Systemic Lupus Erythematosus Flashcards
SLE is an autoimmune disease caused by autoantibodies and complement deposition, causing manifestation on skin, joint, multiorgan dysfunction
Epidemiology of SLE
- Female > male (10-15 times)
- Age 15-45 years old
- 3-4 times higher in non-Caucasian (African-American, Asian, Hispanic)
Laboratory hallmark of SLE
- Elevated ANA (very sensitive but not specific)
- Most specific: Peripheral or rim pattern
- Commonest but least specific: speckled pattern
- Nucleolar pattern -> scleroderma - dsDNA - highly specific, correlates with lupus nephritis activity
- Histones (H1, H2A, H2B, H3, H4)
- anti-Sm - highly specific, no activity correlation
- Ribosomal P proteins - highly specific
- Low C3 and low C4
Others:
1. U1-RNP - MCTD
2. Ro/SSA - scleroderma, neonatal lupus
3. La/SSB - scleroderma, neonatal lupus
4. Antiphospholipids
Memorising characteristic manifestations of SLE (ACR 1997 Criteria for SLE)
(SOAP-BRAIN-MD)
S: serositis - pleuritis, pericarditis
O: oral or nasal ulcers
A: arthritis (non-erosive)
P: photosensitivity rashes
B: blood disorders - haemolytic anaemia, leukopenia, lymphopenia, thrombocytopenia
R: renal involvement: proteinuria, cellular casts
A: ANA
I: immunologic - dsDNA, anti-Sm, APLAs
N: neurologic - seizures, psychosis
M: malar rashes
D: discoid rashes
ACR/EULAR Classification of SLE (2017)
Highly sensitive (96%), specific (93%)
Mandatory ANA + at least 10 point criteria
Mandatory criteria:
1. ANA titre > 1:80
Points criteria (at least 10 points):
- Do not count if due to other cause than SLE
- at least 1 clinical criterion
Clinical
1. Renal involvement
- Class 3/4 nephritis - 10
- Class 2/5 nephritis - 8
- Proteinuria >0.5g/day - 4
- Arthritis - 6
- Serosal
- Pericarditis - 6
- Pleural or pericardial effusion - 5 - Mucocutaneous
- Cutaneous lupus - 6
- Subacute cutaneous or discoid lupus - 4
- Oral ulcers - 2
- Non-scarring alopecia - 2 - Neuropsychiatry
- Seizure - 5
- Psychosis - 3
- Delirium - 2 - Haematologic
- AIHA - 4
- Thrombocytopenia - 4
- Leukopenia - 3 - Constitutional - Fever - 2
Laboratory
1. SLE-specific antibodies
- anti-dsDNA or anti-Smith - 6
- Complement proteins
- Low C3 and C4 - 4
- Low C3 or C4 - 3 - Any APLAs - 2
Describe the different types of lupus
A. SLE
- Multiple organs can be involved
- ANA and SLE specific antibodies
- Variable prognosis
B. Subacute cutaneous SLE
- Skin only involvement
- ANA negative, SSA or SSB positive
- 5-10% eventual progress to SLE
C. Drug-induced lupus
- Systemic but without CNS or renal
- Anti-histone antibodies
- Improves when drug stopped
D. Discoid lupus
- Skin only involvement
- ANA negative
- Rarely progresses to SLE unless ANA turns positive
ANA-negative SLE
Rare
- Must have excluded less sensitive test
(must run ANA using HEp-2 assay) - Positive cytoplasmic antigens - antibodies to SSA/Ro-52kD (TRIM-21) or ribosomal P
- Severe proteinuria (loss of Igs and unable to bind to HEp-2)
-> ANA turns positive with treatment - Post-cytotoxic therapy in remission
Risk factors for SLE
- Environmental
- Smoking, viral (EBV, CMV), silica, UV light, pesticides, gut microbiome, demyelinating drugs - Genetics
- First degree relatives with SLE
- Identical twins
- MHC - HLA DR2, DR3
- Complement deficiency - Gender and hormone
- Women of childbearing age
- Klinefelter (14 fold risk)
- Rare in Turner’s syndrome
Pathogenesis of CNS manifestation of SLE
Diffuse manifestation - transient, reversible with therapy
Focal manifestation - permanent, pathological lesions on autopsy
Possible endothelial dysfunction
- Complement activation during acute lupus
- Progoagulant factors (APLAs)
- Thrombosis and emboli
- Microvasculoparhy and disruption of BBB
- Influx of cells, autoantibodies and cytokines into CNS
Associated autoantibodies:
1. Antiphospholipids
2. Antineuronal
2. Ribosomal P
4. NMDA receptor
5. AQP4/NMO
What are the neuropsychiatric manifestations of SLE?
- Diffuse
- Focal
Diffuse
1. Acute confusional state and coma
2. Cognitive dysfunction and dementia
3. Psychosis, depression, anxiety
4. Intractable headache (pseudotumour cerebri)
5. Aseptic meningitis
Focal
1. Stroke syndromes
2. Seizures
3. Chorea, ataxia, hemiballismus
4. Demyelinating syndromes
5. Transverse myelitis
Approach to SLE patient presenting with neuropsychiatry changes
Differential diagnoses:
1. Neuropsychiatric SLE
2. Prednisolone incuded psychosis
3. Delirium - infection
4. Metabolic abnormalities
5. Primary mental illness not due any secondary causes
Evaluation:
1. Signs and symptoms for SLE, localise infections
2. Examination for focal neurological deficits
3. Labs and imaging to exclude infection
4. Check SLE labs: C3/C4, anti-dsDNA levels
5. Consider specific NPSLE serologies: anti-ribosomal P, anti-NMO
6. Lumbar puncture, OP, CSF testing
7. MRI brain +/- spinal cord +/- angiogram/venogram
8. EEG
Respiratory manifestation of SLE
- Pleuritis (commonest)
- Bilateral involvement. Elevated CRP. Consider infection - Acute lupus pneumonitis with/without pulmonary haemorhage
- Ground glass changes. Associated with APLAs
- Progressive to ILD
- Broncoscopy: DAH +/- infection - ILD/fibrosis
- Rare in non-overlap SLE, common in MCTD or prior lupus pneumonitis
- Medication effect (nitrofurantoin) or overlap with anti-synthetase antibody syndrome - Pulmonary hypertension
- Shrinking lung syndrome - reduced lung volume
- A/w phrenic neuropathy, myopathy, pleural fibrosis - Crytogenic organisign pneumonia
- Responsive to steroids
- Overlap with anti-synthetase antibody syndrome - Infections, especially atypicals
- Tree in bud appearance
Cardiac manifestations in SLE
- Pericarditis +/- left pleural effusion
- Treat with colchicine - Myocarditis (rare)
- Presents as heart failure, tachycardia. Elevated trops
- Consider myocardial biopsy - Coronary vasculitis (rare)
- Secondary atherosclerotic CAD and MI (commonest)
- Secondary hypertensive disease - kidney failure, chronic steroids use
- Medication induced cardiomyopathy - hydroxycholoquine
- Valvular disease in APS
- Libman-Sacks endocarditis/verrucae
- Posterior leaflet of mitral valve or aortic valve
- Leads to embolic stroke
- high concomitant subacute bacterial endocarditis
- TEE more sensitive than TTE
Gastrointestinal manifestations of SLE
Usually rare, and unlikely due to SLE
UNLESS patient has active SLE in other organs and abnormal serologies
- Oesophageal dysmotility
- Upper 1/3 involvement, esp in SLE myositis, overlap syndromes - Pancreatitis - usually non SLE related (gallstones, alcohol, hyperTG)
- Medication (azathioprine)
- Diffusely active if due to SLE - Serositis
- Mesenteric vasculitis, bowel oedema, fat stranding
- Associated with active SLE - Hepatitis - from mediaction, or non-lupus
- Must not have anti-smooth muscle and anti-LKM if due to SLE - Intestinal pseudo-obstruction
- Protein losing enteropathy
- Low albumin without proteinuria
- Chronic diarrhoea, generalised oedema
- Diagnosed with fecal alpha-1 antitrypsin or transferrin
What are the indications for renal biopsy in SLE patient?
What is the importance of biopsy?
Indications
1. Increasing creatinine without alternative cause
2. Proteinuria > 1g/day
3. Proteinuria >0.5g/day wtih haematuria or cellular casts
Importance of biopsy
1. Histologic changes of chronicity - scarring, fibrosis indicates less likely responsive to therapy
2. Evaluate for microthrombotic disease in APS
3. Calculated scoring on disease activity (mixed predictive value, no longer universally use)
SLE Glomerulonephritis Classification Sytem (2004)
Class I - minimal mesangial
- No clinical manifestation
- Histology: mesangial immune deposits on IF / EM
Class II - mesangial proliferative
- Microscopic haematuria, proteinruia, rare HTN
- Histology: mesangial hypercellularity or matrix expansion, few subepithelial/subendothelial deposit
Class III - focal (A: active; C: chronic)
- Haematuria, proteinuria, HTN
- Reduced GFR or nephrotic syndrome
- Histology: < 50% glomeruli affected; almost uniformly involved. EM - immune deposits, some mesangial and some subedothelial space
Class IV - diffuse (S: segmental; G: global; A and C)
- Haematuria, nephrotic range proteinuria
- Cellular casts, reduced GFR, HTN
- Hypocomplementaemia, elevated dsDNA
- Histology: > 50% glomeruli involvement; generalised hypercellularity of mesangial and endothelial cells; extensive deposition. EM immune complxes in both subendothelial and subepithelial
Class V - membranous
- Extensive proteinuria, minimal haematuria
- Minimal renal function abnormalities
- Histology: granular global or segmental subepithelial immune deposits
Class VI - advanced sclerosing
- CKD
- Histology > 90% global glomerulosclerosis without residual activity
Serologic tests for lupus nephritis follow up
- dsDNA - elevates with disease flare
- Complement levels - decrease with active disease
(Some patients have chronic partial C4 deficiency, thus C3 might be more useful for follow up) - ANCA - perinuclear (PR3)
(MPO not useful)
Caveats:
Some patients can develop GN even with normal complements and no dsDNA
What are risk factors for SLE nephritis progression to ESRF?
- African american, Hispanics, especially males
- Low SES
- Poor medication compliance
- Pooly controlled comorbids: DM, HTN
- persistent elevatec creatinine or failure to normalise on therapy
- Persistent proteinuria > 6 months of treatment
- Renal biopsy - crescent (high disease activity) or interstitial fibrosis (chronic)
Pathologic scoring of lupus nephritis
Based on chronicity and activity
Chronicity
1. Glomerular sclerosis
2. Fibrous crescent
3. Fibrous adhesions
4. Interstitial fibrosis
Activity
1. Cellular proliferation
2. Fibrinoid necrosis
3. Cellular crescents
4. Hyaline thrombi
Treatment for severe lupus nephritis
- To note: different for SLE without severe nephritis
- Class III/IV treatment differs from class V
Class III and IV lupus nephritis - induction and maintenance
Induction therapy
1. IV methylprednisolone 500mg-1g OM for 3 days
2. Followed by prednisolone 1mg/kg/day (crescent) or 0.5mg/kg/day (no crescent)
- Taper after a few weeks to lowest effective dose
3. Immunosuppressives: choice of
A. MMF 2-3g/day for 6 months (better in Hispanics, African)
B. IV cyclophosphamide
(NIH high dose regime: 500-1000 mg/m2 monthly x6)
(Eurolupus low dose regime: 500mg every 2 weeks x6)
- Consider switching if fail to improve on MMF -> Cyc and vice versa. And if fail, consider rituximab or CNI
Class V lupus nephritis
1. Oral prednisolone 0.5mg/kg/day for 6 months
2. MMF 2-3g/day for 6 months
3. Add on CNI (tacrolimus, cyclosporin) if needed
4. IV cyclosporin if treatment fails
Maintenance post-induction - adjucts
1. Hydroxycloroquine, azathioprine
2. ACEi or ARBs if proteinuria > 0.5g/day, control BP < 130/80
3. Statin
4. Stop smoking
5. Counsel against pregnancy while in active nephritis or teratotoxic drugs
6. Rituximab
Considerations for high dose vs low dose cyclophosphamide (NIH high dose vs Eurolupus low dose)
Low dose
Pros: fewer serious infections, lesser infertility (premature ovarian failure), lesser bladder toxicity
Cons: higher rate of fail to respond
Premature ovrian failure and bladder cancer correlates with cumulative dose (>10-15g total) and age (>30 years)
Emerging studies:
CALIBRATE study - rituximab 1g + cyc 500-750mg + belimumab (not promising)
Cyclophosphamide infusion protocol
A. Pre-medications
1. +/- Dexamethasone or hydrocortisone
2. Anti-emetics: metoclopramide or ondansetron
B. Adjuncts
1. Mesna - pre-dose as IV, post-dose as oral x2
- Reduces risk of haemorrhagic cystitis
2. Premature gonadal failure prevention
- IM Gonadotropin-releasing hormon (Lupron) 3.75mg, 10 days prior to CYC … or
- IM testosterone 200mg 2 weekly
- Progression of lupus nephritis to ESRF
- Survivability of ESRF lupus nephritis on dialysis
- Lupus nephritis recurence post-transplantation
25% lupus nephritis progress to ESRF over 10 years
(1-2% of all ESRF cases)
Clinical course and survival on dialysis favourable (80-90% 5 year survival)
Excellent candidate for transplantation
- Living donor better than cadaveric
Recurrence: 2-11%
- And recurrence unlikely lead to allograft loss
- Retroanaluysis - similar incidence of graft survival rates as non-lupus patient, except in APS (thrombosis)
Haematologic manifestations of SLE
- AIHA
- Leukopenia (lymphopenia, neutropenia)
- Thrombocytopenia
- APS
- Anaemia of chronic disease
- Thrombotic thrombocytopenia purpura (TTP)
- Macrophage activation syndrome (MAS)