- Abnormal FLC ratio and absence of end organ damage (CRAB) defined as: lytic bone lesions on skeletal survey, calcium ≥ 11mg/dl, hemoglobin value of >2 g/100 ml below the lower limit of normal or a hemoglobin value <10 g/100 ml and renal insufficiency(serum creatinine >0.173 mmol/l) Note: Patients with BMPC > 60%, serum free light chain ratio >100, or known to have 2 or greater focal lesions on MRI and are clinically felt to require therapy will not be included.