Auto-immunity cases

1. Auto-immunity cases Con Feighery

2. Auto-immunity • Immune mediated damage • Absence of infection or other cause • Auto-antibodies may be present • Detection of auto-antibodies – help in diagnosis • Auto-antibodies often NOT cause of damage

3. Auto-immunity Characteristic features - • Female preponderance • Auto-antibodies – some are pathogenic • Genetic association – often strongly associated with MHC class II genes

4. Case 1 – 35 year old female • Joint pain, swelling for 6 months, intermittent • Hands and wrists most affected • Sharp pain in chest on breathing, intermittent • No energy x 2 years • Otherwise generally well

5. Case 1 – 35 year old female • Examination – • Generally healthy • Some swelling, tenderness of hand, wrist joints • Pulse rate 90 beats per min • Heart and chest exam normal • Skin rash on face

6. Case 1 – 35 year old female

7. Case 3 – 35 year old female • Test results • Haemoglobin 10g/dl – low • White cell count 3.4 – low • Platelets – 100 – low • Chest x-ray – normal • Rheumatoid factor test (antibody to IgG) - positive

8. Case 3 – 35 year old female • Questions • What do you think is ‘going on’ in this patient? • Do you think she might have arthritis? • What is the cause of her chest pain? • What might be the cause of her lack of energy?

9. Case 3 – 35 year old female • Questions • Do you have any further ideas about what might be the wrong with this patient? • What additional tests might help decide?

10. Case 1 – 35 year old female Answers • Possible diagnoses include “lupus” aka SLE or rheumatoid arthritis • Autoantibody tests will help • Anti-nuclear antibodies found in SLE • Double stranded DNA antibodies only in SLE • Rheumatoid factor (antibody to IgG) is found in rheumatoid arthritis, other diseases

11. Antinuclear antibody test

12. Antibody to double stranded DNA Crithidia luciliae – kinetoblast contains dsDNA

13. Case 3 – 35 year old female Answers – common features in lupus (SLE) include - • Low white cell and platelet counts • Skin rash on face “photosensitive” a classic feature • Chest pain – lung lining inflammation occurs – “pleurisy” • Energy – due to anaemia, other causes?

14. Multiple ‘systems’ affected by lupus

15. SLE • Classic example of “multi-system” auto-immune disease • Only 1 or 2 systems involved in many patients • Female:male ratio 9:1 • ANA positive – 99%

16. Case 2 - 14 year old male Case history • JG, 14 year old male • Intermittent diarrhoea x 3 years • Occasional abdominal pain • Mild abdominal distension • Fatigue, arthralgia

18. Clinical history (continued) • Past history – well until 11 years old • Family history – mother has rheumatoid arthritis; aunt is hypothyroid

19. Physical examination Examination – • Thin; weight – 6 stone (38 kg); height – 4 feet, 10 inches (147 cm) • Pre-pubertal • Pale facies; pulse 90/min, regular; chest clear • Abdomen – mild distension, slight tenderness • Joints – no synovitis; skin – no rashes

20. Early blood test results • Hgb – 9g/dl; MCV – 75fl • WCC – 11 x 109/l; platelets 500 x 109/l • ESR – 45mm/hr; CRP 80 mg/l – both raised • Albumin 28g/l; GGT 93 IU/l; Alk phos. – 140 IU/l • Urea, creatinine, electrolytes normal

21. Further blood test results • Complement levels – C3 – 80 g/l; (normal); C4 – 16 g/l (normal 0.16 – 0.70) • Immunoglobulins – IgG – 18g/l; IgM – 2g/l; IgA < 0.05 g/l • ANA +, titre 320; Smooth muscle antibody +, titre 80 • ANCA +, perinuclear pattern, titre 80 • Gliadin antibodies +, 30 units (normal range < 5 units)

22. Discussion issues • What additional information would you like to have about the patient’s history?

23. Discussion issues • What further physical findings would you look for?

24. Discussion issues • What further diagnostic tests should be considered?

25. Discussion issues • How would you interpret the above findings? • What would you include in the differential diagnosis? • What early investigations are warranted? • What specific tests would you perform?

26. Case 2 – further tests • If this is coeliac disease, test for endomysial antibodies – c. 100% specificity • Or perform biopsy of small intestine

27. Endomysial antibody test > 99% specific for coeliac disease

28. Coeliac disease

29. If this is inflammatory bowel disease? • Examine bowel via endoscope • Small bowel biopsy • Image the bowel via X-ray with barium

30. Crohn’s - endoscopy Normal small bowel Crohn’s small bowel with linear ulcers

31. Crohn’s histology Classic granulomatous inflammation

32. Small bowel barium studies Crohn’s disease - stricture of terminal ileum Coeliac disease “coin stacking”

33. Inflammatory bowel disease Ulcerative colitis Crohn’s disease

34. Capsule endoscopy – Crohn’s

35. Outcome in patient JG 1. • This patient was incorrectly diagnosed with coeliac disease, on the basis of raised gliadin antibodies, a non-specific test for coeliac disease • He failed to improve on a gluten free diet

36. Outcome in patient JG 2. • A barium follow through examination showed narrowing of the terminal ileum • This was resected and Crohn’s pathology confirmed • He has had several further resections and now has a short bowel syndrome

37. Crohn’s disease • Immune mediated disease • No female preponderance • No specific auto-antibodies • 12 gene loci – GWAS* • No very strong MHC association * Genome wide association study

38. Case 3 – 38 year old female • Just delivered baby boy • Little weight gain during pregnancy • Told she had ‘anxiety’ • Nervous tremor • Family history – sister with coeliac disease

39. Case 3 – 38 year old female • Baby healthy but very fast heart rate - 160 beats per min. • Mum also has fast heart rate – 100 beats per min. and irregular beats • Brisk reflexes • Staring eye appearance

40. Case 3 – 38 year old female

41. Prominent, bulging eyes

42. Case 3 – 38 year old female • What diagnosis might you consider? • What tests would you do?

43. Case 3 – 38 year old female • Patient has hyper-thyroidism • Caused by antibody vs. TSH receptor Diagnosis • Measure TSH antibody • Measure thyroid hormone levels

44. Case 3 – 38 year old female • Cause of rapid heart rate in baby? • Relevance of sister with coeliac disease?

45. Case 3 – 38 year old female • Cause of rapid heart rate in baby? Answer • IgG antibody crosses placenta and reacts with baby’s TSH receptor • Neonatal hyperthyroidism - temporary

46. Case 3 – 38 year old female • Relevance of sister with coeliac disease? • Co-association of autoimmune diseases • Note – many Graves’ disease patients develop hypothyroidism over time • Hypothyroid patients – develop antibodies to thyroid peroxidase – marker of thyroid inflam

47. Endocrine auto-immunity

48. Case 6 – 80 year old female • Known hypothyroidism • Loss of energy, dysponea on exertion • GP – pale, yellowish pigment • Hg 4g/dl; MCV 115fl • B12 level – very reduced

49. Case 6 – 80 year old female • Diagnosis – B12 deficiency • Pernicious anaemia • Auto-immune gastritis • Parietal cell auto-antibodies • Intrinsic factor antibodies**

50. Case 4 – 25 year old male • Easy bruising on thighs • Bleeding following shaving • Attended GP – Hgb 10g/dl, iron deficient • Coagulation tests performed – normal • What other information would you request?