Approach to Types of Vasculitis -- Easy review notes of Large, Medium, Small vessel and other Vasculitides

 ⒸPathologynuggets. Notes to review for medical students, residents, and doctors.

Vasculitides are autoimmuine disorders characterized by inflammation of blood vessels.
Most of them are chronic systemic disorders that affect the multiple systems and should be considered in differential diagnoses of any multisystem illness.

Vasculitis can be divided into large vessel, medium vessel or small vessel
vasculitis based on the size of the vessels involved.

Large Vessel Vasculitis

‌Giant cell arterities or Temporal arteritis

Takayasu arterities

Medium Vessel Vasculitis

‌Polyarterities Nodosa

Kawasaki Disease

Small Vessel Vasculitis

‌Granulomatosis with Polyangitis(GPA)

‌Microscopic polyangitis (MPA)

‌Eosinophilic Granulomatosis with Polyangitis (EGPA)

            ** Small vessel vasculitides GPA, MPA and EGPA are also known as ANCA                                     associated vasculitides (AAVs). **
Immune complex small vessel vasculitides

‌    IgA vasculitis

    Cryoglobulinemic vasculitis

Variable Vessel Vasculitis

‌Bechet disease

Cogan Disease

Vasculitis Associated with Systemic Illness

‌SLE

RA

‌Sarcoid, etc.

Investigations:

Variety of investigations are useful in evaluation of vasculities. Some of the commonly sent investigations and related findings are listed below:

CBC                     anemia, thrombocytosis
ESR, CRP            frequently increased
Creatinine         increased in renal involvement
Urinalysis         may show casts, hematuria
Liver enzymes
ANCA Screen    GPA, MPA and EGPA are ANCA associated
                            c-ANCA or proteinase 3 reactive in GPA
                            p-ANCA or MPO reactive in MPA and EGPA
        ** p-ANCA is non specific and is also seen in IBD, connective tissue disorders**
Hepatitis B & C Serology
        PAN is associated with Hep B
        Cryoglobulinemia is associated with Hep C, HIV
Complement levels
Chest X-Ray
CTA or MRA for medium or large vessel vasculitis
Biopsy

Important points about features, investigations, diagnosis and treatment of  vasculitides:

Some of the important points of different vasculitis are listed below. Please read articles of individual disease for more detailed review.

GCA also known as temporal arteritis: new onset headache in women age >50 yr,  ESR >= 50 mm/h, temporal artery tenderness or decreased pulse, jaw claudication, biopsy shows vasculitis with mononuclear infiltrate, or granulomas, with multinucleated giant cells, PMR symptoms in 40%, Rx: steroids, low dose aspirin, chronic disease requiring long term Rx, Complications:Aortic aneurysm of thoracic aorta, rupture, long term monitoring for aortic aneurysms

Takayasu Arteritis: asian women <40yr, aorta and its major branches carotid, vertebral,  upper extremity claudication, brachial pulse decreased or asymmetrical, BP difference in arms >=10 mm Hg, Complication: aneurysm, rupture, stenosis, cardiac ischaemia, stroke

Polyarteritis Nodosa or PAN : medium sized vessel, Hep B, Minocycline,  multysystem but absence of lung involvement, ANCA negative, Dx Angiography or biopsy Rx corticosteroids +/- cyclophosphamide. Use corticosteroids + antivirals if Hep B positive.

Necrotizing granulomas are seen in GPA and EGPA (note granulomatosis in their name)

GPA :       mnemonic ELKS: Ear, nose, and throat; Lung; Kidney; Skin, c-ANCA
MPA :       p-ANCA +ve, lung,kidney, skin
EGPA :     p-ANCA +ve, granulomas, allergic rhinitis and asthma, less renal involvement                     but more cardiac involvement, eosinophilia( > 10% eosinophils in blood)
Rx of small vessel vasculitides: 1. Remission Induction: cyclophosphamide + corticosteroids. Nowadays Rituximab, anti CD20 antibody, has replaced cyclophosphamide. 2. Remission maintenance: Methotrexate (contraindicated in CKD) and azathriopine, patients on immunosuppression should receive prophylaxis against pneumocystis jiroveci.

IgA Vasculitis: palpable purpura in lower extremities and buttocks, arthralgia or arthritis, abdominal pain and hematuria, pediatric or adults, higher risk of renal disease in adults, no specific biomarker, Rx self limiting condition, supportive treatment, role of steroids is controversial

Cryoglobulinemia: elevated Ig levels, low complement levels, serum protein electrophoresis and immunoelectrophoresis may show monoclonal or polyclonal, blood should be drawn in prewarmed syringe and vials, many associations: HepC, hematologic malignancy : multiple myleoma, Waldenstrom macroglobulinemia, and lymphomas, SLE, Sjogren

Differentials of palpable purpura:
MPA
EGPA
GPA
IgA vasculitis (or Henoch Schonlein purpura)
Cryoglobulinemia
Drug associated
Vasculitis associated with RA, SLE, Sjogren