenting with fever, diarrhea, and right lower quadrant abdominal pain, accompanied with anemia and fatigue. Symptoms of the disease may range from mild to severe and include diarrhea, pains, rectal bleeding, cramping. Fever, abdominal masses and growth retardations in the young are common. Either colon or proximal levels of the gastrointestinal tube (esophagus, duodenum, jejunum, ileum) may be affected. When severe cases of Crohn's disease occur, other signs and symptoms can include arthritis, inflammation of a bile duct or the liver and skin rashes.

Since 1976, Crohn's Disease Activity Index has been in use to quantify the symptoms of the disease. This tool consists of eight contributing factors, namely number of liquid or soft stools each day for seven days, abdominal pain, general well being, presence of complications, taking Lomotil or opiates for diarrhea, presence of an abdominal mass, low hematocrit and percentage deviation from standard weight. A simpler to use in clinical realities is Harvey-Bradshaw index, which includes general well-being, abdominal pain, number of liquid stools per day, abdominal mass and complications.

Endoscopic findings are of paramount importance for diagnostics of Crohn’s disease: aphthous and linear ulcers and cobblestone appearance of the lumen are considered pathognomonic for this diagnosis. Anti - Saccharomyces cerevisiae antibodies are found in more than 50% of diseased individuals. In recent years, many studies have been introduced into practice to diagnose Crohn’s disease. Because the disorder often affects young, frequent reevaluation may be necessary, stimulating new imaging techniques to be carried out:

 

  1. conventional enteroclysis – barium mixed with methylcellulose solution injected through a nasoenteric tube with subsequent X-ray imaging
  2. ultrasonography – a painless non-invasive cheap tool which allows to visualize wall thickening the intestines, evaluate its stratification and motility, conglomeration and increased lymph nodes
  3. color and power Doppler ultrasonography – measures arterial and venous flows in the mesenteric vessels, and determines alterations in the vascular nature of inflammation
  4. contrast-enhanced ultrasonography – micro bubbles resonating with ultrasound, enhanced images are obtained that allows accurate appreciation of parietal vascularization
  5. multidetector CT enteroclysis - a highly precise method to reveal mural and extraluminal lesions and abscesses (to compare with conventional enteroclysis, which is more appropriate for luminal abnormalities)
  6. MRI enteroclysis – a non-radiation tool to evaluate disease activity and obtain intra- and extraintestinal lesions
  7. Tc-Labeled leukocyte scintigraphy – identifies the exact topography of inflammation and quantifies its activeness.

 

Capsule endoscopy is a novel approach to video imaging of the gastrointestinal mucus.

Crohn’s disease is not actually a lethal disease. However, if left untreated, the sickness leads to profound disabilities or even death (Ferrara, 2010). The long-term management of inflammatory bowel disease must be multidimensional and governed by the type of disease and sites involved. Historically, corticosteroids were the mainstay to treat inflammation in Crohn’s disease, followed by 5-aminosalicylic acid compounds and cytostatics. Clinical evidence notes that corticosteroids do not modify the disease itself, though may induce remission in nearly a half of cases. Anti-inflammatory properties of aminosalicylates are commonly used in spite of poor data for value to their effectiveness. Antibiotics are the first line to treat complications of Crohn’s disease, but Sands (2006) reports metronidazole is believed by some to be an alternative to corticosteroids. Immunomodulating remedies show slow onset of action, so they are drugs for long-term treatment regimen. However, these are cytostatics that show the effectiveness in supporting remission. Recent scientific finding indicate tumor necrosis factor alfa (TNF-a) antagonists might actually regulate inflammation itself, and even promote complete healing of the mucosa.