18th February 2024

A 36-year-old male presents to the acute medical unit with haemoptysis

A 36-year-old male presents to the acute medical unit with haemoptysis. He describes feeling malaise for two weeks before developing frank haematuria seven days ago. He had taken antibiotics for this but had not resolved the haematuria. He later developed haemoptysis and shortness of breath two days ago, prompting his admission. Urinalysis reveals proteinuria and haematuria. Blood tests show an acute kidney injury (AKI). Serum p-ANCA and c-ANCA levels were negative with positive anti-GBM antibodies.

Given the likely diagnosis in this case, which of the following hypersensitivity reactions is responsible for the pathogenesis of this condition?

Select the SINGLE most appropriate option from the list below. Select ONE option only.