SLE Flashcards
What are risk factors associated with SLE?
The exact etiology is unknown, but several predisposing factors have been identified.
Genetic Predisposition
- HLA-DR2 and HLA-DR3 are commonly present in individuals with SLE.
- Genetic deficiency of classical pathway complement proteins (C1q, C2, C4) in approx. 10% of affected individuals
- Hormonal factors: Hyperestrogenic states (e.g., due to oral contraceptive use, postmenopausal hormonal therapy, endometriosis) are associated with an increased risk of SLE.
- Environmental factors
Cigarette smoking and silica exposure increase the risk of developing SLE.
UV light and EBV infection may trigger disease flares, but there is insufficient evidence on whether they cause SLE.
More common in FEMALES
Female: 10:1
Interestingly, patients with turner’s + klinefelters - less SLE
Clinical features of SLE
Non specific: fatigue > fever > weight loss
Joint:
- arthralgia + arthritis
- migratory, polyarticular and symmetrical. Normally affects knees, wrists, finger joints.
- Unlike RA, morning stiffness is less prominent and non-deforming/erosive
- Jaccoud’s arthropathy: tenosynovitis
- Rhupus: RA/SLE overlap
- Less common: myalgia, avascular necrosis
Mucocutaneous
- Acute (non-scarring): Malar rash
- Subacute: Photosenstivity: maculopapular rash
- Chronic: discoid rash, scarring can occur
- Non-scarring alopecia, usually diffused and related to disease activity. Lupus fizz (thin brittle hair around hairline).
- Oral ulcers (usually painless)
Vascular
- Raynauds
- Small vessel vasculitis: palpable purpura, livedo reticularis
Cardiovascular:
- Pericarditis most common
- Myocarditis
- Libmann sach’s endocarditis
- Valvular disease - mitral > aortic, regurgitation> stenosis
- Coronary artery disease, increased risk
Lung:
- pleuritis
- ILD
- Pneumonitis
Haem
- Anaemia
- Leukopenia
- Thrombocytopenia
- Evans syndrome: autoimmune haemolysis + ITP
Neuropsych
- Cognitive decline (lupus fog) > headache > mood disorder > CVA > myelitis
Lupus nephritis
Cause of drug induced SLE
Anti histone My Two HIPs - Methyldopa - TNF-a inhibitiors - Hydralazine - Isoniazid - Procainamide/Phenytoin - Sulfa drugs, eg: bactrim
Characteristics of lupus nephritis
- Most dangerous organ complication and common cause of death in SLE
- Can present as nephritic or nephrotic
- Mesangial or subendothelial deposition of immune complexes (anti-dsDNA, anti-sm) –> expansion and thickening of mesangium/capillary walls and GBM
- HTN, oedema, haematuria
- Proteinruia, haematuria, cellular casts
Tx: corticosteroids, immunosuppressants (mycophenolate, cyclophosphamide), ACEi
Autoantibodies involved in SLE
ANA > 1:80 (speckled)
ANA: 98%; Best screening test
- dsDNA ab: 70%: High titers are SLE-specific and in some patients correlate with disease activity, nephritis, vasculitis
- Anti-Sm (25%): SPECIFIC for SLE; no definite clinical correlations
- Anti-Ro (SSA): 30%; Not specific for SLE; associated with sicca syndrome, predisposes to subacute cutaneous lupus,neonatal lupus, photosensitivity, C2 deficiency. Also sjogrens.
- Anti-La (20%); a/w lower risk of nephritis . Also sjogrens
- Anti-histone antibodies (70%): Drug induced lupus
- Anti-phospholipid syndrome: Lupus anticoagulant >cardiolipin Ab> B2 glycoprotein Ab
- Ribosomal P ab: neurolupus
- U1RNP: mixed connective tissue disease (needs to be on its own for mixed)
Other: - Hypocomplementaemia, normally C4 Low C3/ complement levels (C3, C4) are low during active disease (formation of complexes leads to consumption of complement) - ESR>CRP - Positive RF
What are the SLE specific antibodies?
Anti-dsDNA antibody
- Positive in 60-70% of patients and highly specific for SLE
- Levels correlate with disease activity
- Associated with lupus nephritis
- Associated with subacute cutaneous SLE
Anti-Sm Ab
- Positive in <30% of patients but highly specific for SLE
Diagnostic criteria
4 lab, 7 clinical 4/11
MDBRAINSOAP
4 Lab
- Bloods: haemolytic anaemia with reticulocytes, thrombocytopenia, leukopenia, lymphopenia
- Renal disorder: protein > 0.5h/day, cellular casts
- ANA
- Immunological manifestations
Antiphospholipid ab: lupus anticoagulant, anticardiolipin, anti B2 glycoprotein
Low C3/C4
Anti dsDNA, anti smith
7 clinical
- MUCOCUTANEOUS signs: malar rash (sparing nasolabial fold), discoid rash, photosensitive rash, oral/nasal ulcers (painless)
- SEROSITIS: pleuritis, pericarditis
- ARTHRITIS, non erosive small joint polyarthritis - Jaccoud’s arthritis
- Neurological disorders: seizures/
‘SOAP BRAIN MD’
Serositis: pleurisy or pericarditis
Oral ulcers
Arthritis
Photosensitivity
Blood: anaemia, leukopenia, lymphopenia and thrombocytopenia
Renal disorder: lupus nephritis - minimal mesangial, mesangial proliferative, focal, diffuse, membranous and advanced sclerosis
Antinuclear antibody
Immunology: anti-Smith, anti-ds DNA and antiphospholipid antibody
Neurologic disorder: seizures or psychosis
Malar rash
Discoid rash
Mixed connective tissue disease
SLE, systemic sclerosis (SSc), and polymyositis (PM)
High RNP Ab - infrequent development of diffuse proliferative glomerulonephritis, psychosis, or seizures; with the early development of Raynaud phenomenon in nearly all patients
Non-pharmacological management of SLE
Avoid triggers:
- Stress
- UV light (photoprotection)
- Oestrogens/OCP.
- Vitain D repletion
- Cease smoking, diet, exercise
- Immunisation
UV protection
Smoking cessation
Immunisation
Pharmacological management for SLE
Basic therapy: hydroxychlorquine, and addition of methotrexate or azathioprine if no response
Inductive Therapy
- Mild symptoms, no organs affected: glucocorticoids
- Severe symptoms, no vital organs: medium dose oral glucocorticoids
Immunosuppressive agents: mycophenolate, cyclophosphamide
Biologicals: belimumab (B cell inhibitor)
- Organ damage: IV steroids and above immunotherapy + biologicals
- Corticosteroids
- Methotrexate
- Azathioprine
- Leflunomide
- Mycophenolate - especially renal/pulmonary
- Cyclosporin
Benefits and side effects of hydroxychloroquine
- B/G therapy for all patients - indicate in all patients
BENEFITS:
- Decreased flares
- Decreased progression to renal nephritis + CNS lupus
- Decrease organ damage
- Doubles response to MMF
- CVS protection
- Decrease thrombosis
- Protect against CHB in SSA+ mothers
- Improved overall survival
- MOA
Increase lyosomal pH
Inhibits TLR9 on APC/dendritic cells and prevents the TH17 response by reducing IL-17 and IL-23
SE
- Immunomodulatory, not immunosuppressive
- RETINOPATHY - is cumulative dosing, “bull’s eye visual field loss”
- Haemolytic anaemia in G6PD
- Aggravates psoriasis
- Myelosuppression
MOA of belimumab
Monoclonal ab that binds to soluble BAFF/BLys (B cell activating factor/B lymphocyte stimulator) which is a critical factor in the regulation of B cell survival and differentiation
Treatment for Raynauds
Verapamil
Treatment for lupus nephritis
Class I, II, VI – no immunosuppression
Class III, IV (+/- V) – immunosuppression
Induce with IV methylpred for - 3 days and MMF/CYC
- Maintain: AZA/MMF/CYC
- If refractory: Rituximab / Tacrolimus
Serological monitoring – rising dsDNA can predict clinical relapse
ACEi, aim LDL<2.6, BP <130/75
Novel therapies for SLE management
- Rituximab: chimeric anti-CD20 monoclonal antibody that binds to CD20 on B lymphocytes and starts an immune response that lyses normal and malignant B cells. Apoptosis is also induced. Regeneration of normal B lymphocytes occurs
Infusion reaction: Occur 30–120 minutes after starting infusion and include fever, chills and/or rigors, nausea, vomiting, urticaria, itch, headache, bronchospasm, dyspnoea, angioedema, rhinitis, hypotension
Lymphopaenia, recovery starts at 6 months post cessation - Belimumab: Human mAb that binds to soluble BAFF/BLyS, which regulates B cell proliferation and differentiation
SE: infections, hypersensitivity and infusion-related effects (below), diarrhoea, nausea, leucopenia, depression, anxiety
Anifrolumab: Anti-IFN receptor mAb -IFN therapies