CRAB criteria are vital for diagnosing myeloma: 'C' denotes increased blood calcium, 'R' signifies kidney damage, 'A' indicates anemia, and 'B' represents bone damage. Early myeloma features include high bone marrow plasma cells, an elevated free light ratio, or multiple bone lesions."
Pre-CRAB identifies patients before CRAB features have developed but who show specific criteria indicating progression within 12-18 months. Early treatment based on CRAB and pre-CRAB criteria leads to better outcomes. The IMF is conducting trials that are trying to achieve long-term cure by starting treatment in the early disease setting.
The BOTTOM LINE: Early recognition and treatment guided by CRAB and pre-CRAB criteria are crucial for improved outcomes and potential long-term remission in myeloma patients.
Please note that Ask Dr. Durie has been discontinued, and it was designed to address myeloma questions of the broadest possible audience interest. If you have a question of a personal nature, please contact our InfoLine Coordinators at 800.452.2873 or [email protected] (Please do not send email attachments or lab reports.).
This week's "Ask Dr. Durie" comes from a patient that wants to know about some common acronyms that we use quite frequently. CRAB and pre-CRAB. What are these terms mean and how important are they? So the CRAB criteria are the criteria that we use to diagnose myeloma. C means calcium level increased in the blood, R means renal or kidney damage with elevated blood creatinine, A means anemia, and B means bone damage showing up on x ray or scan. So if you have any one or more of the CRAB criteria, this is a key feature of active myeloma, and we use that as a basis to consider starting treatment for prescribed criteria. These are earlier features that give an indication that myeloma is about to become fully active.
And these are criteria in two groups. One, early features of myeloma, which include, the fact that the bone marrow plasma cells are 60% or higher, that the free light ratio is 100 or higher, or that the X-rays or scans show more than one lesion in the bones. If you have any one of those, then you fall into this prescribed category.
Another category, very similar is patients with high risk smoldering or ultra high-risk smoldering myeloma where we use different criteria to indicate that they are also likely to develop myeloma soon, within 12-to-18 months. These criteria are called the 20/2/20 related to the size of the spike, the free line ratio and the percentage of plasma cells in the bone marrow or if there's evidence of change over a six month period.
And so, these CRAB and pre-CRAB criteria are both very, very important in decision making, related to treatment.
The BOTTOM LINE is, with CRAB criteria, you definitely need to be looking closely at starting treatment. Pre-CRAB criteria, these are situations where you need to talk to your doctor and make sure what is the situation.
But most likely treatment would also be recommended and in the setting of expecting to achieve really excellent results. When you start treatment earlier, the outcomes are likely to be better. You're likely to get a deeper response and probably a longer response. And we have been conducting trials where we were actually trying to achieve long term cure, starting treatment and these earlier disease setting. So, pre-CRAB; CRAB, are both very, very important in treatment decision making.
Dr. Brian G.M. Durie (1942-2025) was the co-founder of the IMF. He was a Professor of Medicine, Hematologist/Oncologist, and Honoree MD at the University of Brussels.
