CD40LG and retinal disorder: However, 2.5 years later, the patient developed retinopathy due to hyperviscosity, a rapidly elevated IgM level (5,534 mg/dL, reference range: 33-190 mg/dL), and thrombocytopenia (platelet count: 24,000/μL, reference range: 15.8-34.8 × 104/μL).