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A beginners guide to SLE. Dr Mike Martin St James’s Univ. Hosp. Systemic Lupus Erythematosus. 1. Autoimmune, inflammatory, multisystem disease 2. Associated with pathogenic autoantibodies resulting in immune complex formation and complement mediated tissue damage
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A beginners guide to SLE Dr Mike Martin St James’s Univ. Hosp.
Systemic Lupus Erythematosus 1. Autoimmune, inflammatory, multisystem disease 2. Associated with pathogenic autoantibodies resulting in immune complex formation and complement mediated tissue damage 3. Characterised by remissions & relapses 4. Variable course and prognosis
Auto-immune disease • Antibody producing cells (lymphocytes and plasma cells) are presented with antigen. • The antigen-antibody complex will be coated in compliment (C3 + C4) – opsonisation. • These circulating complexes are normally removed by the reticulo-endothelial system. • In auto-immune disease these complexes locate to certain tissues and cause damage and disease.
Factors contributing to autoimmune disease eg SLE • Genetic • Hormonal • Environmental • Stress
SLE is more common in • women • Afro-Caribbean and Asians Irrespective of • country of birth • social class • place of residence Johnson et al. Arthritis Rheum. 1995. 38: 551-558
Epidemiology • Prevalence • total: 28/100,000 • female 50/100,000 = 1/2000 • In women: Afro-Carib1/500; Asian 1/1,000; Caucasian 1/2,500 • Incidence: total 4/100,000 • female 7/100,000
Immunology • The ready detection of numerous antibodies to cellular components of the nucleus, cytoplasm and cell membrane has led to the concept that lupus is an auto-immune disease. The major immune response appears to be directed against nuclear antigens. These anti-nuclear antibodies are responsible for the LE cells and immuno-fluorescence on tissue sections.
High probability of SLE • photosensitivity • arthralgia and rash • Raynaud’ or mouth ulcers • pleurisy • proteinuria • haematologicl abnormalities • abortion • any neurological disorder • fatigue / depression
Triggers for SLE • Oestrogens • Sunlight • Infection • Pregnancy • Surgery
SLE: presenting clinical features. Arthritis or arthralgia 55% Skin involvement 20% Nephritis 5% Fever 5% Other 15%
SLE - Non-specific features • Fatigue • Muscle pains • Lymphadenoapthy • Fever • Loss of appetite • Weight loss
Organ involvement in SLE • Joints 90% • Skin • rashes 70% • discoid lesions 30% • alopecia 40% • pleuro-pericardium 60% • kidney 50% • Raynaud’s 20% • mucous membranes 15% • CNS (psychosis/convulsions) 15%
Classification criteria for diagnosis of SLE (>4 of 11) • Neurological disorder • seizure or psychosis • Haematologic disorder • haemolytic anaemia • leukopenia, lymphopenia • thrombocytopenia • Immunological disorder • anti-DNA, anti-Sm • anti-cardiolipin • ANA positivity • Malar rash • Discoid rash • Photosensitivity • Oral ulcers • Arthritis • Serositis • Renal disorder • proteinuria > 0.5g • cells &/or casts
6. Arthritis -arthralgia -symmetrical, non-erosive synovitis -Jacoub’s arthropathy (reducible deformities) -Nodules possible
Raynaud’s phenomenon Livedo reticularis Alopecia diffuse or patchy
7.Renal disease - consider biopsy if: Proteinuria > 0.5 g/24 hours red or white cells in urine casts creatinine clearance reduced (<80ml/min) Proliferative glomerulonephritis Membranous glomerulonephritis
7. Renal disease • Always check urine for protein and blood • Exclude infection/menstruation/ kidney stones • Check serum creatinine/creatinine clearance • Exclude drugs (NSAIDS) • Monitor blood pressure
8. Neurological disease • Peripheral and/or central nervous system • SLE is great mimic • Hemiplegic migraine • Young stroke • Epilepsy • Aseptic meningitis
Cerebral Lupus • Cerebral LE is a serious condition occuring in up to 1 in 6 of SLE patients and can cause prolonged headaches, seizures, strokes, acute psychotic episodes and severe depression. Anyone with cognitive functional defects should be referred for specialist advice.
9. Haematological clues • Leucopenia (lymphopenia > neutropenia) • Thrombocytopenia • Anaemia- not iron deficient • Tests for haemolysis- Coomb’s test haptoglobins reticulocytes
10. Immunological screening tests • CRP versus ESR/viscosity • ANA • RF • IgG, IgA, IgM
11. ANA - Indirect immunofluorescence 1 1 1 • Top left: homogenous Top right: peripheral • Bottom left: speckled Bottom right: nucleolar
Differential diagnosis of SLE • RA • Other autoimmune/connective tissue disease • Infection • Drug-induced condition • Malignancy • Post-viral fatigue syndrome • Fibromyalgia
Further immunological tests • For SLE: anti-dsDNA Abs anti-ENA Abs (Ro, La, RNP, Sm) C3, C4, C3d • For anti-phospholipid syndrome: anti-cardiolipin Abs APTT/Lupus anticoagulant test • (detects prolongation of phospholipid dependent coagulation tests due to antibodies acting as inhibitors of clotting test, despite causing thrombosis in vivo- not reversed by addition of normal serum)
Auto antibodies in SLE to: • dsDNA • 60% patients • increased risk kidney disease • levels fluctuate • RIA, ELISA, Crithidia
Cardiolipin 10–30% Thrombosis Foetal loss Histone Drug induced lupus Sm 10-30% ?kidney and CNS disease RNP 10-30% “Mixed connective tissue disease” (lupus, systemic sclerosis and myositis) Auto antibodies in SLE to:
Ouchterlony – Passive immunodiffusion • Ro and La • 20-60% and 15-40% • rashes & neonatal lupus and congenital heart block
Antiphospholipid antibody syndrome Recurrent venous or arterial thrombosis Recurrent miscarriages Thrombocytopenia Anti-cardiolipin antibodies Circulating lupus anticoagulant (APTT, KCT, Russel Viper Venom test)
Treatment • Sun-block lotions/creams • Artificial tears and saliva • NSAID’s • Corticosteroids • Hydroxychloroquine • Immunosuppressants • Warfarin • Rituximab
Survival rates in SLE 5 years 10 years 15 years 20 years (Abu-Shakra J Rheum 1995) 93% 85% 79% 68%
Primary causes of death in early and late SLE Early Active SLE 26% Infections 37% Other morbidity 19% Unrelated 7% Unknown 11% (Abu-Shakra J Rheum 1995) Late 10% 30% 37% 13% 10%
Other points of interest in SLE • Raynaud’s disease • Septic arthritis • Cardiovascular risk • Osteoporosis • Thrombosis • Malignancy