Inflammatory disorders Flashcards
(56 cards)
How can ischaemia cause mucosal injury in the gut
- Systemic hypotension- affects intestinal mucosa
- Atherosclerotic disease
- Volvulus- colon twists on part of mesolcolon, obstructs veins
What drugs can cause mucosal injury of gut
NSAIDs,(Ibuprofen and diclofenac can cause ulceration, peptic ulcers) antibiotics, steroids
Chemotherapy e.g. 5-fluorouracil ⇒ Affects stem cells at bottom of pits
What classificiation system is used for gastritis and how is it classified
The Sydney System uses a combination of endoscopic features, histology and aetiology to classify gastritis
Main types of gastritis and their causes
Acute erosive / haemorrhagic gastritis ⇒ Ingestion of irritant chemicals causes damage to the surface of mucosa
Acute H. pylori infection usually no or minor symptoms, so seldom seen in biopsies
Chronic:
non atrophic like Hp
atrophic like autoimmune or chronic hp also
Special forms
What are the obvious hallmarks of non-atrophic gastritis ( chronic and active)
chronic -Lymphocytes and plasma cells in lamina propria
Active- neutrophils infiltrating epithelium of gastric pits
What is atrophic gastritis characterised by and what are the causes
characterised by loss of parietal (acid secreting) and peptic (pepsin secreting) cells in gastric body ( usually occurs in mucosa)
- Autoimmune gastritis ⇒ Need serology for anti parietal cell antibodies which affect fundus.
- Chronic H. pylori infection
Causes of Non-infectious granulomatous gastritis
e.g. Crohn’s disease, sarcoidosis
What is coeliac disease histology characterized by
- Chronic mucosal inflammation
- Variable Villous atrophy ⇒ flat surface
- Crypt hyperplasia ( as compensation) ⇒ longer crypts
May also have Increased CD8+ T- Lymphocytes in epithelium ⇒ Epithelial damage ⇒ Leads to malabsorption
Increase in lamina propria lymphocytes and plasma cells as well
Waht is coeliac disease diagnosed by
- Histology ( biopsy changes)
- Serology
- Response to gluten - free diet
How is coeliacs often picked up
routine haematology (iron deficiency anaemia) => presents as tiredness
What genes predispose for coeliac’s
HLA DQ2, DQ8
Pathophysiology of coeliacs
- Exposure to gluten (gliaden) in wheat, barley, rye or other glutamine- rich proteins (hordeins and secalins) results in:
- Gliaden-reactive T lymphocytes
- Tissue transglutaminase antibodies
What may be the presenting complain in some coeliac patients
Dermatitis herpetiformis ⇒ Blistering skin condition, CAN be presenting complain in some coeliac patients!!
Common presentations of coeliac
- Diarrhoea
- Abd pain, bloating, general sense of unease in stomach
- Anaemia ⇒ From iron or folate deficiency
- Dyspepsia
- Weight loss
- Recirring mouth ulcers may be common
- Fatigue
- Neuropsychiatric symptoms
Classical presentation of coeliacs
- Childhood
- FTT / Weight loss
- Short stature
- Malnutrition
- Steatorrhoea
- Delayed puberty
- Osteomalacia
- Myopathy
Investigations of coeliacs
what deficiencies are more common
- Anaemia (microcytic, macrocytic)
- Iron, folate deficiency
- Macrocytosis without anaemia
- Hyposplenic blood film due to splenic atrophy
- Low calcium, elevated Alk Phos due to met. bone disease
- Raised transaminases ⇒ liver enzymes, reasons not clear
- Hypoalbuminaemia
Testing for coeliacs
- Serological markers
- Anti-tissue transglutaminase antibody (IgA) (TTG) Sensitivity and specificity >95% ⇒ Usually can be used simply for diagnosis now in paeds w/o biopsy
- Anti-endomysial antibody (IgA)
- Anti-gliadin antibody (IgA, IgG)
- Anti-tissue transglutaminase antibody (IgA) (TTG) Sensitivity and specificity >95% ⇒ Usually can be used simply for diagnosis now in paeds w/o biopsy
- Small intestinal biopsy ⇒ Definitive test- show pathological features
- Scalloping, Loss of Kerking’s folds, mosaic pattern
What infection is common after broad spectrum antibiotics
C diff
What infection is more common in immune suppressed individuals, and what is the common histology
CMV -treatment of ulcerative in crohns
- Intranuclear and cytoplasmic inclusions are typical ⇒ accumulation of viral proteins in cytoplasm and nucleus
Intranuclear and cytoplasmic inclusions are typical ⇒ accumulation of viral proteins in cytoplasm and nucleus
In which part of the intestine is giardia infection more common
duodenum
where does ischaemic colitis often occur in
Mimics Crohn’s, most common in region of splenic flexure and descending colon
What is divericular disease and which group is it most common in . What is a complication
- In elderly, has chronic complications ⇒ stricture and fistulas
- Most common in sigmoid colon
Ulceration may eventually result in fistula
What drug is more likely to cause colitis and where does it affect most often
NSAIDs, TI
How does distribution of UC and CD differ
UC - inflammation is confined to mucosa, diffuse in distribution, while Crohn’s has skip lesions and is transmural
