Teaching Case

A 24-year-old man was admitted with a history of fever, cough and recurrent haemoptysis for 1 month and breathlessness for 5 days. His investigations revealed anaemia with normal bleeding parameters. Urine showed proteinuria and haematuria. Antibodies to glomerular basement membrane (Anti GBM- Abs) were positive.

A series of chest radiographs taken over a period of 4 days showed bilateral areas of consolidation more pronounced on the right side (Figure 1). CT of the chest done at the time of admission showed extensive bilateral symmetrical areas of ground glass attenuation with smooth septal thickening resembling crazy paving pattern involving bilateral lungs (Figure 3, 4, 5). Possibility of pulmonary haemorrhage syndrome - Goodpasture’s syndrome had to be ruled out.

DAH (diffuse alveolar haemorrhage) can be defined by the presence of haemoptysis, diffuse alveolar infiltrate, and a drop in haematocrit level. Pulmonary-renal syndrome is defined as the combination of DAH and glomerulonephritis. The differential diagnosis includes mainly the ANCA-associated vasculitides, Goodpasture’s syndrome and systemic lupus erythematosus [1].

Goodpasture’s syndrome is a clinical triad of circulating antiglomerular basement membrane antibody, DAH, and glomerulonephritis [2, 3]. This condition is predominantly seen in young men and associated with pulmonary haemorrhage or pulmonary capillaritis. GPS is characterized by the presence of autoantibodies mainly in alveolar and glomerular basement membranes. Genetic and environmental factors are known to worsen the pulmonary lesions [4]. Circulating antibodies are predicative of the severity of the renal and pulmonary injury, as well as immediate and long term prognosis [5].
The pulmonary presentation consists of nonspecific signs and symptoms like cough and haemoptysis which overlap with those of infections, connective tissue diseases and malignancies [6].

Chest radiographs typically show extensive patchy or diffuse bilateral air space opacities. The apex and cost-phrenic angles are usually spared. The consolidation usually resolves in 2-3 days and is replaced by reticulonodular pattern [1, 2, 6]. Bilateral ground glass opacities (GGO) and consolidation are the commonest CT features [6]. The presence of dense consolidation represents complete filling of alveoli with blood. Smooth interlobular septal thickening becomes superimposed on areas of GGO (a crazy paving appearance) within 2–3 days, as haemosiderin-laden macrophages accumulate in the interstitium.

Occasionally ili-defined centrilobular nodules with no zonal predominance may be present reflecting intraalveolar accumulation of pulmonary macrophages [1, 2]. Complete clearing of airspace and interstitial opacities usually occurs within 10 days to 2 weeks if no further haemorrhage occurs. This is considerably slower than clearing of pulmonary oedema. Chronic cases show a persistent reticular pattern with areas of honeycombing and traction bronchiectasis [1].

The diagnosis is confirmed by the presence of anti-basement membrane antibody in the serum or continuous linear deposits of IgG along the basement membranes in renal or lung tissue. In patients without clinical evidence of active renal disease, serum antibodies may be absent and the diagnosis can only be established by demonstrating linear immunofluorescence in lung or renal tissue [7].

Radiologic signs of DAH may be nonspecific and variable but must be considered in patients with otherwise unexplained alveolar infiltrates, particularly when seen with new-onset renal insufficiency or a connective tissue disease to enable earlier diagnosis [1].