TNF and lymphopenia: Interstitial pneumonia and lymphopenia, driven by high levels of pro-inflammatory cytokines including interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), C-X-C ligand 10 (CXCL10), C-C motif ligand 2 (CCL2) and CCL3, may be seen in severe cases.