ACE and influenza: A systemic laboratory workup, including complete blood count, serum biochemistry, and serologic and immunologic tests for syphilis, tuberculosis, influenza, varicella, toxoplasmosis, toxocariasis, human immunodeficiency virus (HIV), cytomegalovirus (CMV), anti-aquaporin 4 Ab, angiotensin converting enzyme (ACE), anti-nuclear antibody (ANA)&anti-neutrophil cytoplasmic antibody (ANCA), rheumatoid factor (RF), and anti-CCP, was performed to rule out underlying conditions that may cause infectious and inflammatory disorders.