Figure 5.

Detection of the alternative pathway component CFD in lung and kidney samples from patients with COVID-19. Overview of immunohistochemical staining for complement factor D (CFD) in lung samples of a control patient (A) and a patient with COVID-19 (B) was shown. Results of semi-quantitative scoring in multiple compartments for CFD deposition in the lung were summarized in a sum score (C) and overview of the mean values of compartment-specific analyses is given in a heat map (D). Representative CFD stainings in alveolar septa of a control patient (E) and a COVID-19 patient (F) and comparative analyses are shown (G). CFD staining in alveolar lumina in a control patient (H) and a patient with COVID-19 (I) and statistical comparison of both groups (J). Overview of CFD staining in kidney samples of a control patient (K) and a patient with COVID-19 (L). Results of semi-quantitative scoring in multiple compartments for CFD deposition in the kidney are summarized in a sum score (M) and overview of the mean values of compartment-specific analyses is given in a heat map (N). Representative CFD staining in peritubular capillaries of a control patient (O) and a COVID-19 patient (P, arrows) and a comparative analyses (Q). CFD staining of tubular basement membrane in a control patient (R) and a patient with COVID-19 (S, arrows) and comparison of both groups (T). AS, alveolar septa; A inf, accumulation of alveolar inflammatory cells; A lumen, alveolar lumen; Bro, bronchioles; Vasc, vascular; sign., significance; ns, non-significant; PTC, peritubular capillaries; Art, arterial; Glom, glomerular; TBM, tubular basement membrane; BM, basement membrane. Scale bar = 200µm; *p < 0.05; **p < 0.01; ****p < 0.0001.