Vasculitis refers to inflammation of blood vessels. It can be caused by direct infection, immune complexes, or antibodies. Types include large vessel vasculitis like giant cell arteritis, medium vessel vasculitis like polyarteritis nodosa, and small vessel vasculitis like Wegener's granulomatosis. Giant cell arteritis most commonly affects those over 50 and causes headaches, vision loss, and temporal artery inflammation. Polyarteritis nodosa involves small and medium arteries and can cause fever, weight loss, and kidney involvement. Wegener's granulomatosis is characterized by lung and respiratory tract inflammation and kidney disease.

1. Vasculitis Dr Basavaraj P Bommanahalli Assistant Professor Dept of Pathology SSIMS RC Davanagere Karnataka

2. Def: inflammation of wall of the vessels c/f constitutional signs & symptoms fever, myalgia, arthralgia signs of ischemia

3. Pathogenesis Direct infection: Bacterial Rocky Mountain Spotted fever Syphilis Fungal : aspergillosis, mucormycosis Viral: herpes zoster- varicella

4. Immunologic Immune complex mediated Antineutrophil cytoplasmic antibody (ANCA) mediated Cell mediated Direct antibody mediated Idiopathic

5. Classification Large vessel vasculitis Giant cell arteritis Takayasu arteritis Medium sized vessel vasculitis Polyarteritis nodosa Kawasaki disease Small vessel vasculitis Wegener granulomatosis Churg- stauss syndrome Microscopic polyangitis

6. Giant cell (temporal) arteritis Most common systemic arteritis Acute, chronic granulomatous lesion Large arteries Aorta & its branches Temporal artery Vertebral artery Ophthalmic artery

7. Segmental involvement Nodular thickening & narrow lumen Granulomatous inflammation Giant cells (foreign body & Langhans) Lymphocytes Fragmentation of internal elastic lamina Later fibrosis

8. C/F Always > 50 yrs Increased ESR Pain & tenderness, nodular temporal A Black outs, permanent visual loss Biopsy is confirmatory Anti-inflammatory drugs are effective

9. Takayasu arteritis Granulomatous inflammation Characterised by Ocular disturbances Weakening of pulses in the upper extremities pulseless disease Fibrous thickening of arch of aorta & branches Associated with HLA A24-B52-DR2

10. Arch of aorta & its branches Pulmonary artery Coronary & renal arteries Morphology similar to giant cell arteritis with necrosis Younger age group

11. C/F Lower BP & weak pulses in upper limbs Total blindness HTN Claudication

12. Polyarteritis nodosa (PAN) Small & medium sized muscular arteries Most commonly visceral & renal arteries involved Arterioles, capillaries & venules are not involved Segmental transmural necrotising inflammation Neutrophils Eosinophils Mononuclear cells Fibrinoid necrosis

13. C/F Fever Myalgia Weight loss HTN 30% are associated with hepatitis B Renal involvement is seen No glomerulonephritis

14. Kawasaki disease Young children (<4yrs) & infants Coronary arteries are involved Associated with mucocutaneous lymph node syndrome Fever Conjunctival & oral erythema Skin rashes Cervical lymphadenopathy PAN like inflammation

15. Coronary vasculitis Coronary aneurysms Rupture / thrombosis MI, sudden death

16. Wegener granulomatosis Classic type Triad Acute necrotising granulomas of upper respiratory tract Granulomatous vasculitis of lung & upper respiratory tract Focal necrotising crescentic glomerulonephritis Limited type : restricted to respiratory tract

17. Pathogenesis Immune complex mediated Cell mediated C/F M >F 4 th – 5 th decade c-ANCA + in 95 % of cases

18. Thromboangitis obliterans / Buerger disease Characterised by Segmental thrombosing acute & chronic inflammation of medium sized & small arteries : tibial/ radial a Extending to veins & nerves of extremities

19. Begins < 35yrs Strongly associated with smoking Hypersensitivity to intradermally tobacco extract Associated with HLA-A9, HLA-B5 Prevalent in Israel, Japan, India than US & Europe

20. Segmental acute & chronic vasculitis Lower & upper extremities Thrombosis – recanalisation Contiguous involvement of veins & nerves C/F Gangrene Chronic ulcerations Severe pain: resting pain : nerve involvement

21. Raynaud phenomenon : Paroxysmal pallor, cyanosis of digits of hands or feet and tips of nose & ear Due to cold induced vasoconstriction precapillary arterioles & digital arteries Long standing cases associated with atrophy of skin, subcutaneous tissue & muscle

22. Primary Exaggeration of normal central and local vasomotor response to cold & emotion 3-5% of population Median age-14yrs No arterial pathology Secondary Associated with SLE, systemic sclerosis, atherosclerosis, Buerger disease > 30 yrs + vascular pathology

23. Tumors of vessels Benign neoplasms/ developmental /acquired conditions Hemangioma Capillary Cavernous Pyogenic Lymphangioma Vascular ectasia Bacillary angiomatosis Intermediate grade neoplasms Kaposi sarcoma Hemangioendothelioma Malignant neoplasm Angiosarcoma Hemangiopericytoma

24. Kaposi sarcoma Low grade malignancy Locally aggressive Variants Classic/ European type Lymphadenopathic / African/ endemic Immunosuppression associated AIDS associated type

25. Classic/ European type Eastern Europe Not associated with HIV But homosexuals are at risk Localised to skin

26. Lymphadenopathic / African/ endemic Bantu families Localised / generalised lymphadenopathy Sparse skin lesions Seen in both HIV +/ - Extremely aggressive

27. Immunosuppression associated Transplant associated LN + mucosa + visceral organs Skin lesions are absent

28. AIDS associated Seen in 1/3 rd of AIDS pts Male homosexuals LN + mucosa + skin + viscera Early widespread dissemination

29. Gross Patch Plaque Nodular lesions Microscopy Dilated irregular, angulated blood vessels lined by endothelial cells Spindled cells containing pink hyaline globules Hemosiderin laden macrophages Mitotic figures

30. KS associated Herpes virus (KSHV) / HHV-8 Inhibits apoptosis Increases production of p53 inhibitors Rx : excision + radiotherapy + chemotherapy