Systemic lupus erythematosus

Question 1

what is SLE?

Answer 1

• autoimmune disease
• Autoantibodies are made against a variety of autoantigens (eg ANA) which form immune complexes. Inadequate clearance of immune complexes results in a host of immune responses which cause tissue inflammation and damage.
• inadequate T cell suppressor activity with
  increased B cell activity
• most patients have antibodies to certain cell
  nucleus components
• characterized by remissions and flares.
• can be familial

Question 2

what are some common signs and symptoms of SLE? (SOAP section of SOAP BRAIN)

Answer 2

SOAP BRAIN

Serositis - Pleurisy, pericarditis

Oral ulcers - painless, palate usually.

Arthritis - in small joints, non erosive

Photosensitivity - of malar/discoid rash

Question 3

what are some common signs and symptoms of SLE? (BRAIN section of SOAP BRAIN)

Answer 3

SOAP BRAIN

Blood disorders - Low WCC, lymphopenia, thrombocytopenia, haemolytic anaemia

Renal involvement - glomerulonephritis

Autoantibodies (ANA positive in most cases)

Immunological tests e.g low complements

Neurological disorders e.g seizures or psychosis

Question 4

what do investigations into SLE show?

Answer 4

• raised ESR or plasma viscosity (CRP normal)
• anaemia and leukopenia are common
• most are ANA positive
• Anti Ro and Anti La are common
• Anti dsDNA titre rises with disease activity
• anti-phospholipid antibodies present (also increase risk of pregnancy loss and thrombosis)
• C3, C50 and C4will fall with disease activity
• urinalysis to detect renal disease
• +ve direct coombs test
• skin biopsy can be diagnostic
• renal biopsy can be diagnostic and can help determine prognosis

Question 5

how is SLE treated?

Answer 5

• Sun protection
• Advice on healthy lifestyle in view of cardiovascular risk
• Hydroxychloroquine is helpful for rash and
  arthralgia (and also NSAIDs unless renal disease)
• Mycophenolate mofetil, azathioprine and
  rituximab are commonly used too
• Short courses of prednisolone for flares

Question 6

what drugs can trigger an SLE like syndrome?

Answer 6

isoniazid, minocycline and TNF inhibitors

Question 7

how is SLE disease activity monitored?

Answer 7

1) anti dsDNA antibody titres
2) complement, C3 and C4
3) ESR, also BP, urine for cast or protein, FBC, U&E, LFTS, CRP

(think SLE when someone has a multisystem disorder but CRP is normal and SLE is raised)

Question 8

how is lupus nephritis treated?

Answer 8

• immunosuppression with steroids and cyclophosphamide or mycophenolate
• BP control
• RRT may be needed in disease progression