Does COVID-19 cause an increase in spleen dimensions? Possible effects of immune activation, hematopoietic suppression and microthrombosis.

Purpose: To radiologically examine how the spleen size, which has important functions in hematological and immunological balance, is affected in COVID-19.

Methods: Between July 1 and August 31, 2020, consecutive patients diagnosed with COVID-19 were analyzed. Among these patients, those who underwent chest computed tomography (CT) examination at the time of presentation, patients with follow-up CT due to clinical deterioration were included in the study. The CTs of the patients were evaluated in terms of spleen size and volume.

Results: A total of 160 patients (88 females, 55%) were included in the study. The mean time between the initial and follow-up CT was 7.2 ± 2.8 days. The splenic volume (244.3 ± 136.7 vs. 303.5 ± 156.3 cm) and splenic index (421.2 ± 235.5 vs. 523.2 ± 269.4 cm) values were significantly higher in the follow-up CT compared to the initial CT (p < 0.001). The increase in the splenic volume and splenic index values was 59.2 ± 52.4 cm and 101.9 ± 90.3 cm (p < 0.001), respectively. The COVID-19 severity score was significantly higher in the follow-up CT compared to the initial CT (3.7 ± 4.2 vs. 12.5 ± 5.7, respectively; p < 0.001). The spleen width measured separately on the initial and follow-up CTs showed a highest positive correlation (r = 0.982, p < 0.001).

Conclusion: Our study indicates that spleen size increases slightly-moderately in the first stages of the infection, and this increase is correlated with the COVID-19 severity score calculated on the chest CT data, and in this respect, it is similar to infections presenting with cytokine storm.