Relapsing Polychondritis Flashcards
Relapsing polychondritis pathogenesis
Activated lymphocytes and macrophages → release of lysosomal enzymes (eg proteases) against cartilage components (collagen type 2, 9, 11, matrilin 1 - found exclusively in resp tract and ears), and proteoglycans → destruction and attempt at repair by local fibroblasts and chondrocytes → granulation tissue and fibrosis
RPC (relapsing polychondritis) histopath
Cartilage matrix acidophilic (pink) with hamtoxylin and eosin staining (usually basophlic and blue)
-Inflammatory cell infiltrates (PMN, lymph, plasma cells) invade cartilage from periphery
-Granulation tissue and fibrosis adjacent to inflamm infiltrates
-Electron microscopy: increased lipids and lysosomes in chondrocytes on
-Immunofluorscence: Ig and complements
When to bx RPC
- Lack of multiple sites of targeted cartilage involvement
– Failure to resp to pred / dapsone
– Features concerning for alt dx
DIagnostic criteria RPC
McAdam 3/6 OR 1/6 + histology OR 2/6 + response to steroids/dapsone:
– Bilat auricular chondritis
– Nonerosive seroneg inflamm polyarthriits
– Nasal chondritis
– Ocular inflamm
– Resp tract chondritis
– Audiovestibular damage
-Michet: 2maj or 1maj+2minor
-Major:
– Proven inflamm episodes involving auricular cartilage OR
– Nasal cartilage OR
– Laryngotracheal cartilage
-Minor:
– Ocular inflamm (conjunctivitis, keratitis, episcleritis, uveitis)
– Hearing loss
– Vestibular dysfcn
– Seroneg inflamm arthritis
** RPC clinical manifestations**
Auricular chondritis
-Arthritis (oligo/poly, nonerosive, asymmetric)
-Tenosynovitis
-Nasal chondritis
-Ocular inflamm
-Laryngotracheal sx (eg laryngeal, epiglottal edema, choking, stridor, SOB, resp failure,t racheal stenosis)
-Reduced hearing
-Vestibular dysfcn
-Saddle nose
-Cutaneous
-Laryngotracheal stricture
-Vasculitis
-Costochondritis (SC, CC, SM joints; flail chest)
-Recurrent respiratory infxn
** Ocular inflamm RPC**
Episcleritis,
-Scleritis,
-Necrotizing scleritis,
-Lid edema,
-Orbital inflamm dz,
-Conjunctivitis,
-Uveitis,
-Peripheral ulcerative keratitis,
-Retinal vasculitis,
-Optic neuritis
-Cataracts
-Proptosis
-Corneal ulcerations /thinning
-EoM palsy
Audiovestibular Mx RPC
Hearing loss (conductive from inflam edema or collapse of external auditory canal or eustacian tubes or sensorineural from inflam of internal auditory artery)
-Tinnitus
-Vertigo
-Fullness in ear (from serous otitis media)
Cardiac Mx RPC
Aortic insuff from DILATION of root
-Pericarditis
-Myocarditis
-Arrhythmia
-Coronary aneurysm
-Valvulitis
-Conduction defects
DDx valvulitis
Rheum fever
-RA
-AS
-ReA
-Behcet
-Endocarditis
DDx dilation of valve ring
Marfan
-Syphilis
-RPC
-Dissecting aneurysm
-Idiopathic
-Takayasu
-GCA
-Cogan
** RPC Derm Mx**
Oral aphthosis ~Behcet (MAGIC)
-LCV
-Erythema nodosum
-Alopecia
-Abnormal nail growth
-Superficial thrombophlebitis
** RPC Neuro Mx**
Cranial neuropathy
-H/A
-Seizures
-Aseptic meningitis
-Encpahlopath
-Hemiplegia
-Ataxia
** RPC Renal Mx**
Elevated Cr
-Microhematuria
RPC Lab Mx
Inflamm markers
-High WBC, Plt
-Chronic anemia
-Increased alpha & gamma globulins
-Low titre RF, ANA, ANCA
-AB to type 2 collagen
RPC radiographic abN
XR: tracheal air column (tracheal stenosis), periarticular osteopenia (nonerosive)
-CT/MRI: tracheal narrowing nad inflamm