Crohn's disease: diagnosis

Laboratory and instrumental data

1. General blood test: anemia, leukocytosis, increased ESR. These changes are most pronounced in the active phase of the disease.
2. General urine analysis: without significant changes. In the active phase, there may be the appearance of proteinuria, microhematuria.
3. Biochemical analysis of blood: a decrease in albumin, iron, an increase in 02 and gamma globulins, alanine aminotransferase, and sometimes bilirubin.
4. Immunological analysis of blood: increasing the number of immunoglobulins, circulating immune complexes, reducing the number of T-lymphocytes - suppressors.
5. Coprologic analysis: macroscopic impurity of blood and mucus is detected, in the absence of clearly visible blood, an increased amount of erythrocytes, always a positive reaction to latent blood (the Gregersen River) and a soluble protein (the Tribula River), many epithelial cells and leukocytes.
6. PHAGS: allows to reveal the defeat of the upper parts of the gastrointestinal tract. The defeat of the esophagus is extremely rare, manifested by a picture of the inflammation of the mucosa of the esophagus, sometimes by ulceration. The diagnosis is refined with the help of a histological examination of biopsies of the esophagus mucosa. Stomach lesion is observed only in 5-6.5% of patients, the most characteristic is the isolated lesion of the antral part of the stomach or the combination of the lesion of the stomach and the initial part of the duodenum. However, it may not be the initial lesion of the stomach, but its involvement in the pathological process with far-gone intestinal lesions (terminal stage of the disease). The defeat of the stomach manifests itself as an infiltrative inflammatory process with ulceration in the center. The diagnosis is refined with the help of a histological examination of the biopsy specimens of the gastric mucosa.
7. Endoscopic examination of the intestine (sigmoidoscopy, colonoscopy). Rectoromanoscopy is informative in those cases when the rectum involves the rectum (in 20% of patients). The most important is fibrocolonoscopy with a biopsy of the intestinal mucosa. The endoscopic picture depends on the period and activity of the process.

In the initial stage of the disease, against the background of a dull (not shiny) mucous membrane, erosion-aphthae, surrounded by whitish granulations, are visible. On the walls of the intestine in the lumen there are mucus and pus. As the disease progresses and the activity of the process increases, the mucosa thickens unevenly, acquires a whitish appearance, large ulcers (superficial or deep) appear, more often longitudinally located, there is a narrowing of the gut lumen (cobblestone bridge pattern). During the period of greatest activity, the inflammatory process spreads to all layers of the intestinal wall, including the serous membrane, and fistula is formed.

In the future, cicatricial narrowing is formed on the site of ulcer-cracks.

8. Microscopic examination of biopsy specimens of the mucosa: a biopsy should be carried out so that the biopsy site has a portion of the submucosal layer, because in Crohn's disease the process begins exactly in it and then spreads transmurally. Microscopically revealed the following features of the pathological process:
   • the submucosa is most affected, to a lesser degree - the mucous membrane;
   • Inflammatory-cellular infiltrate is represented by lymphocytes, plasma cells, histiocytes, eosinophils, against which sarcoid granulomas with giant Langer cells are determined.
9. X-ray examination of the intestine: Irrigoscopy is performed in the absence of rectal bleeding. Characteristic features of Crohn's disease are:
   • segmentation of bowel disease;
   • presence of normal areas of the intestine between the affected segments;
   • uneven bowel contour;
   • longitudinal ulcers and mucosal relief, reminiscent of "cobblestone pavement";
   • narrowing of affected areas of the intestine in the form of a "cord";

X-ray examination of the small intestine is most expedient to carry out with the introduction of barium through the probe for a bunch of Treits (P.Ya. Grigoriev, AV Yakovenko, 1998). X-ray signs of a small intestine lesion are the same as that of the large intestine.

10. Laparoscopy: performed primarily for the purpose of differential diagnosis. The affected parts of the intestine, especially the terminal ileum, look hyperemic, refined, edematous; There is also a thickening and an increase in the mesenteric lymph nodes.

Differential diagnosis of Crohn's disease

Crohn's disease has to be differentiated with almost all the diseases that occur with abdominal pain, diarrhea with blood and weight loss, and amoebiasis. Dysentery, pseudomembranous and ischemic colitis, tuberculosis and intestinal cancer.

The form of Crohn's disease with a predominant lesion of the terminal segment of the ileum requires differential diagnosis with iersiniosis. In this case, the most important diagnostic test is the dynamics of titers of specific anti-ceresinous antibodies, diagnostic titers of not less than 1: 160 are considered diagnostic (antibodies are usually detected in serum on days 7-14).

[1], [2], [3], [4], [5], [6], [7], [8], [9]