Clinical Immunology Conleth Feighery John Jackson

Auto-antibodies Often very helpful in making diagnosis Rarely entirely specific – i.e. can occur in range of diseases ANA, rheumatoid factor examples of this

Auto-antibodies ANA usually positive in connective tissue diseases - CTD Sub-categories of ANA may define the type of CTD Double stranded DNA – exclusive to SLE Antibodies to “extractable nuclear antigens” define other types of CTD

Case 6 32 year old bank official Dry mouth +++ Water to bedside Customer interaction difficult Fatigue +

Case 6 Examination - Reduced saliva Sub-mandibular gland swollen Dental damage

Extractable nuclear antigens Antibodies to sub-fractions of nucleus Ro antibodies – found in a ‘common’ CTD called Sjogren’s syndrome – in ~ 75% of pts Also found in other CTDs including lupus – so not specific

Sjogren’s syndrome Features Inflammation of glands - lacrimal, salivary Symptoms - dry eyes, dry mouth Joint, muscle symptoms - sometimes Associated CTD - RA, SLE …. Older females

Case 6 - Sjogren’s syndrome Confirming the diagnosis - History Quantify tears, saliva production Biopsy ? Autoantibodies – ANA positive – Ro antibody positive

Case 6 - Sjogren’s syndrome Cause - Lymphocytic infiltrate of exocrine glands Salivary, lacrimal, genital glands affected Monoclonal expansion of B cells can occur Lymphoma may develop

Case 6 - Sjogren’s syndrome Associates with other diseases SLE Rheumatoid arthritis Thyroid disease Primary biliary cirrhosis HLA genes associated

Ro antibodies Can cross placenta and rarely - Cause complete congenital heart block – Damage to heart conducting system Cause skin inflammation – ‘neonatal lupus’

ENA antibodies - valuable Help define type of CTD - Sjogren’s syndrome - Ro, La antibodies SLE - Sm antibodies Scleroderma - Scl 70 antibodies Anti-RNP - mixed connective tissue disease

Case 7 44 year old female Arthralgia, myalgia Raynaud’s phenomenon Fatigue

Case 7 Examination - Mild sclerodactyly Telangiectasia, hands, face

Sclerodactyly of fingers Sclero = hard Dactyly = digit

Telangiectasia

Case 7 diagnosis is CREST Clinical findings Centromere auto-antibody C = calcinosis R = Raynaud’s E = oesophagus S = sclerodactyly T= telangiectasia

Anti-centromere antibody - ANA observed in dividing cells Positive in 70% of CREST patients

Systemic sclerosis (scleroderma) More severe version of CREST Skin thickening – arms, thorax, face GIT structures affected – oesophagus – dysphagia - small intestine – dysmotility, malabsorption Lungs – fibrosis Caused by deposition of collagen - unexplained

Systemic sclerosis (scleroderma) Auto-antibody – to a ENA Anti-Scl 70 - antigen is enzyme topoisomerase I

Case 8 Female, 54 years Fatigue Skin itch x 2 years Mild icterus Examination Generally healthy Icterus confirmed Liver, spleen size normal

Liver auto-immunity Primary biliary cirrhosis Females Middle-aged Inflammatory process focused on intra-hepatic biliary tree Liver failure – common reason for liver transplantion

Case 8 auto-antibody tests 2 helpful auto-antibodies – Anti-mitochondrial antibody Confirmatory antibody to enzyme - Anti-pyruvate dehydrogenase (PDH)

Mitochrondrial antibody Kidney tubule tissue

Primary biliary cirrhosis Liver granuloma – early disease Established cirrhosis

Chronic active hepatitis Females Often in younger age group – 20s Less common form of liver disease Antibodies to “smooth muscle” BUT not specific for this disease

Connective tissue disease Vasculitis

Inflammation - focus on blood vessels Damage to blood vessel - – local thrombosis, – haemorrhage – damage to tissue it supplies

Vasculitic lesions in vasculitis

WG – case No other systemic symptoms Decision to treat with cyclophosphamide, steroids

Blood vessel size in vasculitis

Vasculitis Clinical presentation can be obscure Systemic inflammatory disease - ? cause Pyrexia of unknown origin Infection ?? Malignancy ??

Wegener’s granulomatosis Small vessel vasculitis Classically affects - Upper respiratory tract – nose, ears, sinuses Lower respiratory tract - lungs Kidneys But can affect any organ, including skin GIT sometimes, but less common

Wegener’s granulomatosis Bleeding is often the clue! Nasal – epistaxis Lungs – haemoptysis Kidney – haematuria PUO – pyrexia of unknown origin Systemic symptoms – joint, muscle pain

Wegener’s - clinical features Episcleritis Saddle nose deformity

Wegener’s granulomatosis Diagnosis often missed in past Not uncommon disorder – but many medics have not seen a case 100+ cases diagnosed in 15 years, SJH Clinical features can be atypical Auto-antibody – specific, sensitive – use leading to increased diagnosis

WG – case, 1992 RE - 26 year old Australian, on world tour 3 week history of haemoptysis Possible weight loss of 6kg Arthralgia - large joints Rash - macular, erythematous

WG – case Rapid deterioration - in 1 week Temp 38 Synovitis of small joints Episcleritis Blistering necrotic skin rash Haemoptysis +++

WG - case 1 Differential diagnosis - Tuberculosis ? Carcinoma of lung ? Bacterial infection ? Auto-immune disease – vasculitis ?

WG - case 1 WCC - 25 x 10 9/ L Urine - haematuria, proteinuria Lung biopsy - alveolitis (ICU) Auto-antibody screen + C-ANCA DIAGNOSIS - Wegener’s

C-ANCA PR3+

Wegener’s auto-antibodies First step - Anti-neutrophil cytoplasmic antibody = ANCA Immunofluorescence test Second step - Anti-PR3 ELISA

Wegener’s granulomatosis Why is the diagnosis missed ? Limited Wegener’s – upper airways alone – Sinusitis – Rhinitis – Deafness Skin or other organ alone Diagnosis not considered

Wegener’s granulomatosis Treatment Immunosuppressive drugs – cyclophosphamide Steroids Good response usually – mortality of disease reduced +++

Wegener’s granulomatosis However - Relapse is very common ~ 50% Further organs may become involved Chronic renal damage may develop – dialysis, transplant

Another case …… Another example of connective tissue disease Auto-antibodies help “dissect” the condition

Case year old female parachutist Presented with marked ecchymosis - sites of parachute strap marks Mild arthralgia, fatigue DVT in calf 1 year previously

Case 8. Tests - v.low platelet count 7 x 10 9 WCC count 3 x 10 9 Haemoglobin 10g ANA positive, titre 640 Diagnosis ??

Case 8. Further auto-antibody tests – Anti-cardiolipin antibody ++ – Anti-beta2-glycoprotein antibody ++ Diagnosis ?? Anti-phospholipid syndrome

Classic features Thrombosis - recurrent Thrombocytopaenia Miscarriages - recurrent

Anti-phospholipid syndrome Associated with connective tissue disease - especially SLE Overlaps with ITP - idiopathic thrombocytopenic purpura May have clinical features like - TTP - thrombotic thrombocytopenic purpura ??

Case Remained well for 10 years Developed mild arthritis dsDNA antibody positive

Case 8 - January 2006 Dyspnoea on exertion Anaemia, low WCC, low platelets Hypertension Marked lower limb oedema

Case Casts - red cells in urine Marked proteinuria - nephrotic Renal biopsy - diffuse proliferative glomerulonephritis (class IV) Diagnosis - SLE

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