MSPA: Rheumatology- Diffuse Connective Tissue Diseases Flashcards
What is SLE ?
It is an immune complex mediated Type 03 HSR manifests as autoimmune multisystem inflammatory disease with prominent clinical presentation of rashes and arthralgia as well as serious renal and cerebrovascular complications.
What is the epidemiology of SLE
It is nine times more common in woman than in men with a peak age of onset between 20 and 40. It is more prevalent in African/ Caribbean woman (1:250) followed by hispanics and asians.
what are the most common causes of death in Lupus ?
*Renal disease (7.9x gen population)
* Infection (5x gen population)
* Haematologic malignancies and lung CA (2.1x gen pop)
* Cardiovascular disease (1.7x gen pop)
What is the etiology of SLE ?
The exact cause is unknown and genetic factors are being considered.
What is the pathophysiology of SLE ?
The UVA induced damage causes skin cell apoptosis. The intracellular remnants of the dead cells appear on the cell surface as small blebs of self antigens consist of DNA and histone. The genetic defects in cellular phagocytic mechanisms in SLE patients causes the development of antibodies against these antigens leading to the formation of antigen- antibody complexes ( Immune complexes) which circulates throughout the body and gets deposited in various tissues causing systemic symptoms of SLE.
What are the systemic pathophysiological effects of antigen -antibody complex ( immune complex) deposition on various tissues in SLE?
These immune complex depositions triggers local inflammation such as the ones seen in lupus nephritis. Pancytopenia due to deposition on RBCs, WBCs and Platelets. In addition compliment depletion occurs due to high demand on complement system to destroy immune complex deposited cells.
what type of hypersensitivity reaction is antigen- antibody complex formation which is the core of SLE pathohysiology?
The antigen- antibody complex formation is Type 2 HSR. The Antigen- antibody complex deposition mediated pathological process are Type-3 HSR.
What are the signs of SLE ?
- Nonscarring Alopecia
*Malar rash
*Discoid rash - Photosensitivity
- oro-nasal mucosal lesions.
- Serositis
- Myocarditis
- Libman-Sacks endocarditis.
- Non-erosive symmetrical polyarthritis.
What are the non- treatment requiring SLE nephritis subtypes ?
Type 01 messangial and type 02 messangial proliferative SLE nephritis have no symptoms or laboratory abnormalities. Therefore, they don’t require treatments.
What are the aggressive treatment requiring lupus nephritis types ?
Focal proliferative (III) and diffuse proliferative (IV).
What are the lab findings in Type 3 and 4 lupus nephritis ?
HTN, protein urea, active sediments, + Anti-dsDNA antibody, elevated Cr and urea, Low C3/C4.
What are the findings in type 5 or membranous lupus nephritis ?
Heavy protein urea and bland sediments. It needs to be actively treated.
What is the prognosis of type VI ( advanced sclerosing Lupus Nephritis )?
ESRD
What are the neuropsychiatric effects of SLE ?
*Headache
* Seizures
* Psychotic disorders
* Mood disorders
* Stroke
* Peripheral neuropathies
What are the hematological laboratory findings seen in SLE?
- Anaemia of chornic disease due to Renal disease associated erythropientin response insufficiency.
- Iron deficiency anaemia
- Hemolytic anaemia
- Leukopenia and thromobocytopeania
- In many cases pancytopenia
What are the typical markers seen elevated in SLE ?
- ANA
*Anti-dsDNA - Anti-smith Antibody
- Anti-phospholipid antibodies- Anti-cardiolipin, lupus anti-coagulant, Anti-β 2 glycoprotein 1 antibodies.
- Low C3 and C4
- Anti-histone antibody in drug induced lupus.
What is the sensitivity and specificity of ANA in SLE ?
95% sensitivity, but low specificity.
What is the sensitivity and specificity of Anti-dsDNA and anti-smith antibodies in SLE ?
Low sensitivity but high specificity with active disease
Anti-histone antibody is specific to what type of lupus ?
drug induced lupus.
What is the diagnostic criteria for SLE ?
It is predominantly a clinical diagnosis based on the clinical presentation consistent with SLE which is not explained by other conditions and an ANA titer > 1:80.
What are the initial laboratory work-ups in SLE ?
- FBC
- Serum creatinine
- UA with microscopy
- ANA
What is the general management of SLE ?
- Limit sun exposure and use high factor sunblock.
- Adequate intake of calcium and vitamin D
What is the management of mild SLE that presents with mucocutaneous lesions and arthritis only?
- NSAIDs
- Hydroxychloroquine (PLAQUENIL®)
- Hydroxychloroquine (PLAQUENIL®) + NSAIDs
*Occasional short course of low dose
steroids (e.g., 5 mg prednisolone).
What is the management of moderate SLE that presents with symptoms of mild SLE and serositis without nephritis ?
Hydroxychloroquine + Oral steroids (short term).
What is the management of severe SLE that presents with symptoms of moderate SLE and nephritis with severe symptoms?
Immunosuppressant such as:
▪ Cyclophosphamide
▪ Azathioprine
▪ Methotrexate
▪ Mycophenolate
▪ Rituximab
*RUXIENCE
What is the pathogenesis of drug induced lupus ?
Many drugs can induce the formation of Ab-AG immune complex which can lead to similar symptoms as SLE rash, arthritis, serositis with notable absence of blood, kidney and braininvolvement.
what is the management of drug induced lupus ?
stop drug, NSAIDs,
topical steroids.