Applied Pathophysiology: Inflammation and Repair

Applied Pathophysiology- Inflammation and Tissue Repair

• This lecture series covers Applied Pathophysiology: A Conceptual Approach to the Mechanisms of Disease, focusing on inflammation and tissue repair (Chapter 3), and clinical models (Module 4).
• The material is adapted from 2017 Wolters Kluwer Health publications, Lippincott Williams & Wilkins.
• The lecture series is part of the MPAT12001 Medical Pathophysiology Lecture Series, taught by Dr. Romeo Batacan Jr.

Inflammatory Bowel Diseases (IBD)

• IBDs are chronic, relapsing inflammatory disorders of the bowel, of unknown origin (idiopathic).
• Genetic factors, autoimmune responses to intestinal flora, abnormal T-cell responses, and altered epithelial barrier functions are potential contributing factors.
• IBD is most common in the small and large intestine, It can affect any part of the GI tract.
• Crohn's disease and ulcerative colitis are the most common forms of IBD.

Crohn's Disease Pathophysiology

• Crohn's disease is a chronic granulomatous inflammatory disorder.
• Family history, environmental factors (smoking, diet, microorganisms), are potential risk factors.
• It can affect any part of the digestive tract, from mouth to anus.
• The small intestine is the most common site.
• It is a recurrent condition.
• Non-continuous penetrating ulcerations and fibrosis (skip lesions) are key features.
• Ulcers can produce longitudinal and transverse inflammatory fissures that extend into the lymphatics.
• Inflammation typically begins in the mucosa and submucosa, leading to increased permeability and vascular changes (edema and fibrosis).
• Cellular response develops, granulomas form.
• Bowel segments can become further inflamed, and interior surfaces thicken due to edema, fibrosis, and granulomas.
• Ingested food can be obstructed, leading to ulcers and fistulas (abnormal passages between bowel segments).
• Abscesses (pus pockets) and adhesions (scar tissue) can form, limiting bowel function.
• Australia has approximately 28,000 cases.

Crohn's Disease Clinical Manifestations

• Symptoms often depend on the location of the affected area and include rapid stool transit times, intestinal edema, fibrosis, loss of absorptive function, abdominal pain, diarrhea, malnutrition, occult blood in stool, bowel obstruction, fever, weight loss, and fatigue.
• Anemia may result from vitamin B12 and folic acid malabsorption.

Crohn's Disease Diagnostic Criteria

• Diagnosis involves an assessment of the patient's history and physical examination for differentiating if similar to ulcerative colitis.
• Endoscopic examination to assess mucosal involvement.
• Imaging (X-ray or CT scan) can identify abscesses, fistulas, or obstructions.
• Stool cultures to rule out infection.

Crohn's Disease Treatment

• Treatment is symptomatic, aiming to manage symptoms.
• Pharmacologic treatment suppresses inflammation and the immune response.
• Dietary changes are important, avoiding foods that can irritate the bowel, and ensuring sufficient calorie & protein intake during exacerbations, while limiting fat and fiber.
• Surgical removal of damaged bowel or repairing fistulas can be considered.
• Patients with Crohn's disease have a higher risk of small intestine and colorectal cancer.

Ulcerative Colitis Pathophysiology

• Ulcerative colitis is a chronic inflammatory disease confined to the colon and rectum.
• The inflammation begins in the rectum and ascends the descending colon.
• The affected areas are continuous and superficial.
• Mucosal inflammation is characterized by friability, leading to bleeding.
• Repeated cycles of ulceration alternate with the deposition of granulation tissue during the healing phase.
• Symptoms of hemorrhagic lesions, abscesses, and necrotic tissue, ulceration, and raised inflammatory tissue (pseudopolyps) can occur.
• Perforation, obstruction, and massive hemorrhage are possible consequences.

Ulcerative Colitis Clinical Manifestations

• Symptoms relate to large intestine irritability (friability) and inflammation.
• Common symptoms include diarrhea, rectal bleeding, and abdominal pain.
• Systemic symptoms include fever, weight loss, fatigue, and anemia (due to poor absorption).

Ulcerative Colitis Diagnosis

• Diagnosis relies on a combination of history, physical examination, endoscopic evaluation, checking for mucosal inflammation, and imaging (radiography/CT) to assess for abscesses, fistulas or obstructions.
• Stool cultures rule out infection.
• Determining frequency, and presence of blood (severity) in the stools are diagnostic factors.

Ulcerative Colitis Treatment

• Treatment aims to manage symptoms (symptomatic).
• Pharmacologic agents are used to suppress inflammation and immune response.
• Dietary modifications are necessary, such as avoiding milk, caffeine, and spicy foods.
• Adequate fluid intake is crucial.
• If perforation or obstruction occurs, surgical interventions are necessary.
• The risk of colon cancer is higher than in Crohn's disease.

Comparison of Crohn's Disease and Ulcerative Colitis

• A table summarizing key differences between Crohn's disease and ulcerative colitis: location, pattern of lesions, diarrhea characteristics, abdominal pain, bowel obstruction, and cancer risk.

This quiz covers the concepts of inflammation and tissue repair as outlined in Chapter 3 of Applied Pathophysiology. It delves into inflammatory bowel diseases, focusing on their pathophysiology, including Crohn's disease and ulcerative colitis. Prepare to test your knowledge on the mechanisms of disease related to these conditions.