Monitoring of free eculizumab levels and CH50 in 2 representative cases. (A) Overweight patient. (B) Aplastic PNH syndrome. For each panel, hemoglobin (red filled circles), CH50 (black filled square with dash line), LDH (blue filled triangle), and free eculizumab (black filled squares with solid line) levels are shown. A gray dash line indicates blocked CH50 (≤10%), whereas a blue dash line represents the normal value for LDH (upper limit, 480 UI/L). Red asterisks represent red blood cell transfusion episodes during follow-up. Treatment and eculizumab doses during follow-up are indicated.