Respiratory changes in a murine model of spontaneous systemic lupus erythematosus

The pathophysiology of systemic lupus erythematosus (SLE) has been very well described in many organs. However, the relation between extracellular matrix changes and lung dynamic mechanical behaviour deserves elucidation. To that end, pulmonary mechanics, lung morphometry and the amount of collagen and elastic fibres in the alveolar septa were analysed in mice with SLE [NZB/W (New Zealand Black/White) F1] and non-diseased NZW mice (control). Static (Est) and dynamic (Edyn) elastances, difference between dynamic and static elastances (ΔE), airway resistance (Raw) and viscoelastic/inhomogeneous pressure (ΔP2) were determined by the end-inflation occlusion method. Lungs were removed and prepared for histology. Est, Edyn, ΔE and ΔP2 were higher in SLE than in control group, while Raw was similar in both groups. SLE group showed alveolar collapse and increased amount of elastic and collagen fibres. In conclusion, SLE mice showed an increase in elastic and viscoelastic/inhomogeneous pressures that was accompanied by deposition of collagen and elastic fibres in the alveolar septa.