An Interesting Autopsy case Report of Acute Respiratory Failure

INTRODUCTION

Vasculitis is a group of rare but potentially serious disorders characterized by inflammation of blood vessels. This condition can affect blood vessels of all sizes, ranging from small capillaries to larger arteries. The inflammation can disrupt blood flow, leading to a variety of symptoms and potential complications(1). Vasculitis can target various organs and body systems, making it a challenging condition to diagnose and manage. It is a rare autoimmune disorder with female preponderance causing the immune system to attack blood vessels. Its incidence is 6 in every 1,00000 population and more commonly seen in elderly population. Amongst vasculitis, ANCA associated vasculitis is extremely 100%. The 5 and 10 year survival rates vary from 46% to 85% and 60% to 80% respectively. The mortality rates are falling because of better and advanced treatment options but remain elevated in severe cases. ANCA associated small vessel vasculitis includes microscopic polyangiitis, Wegeners granulomatosis, Churg-strauss syndrome and drug induced vasculitis. The exact cause of vasculitis is often unknown, but it is believed to involve an abnormal immune response. The immune system mistakenly attacks healthy blood vessels, leading to inflammation. Some cases of vasculitis are linked to autoimmune disorders, where the body's immune system attacks its tissues. (3)Other possible triggers include infections, certain medications, and exposure to toxins. The affected individual presents with fatigue, muscle pain, fever, cough, hemoptysis , abdominal pain, blood in urine or weakness and numbness in hands or feet. In severe cases there is presence of blood and protein in urine , making it appear brownish and foamy , high blood pressure and respiratory problem. The normal ANCA level may differ from lab to lab although the normal levels of ELISA are 0.00 to 0.22units/ml. Clinical profile A 29 year old serving soldier was admitted with complains of fever, pain abdomen, hemoptysis, bodyache and dark coloured urine since 03 days. On admission patient was tachypneic and hypotensive. Blood investigations revealed decrease hemoglobin and platelet count. pANCA came out to be positive. CT scan was suggestive of bilateral nodular densities and X Ray showed bilateral fluffy opacities. Despite management with oxygenation, iv fluids and iv antibiotics, there was no improvement in his symptoms and his condition further deteriorated. Bronchoscopy revealed diffuse bronchoalveolar hemorrhage. Biochemical evaluation revealed deranged kidney and liver function test. Patient on ventilation developed bradycardia, hypotension and desaturation. On examination blood pressure was not recordable, carotid pulse was not recordable, CPR was started and patient was declared dead at 1215hrs on 30 Oct 2020. Date 30/10/20 pANCA 4.19, Positive Gram Stain Polymorphonuclear cells seen Urine RE/ME Proteinuria On further investigations, Serum electrolytes, serum protein and C-reactive protein levels were within normal limits. Blood culture, BAL culture, Dengue serology, HbsAg, HIV, COVID-19 Antigen & antibodies, Gene expert for MTB, Antibodies against GBM/ds-DNA/IgM Leptospira/ANA/Factor Hep2 showed negative results.

Patient was taken for autopsy and on external/ gross examination of organs, there was visible hepatomegaly, kidney showed multiple petechial hemorrhages and both lungs were boggy.

Histopathology showed evidence of diffuse alveolar hemorrhages in both lungs. Evidence of vasculitis was noted in small vessels of kidney and lungs, with neutrophilic inflammatory infiltrate around these vessels. Hence it was concluded that p-ANCA associated vasculitis lead to diffuse alveolar hemorrhage, causing acute respiratory distress and eventually respiratory failure.

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The exact cause of vasculitis is often unknown, but it is believed to involve an abnormal immune response. The immune system mistakenly attacks healthy blood vessels, leading to inflammation. Some cases of vasculitis are linked to autoimmune disorders, where the body's immune system attacks its tissues(5). Other possible triggers include infections, certain medications, and exposure to toxins.T he affected individual presents with fatigue, muscle pain, fever, making it appear brownish and foamy , high blood pressure and respiratory problem. The normal ANCA level may differ from lab to lab although the normal levels of ELISA are 0.00 to 0.22units/ml(6).

Vasculitis is a rare autoimmune disorder and hence its diagnosis is extremely challenging. There is no clinical criteria to diagnose a case of vasculitis. The only gold standard investigation in a case of vasculitis is histopathology. Early diagnosis and medical intervention is extremely important to improve long term survival. Hence, any case of vasculitis should be approached in following manner as mentioned in below table:

1. Gloor AD, Berry GJ, Goronzy JJ, Weyand CM. Age as a risk factor in vasculitis. Semin Immunopathol. 2022 May;44(3):281–301. 2. Watts RA, Hatemi G, Burns JC, Mohammad AJ. Global epidemiology of vasculitis. Nat Rev Rheumatol. 2022 Jan;18(1):22–34. 3. Gross WL, Schmitt WH, Csernok E. ANCA and associated diseases: immunodiagnostic and pathogenetic aspects. Clin Exp Immunol. 2008 Jun 28;91(1):1–12. 4. Beaudreuil S, Lasfargues G, Lauériere L, Ghoul ZE, Fourquet F, Longuet C, et al. Occupational exposure in ANCA-positive patients: A case-control study. Kidney Int. 2005 May;67(5):1961–6. 5. Suresh E. Diagnostic approach to patients with suspected vasculitis. Postgrad Med J. 2006 Aug 1;82(970):483–8. 6. Qasim A, Patel JB. ANCA Positive Vasculitis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Sep 17]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK554372/

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