1. Conleth Feighery John Jackson Niall Conlon
Clinical immunology
Conleth Feighery
John Jackson
Niall Conlon

2. Case histories Clinical medicine - learning through a series of cases
How knowledge of immunology can help
Types of diseases
Types of tests

3. Inflammatory diseases
Specialisation -
Respiratory - asthma, lung infections
Bowel - peptic ulcer, Crohn’s disease
Brain - neurology - multiple sclerosis
Joints - rheumatology, RA, SLE
Allergy - immunology

4. Immune deficiency disorders
Primary immunodeficiency - rare, immunology
Secondary - common, e.g. HIV, infectious disease specialty

5. Making a diagnosis! Analysis of patient’s story - “the history”
The clinical findings
Which lab tests?
Which radiology tests?
Where to go from there …….

6. Patient does not wear a label !

7. In-built biases in our thinking about likely diagnosis Jerome Groopman
How doctors think
In-built biases in our thinking about likely diagnosis
Jerome Groopman

8. A case history 1 Female, 48 years Tiredness, “slowing down”
Weight gain, 5kg
Noticing the cold - cold peripheries

9. Case history 1. Questions you would ask ?
On examination - what you might look for in particular ?
Tests you might initially perform ?

10. Case history 1. Patients often use non-specific terms
Slowing down = breathlessness
Dyspnoea on exertion ?
“Systems review” - all the main body systems - respiratory, cardiac etc.
Past history ?

11. Specific terms Time to learn these and use them! Impress?? Dyspnoea
Ankle oedema
Tachycardia
Bradycardia

12. Case history 1. Examination Pale conjunctiva, palmar creases
Mild swelling of ankles - oedema
Cold hands, white fingers
Pulse 55 beats/min
DIAGNOSIS ?

13. Case history 1. Pale conjunctiva - anaemia ?
Oedema - possible cardiac failure
Cold hands - vascular disease ?
Pulse 55 beats/min - cardiac disease ??
DIAGNOSIS ?

14. Case history 1. Diagnosis - Hypothyroidism
Common disorder ~ 4% pop. affected
Need high index of suspicion
Test - thyroxine and TSH levels
Autoantibody - to “thyroid peroxidase”
Previous hyperthyroidism !
Thyroid peroxidase or thyroperoxidase (TPO) is an enzyme mainly expressed in the thyroid that liberates iodine for addition onto tyrosine residues on thyroglobulin for the production of thyroxine (T4) or triiodothyronine (T3), thyroid hormones.

15. Clinical hypothyroidism
but often the signs are not noticeable …….

16. Hypothyroidism Inflammatory damage to thyroid
Impaired synthesis of thyroid hormone
“Hashimoto’s thyroiditis”

17. Hyperthyroidism Common cause - Graves’ disease
Caused by auto-antibody to TSH receptor
Antibody can transfer across placenta - neonatal hyperthyroidism
Test - anti-TSH receptor antibody
Diagnosis - raised T4 (thyroxine) and low TSH level

18. Graves’ disease Autoantibody binds to cell receptor
Excessive thyroid hormones produced

19. Goitre

20. Graves’ disease Auto-immune thyroid disease
Typical eye findings – include the staring appearance caused by prominent eyes “exophthalmos”, eyelid retraction and “lid lag” = slow dropping down of eyelids as patient looks downwards.

21. Patient 1 has anaemia What is the cause ?
Does hypothyroidism cause anaemia ?
Chronic disease - some cause anaemia
Is it due to deficiency of haematinic ?

22. Anaemia in a 48 yr old female
Possible causes
Iron deficiency
Folic acid deficiency
Vit. B12 deficiency
Causes of deficiency ??
Haemolytic anaemia

23. Anaemia in a 48 yr old female
Iron deficiency
Blood loss ? From where ?
Dietary ?
Malabsorbtion ?

24. Anaemia in a 48 yr old female
Folic acid, B12 deficiency ?
Causes
Malabsorption !
Dietary ?
Increased folic acid requirements - pregnancy

25. Case 2 Male, 73 years Numbness, pins and needles in feet Unsteady gait
Breathless on exercise
QUESTIONS ?
Pins and needle sensation = parasthesiae
Unsteady gait = ataxia

26. Case 2 Very pale Red tongue – glossitis
Decreased sensation in lower limbs*
Unsteady gait
Otherwise appears well
* proprioception
Symptoms include numbness and/or tingling of the extremities, altered proprioception, impaired sense of smell, loss of appetite (anorexia), disturbed coordination and, if not treated in time, an ataxic gait especially in the dark when there is less visual reference[2]. In extreme cases, B12 deficiency can lead to a syndrome known as subacute combined degeneration of spinal cord.

27. B12 malabsorbtion Pernicious anaemia Auto-immune gastritis
Auto-antibodies to
Parietal cells
Intrinsic factor
Often subtle, sub-clinical presentation
Thomas Addison

28. Pernicious anaemia - auto-immune gastritis
Diagnosis –
Vitamin
B12 level

29. Pernicious anaemia Red cells enlarged = macrocytic
Atypical nuclei = megaloblastic *
Raised bilirubin – yellow pigmentation
* seen only in bone
marrow
Atypical nuclei occur in immature red cells (red cell precursors) and also in neutrophils which are said to have “hypersegmented” nuclei.

30. Text books Case studies in Immunology – Fred Rosen, Raif Geha
Essentials of Clinical Immunology – Helen Chapel, Mansel Haeney et al.
Concise Clinical Immunology for Healthcare professionals – Mary Keogan, Eleanor Wallace, Paula O’Leary

31. Case 3 Female, 33 years of age flatulence abdominal distension
Alternating diarrhoea, constipation
Given diagnosis “irritable bowel synd.”

32. Case 3
More questions ?
Examination - what features might you look for ?

33. Case 3 Hgb – 10g/dl MCV – 73 Ferritin – 8ug/L (low)
Folic acid – 3ug/L (low)
DIAGNOSIS ?

34. Iron, folic acid deficiency
Malabsorption !
Coeliac disease

35. Iron, folic acid deficiency
Malabsorption !
Coeliac disease

36. Coeliac disease
Destruction of villi - “atrophy”

37. Coeliac disease Common ~ 1% of population Subtle symptoms
Often asymptomatic
Bowel - dyspepsia, diarrhoea, bloating
Deficiency - anaemia, osteoporosis
Cause - eating gluten !

38. Gluten - essential for disease

39. Coeliac disease An auto-immune disease ?
Strong association with MHC class II allotypes - HLA-DQ2, HLA-DQ8
MHC genes ~ 40% of genetic component
Auto-antibodies - very specific !

40. Essential genetic factors

41. Endomysial auto-antibody
IgA class antibody
Highly specific - only found in coeliac disease
Very sensitive + in 85% of patients

42. Auto-antibody detection
Immunofluorescence - tissue sections with relevant antigen
patient serum aby
* subjective, specific

43. Endomysial auto-antibody
Antigen in tissue – enzyme called
tissue transglutaminase – tTG
Modifies gluten

44. Tissue transglutaminase auto-antibody - ELISA
anti-IgA
patient antibody
tissue transglutaminase
IgA class antibody
Tissue transglutaminase is the antigen found in
monkey oesophagus

45. Tissue transglutaminase auto-antibody
anti-IgA
patient antibody
tissue transglutaminase
IgA class antibody
Very specific - in 95% patient has CD
Very sensitive + in 95% of CD patients

46. Tissue transglutaminase
MOLECULAR MECHANISMS UNRAVELLED
Tissue transglutaminase
Gluten
HLA-DQ2/8
T-cells
Frits Koning, Leiden 20003

47. PQPQLPYPQP PQPELPYPQP Inflammation Greg Byrne, PhD 2006
Deamidation of gliadin peptides by tTG increases their affinity for DQ2
tTG
PQPQLPYPQP
PQPELPYPQP
Gliadin peptide
H2O
APC
DQ2
T Cell
TCR P Q E L Y
Inflammation
Greg Byrne, PhD 2006

48. Auto-immune diseases Co-associate
Thyroid disease, pernicious anaemia, coeliac disease co-exist
Also diabetes mellitus
More common in females
Auto-antibody - often diagnostic
Linked to MHC class II genes

49. Endocrine auto-immunity

50. Case history 4 23 year old female Joint pain, stiffness
Rash on sun exposed areas
Cold peripheries
Tiredness
DIAGNOSIS ?

51. Case history 4 Questions - Swelling of joints ?
Stiffness - when during day, how long ?
Rash - permanent, comes and goes ?
Cold - Raynaud’s phenomenon ?
Tiredness - sleep pattern, concentration?

52. Case history 4 Diagnosis - “Connective tissue disease”
Possibilities include -
Rheumatoid arthritis
Systemic lupus erythematosus

53. Case history 4 Investigations - Blood tests FBC Hgb 9 g/l low
WCC 3.2 x 109 /L - low
Lymphocytes x 109 /L - low
Platelets – 100 x 109 /L - low

54. Case history 4 More tests - ESR - 55mm/hr high
C-reactive protein – 5 mg/L - normal
Rheumatoid factor - negative
Anti-nuclear antibody - positive, 1280 titre

55. Anti-nuclear antibody positive staining Hep2 cells used
This homogenous pattern of diffuse bright green staining of nuclei seen by immunofluorescence microscopy with a Hep2 cell substrate is called homogenous, and is the most common pattern with autoimmune diseases overall.
Anti-nuclear antibody positive staining
Hep2 cells used
Will stain nucleus in any cell
Not specific for systemic lupus !!!

56. SLE Systemic disease - multiple areas of damage possible
Glomerulonephritis may be suspected by presence of red cell casts in urine.
Systemic disease - multiple areas of damage possible
Red, white cells and platelets often affected

57. Case history 4 Diagnosis
Findings suggestive of systemic lupus erythematosus
Additional tests ?
Antibody to double stranded DNA ?

58. Anti-dsDNA Crithidia lucilea
Specific finding in systemic lupus erythematosus
Crithidia lucilea

59. ds DNA antibodies

60. SLE - synovial inflammation

61. SLE synovial inflammation

62. “butterfly” rash on “malar’” region of face photo-sensitive
This malar (or butterfly) rash over the face of a young girl is a typical rash seen with SLE. The rashes are made worse by UV rays, sunshine
“butterfly” rash on “malar’” region of face
photo-sensitive

64. SLE - classic butterfly rash

65. Rheumatoid arthritis Commonest form of connective tissue disease
No diagnostic blood test !!

66. Rheumatoid arthritis
Joint deformity in established disease

67. Rheumatoid arthritis X-ray findings very helpful in diagnosis
Lytic lesions on X-ray

68. Rheumatoid arthritis

69. Rheumatoid arthritis

70. Rheumatoid arthritis Common - 1-2% of population Female > male
Older age group - 50s +
Chronic, destructive arthritis in some pts
Reduced life expectancy
Anti-TNF drugs beneficial

71. Rheumatoid arthritis Rheumatoid factor positive = “RF”
RF = IgM antibody to IgG
NOT specific for RA
New antibody test – antibody to “cyclic citrullinated peptide” – more specific for RA
anti-cyclic citrullinated peptide (anti-CCP)

72. Other connective tissue diseases
Some have features similar to lupus
Commonly ANA positive but ……
Also have antibodies to other specific antigens
These are antibodies to so-called “extractable nuclear antigens” = ENA

73. Sjogren’s syndrome Dry eyes, dry mouth
Inflammation in salivary, lacrimal glands
ENA antibodies – anti-Ro, anti-La*
Ro and La named after patients

74. Scleroderma Condition in which skin thickening develops
Caused by deposition of collagen in skin and internal organs
ENA antibody – anti-Scl-70

75. Tightening of skin in some types of CTD
“Scleroderma”

76. End of lecture 1