CML Glossary ‘R’
*RBC = red blood cells
RA = Rheumatoid Arthritis
*RAS Oncogene = a mutated version of a gene on chromosome 17 that has been shown to be involved in more than half of all human cancers. It works its mischief by inhibiting apoptosis, or normal programmed cell death.
RBCs = Blood Cells or Red blood cell count
RDW = Red cell distribution width (variation in red blood cell size; a high RDW is associated with a number of conditions including alcoholism and a disturbed bone marrow)
*Remission = abatement or lessening in severity of the symptoms, signs and laboratory abnormalities of a disease. A not-very-specific term, especially as applied to CML. The term “response” is often preferred. Hematologic remission
(response) means that the white cells in your blood are back within the normal range. HR says nothing about the proportion of phillies to normal cells. A cytogenetic remission (CR) means that you’re getting some normal cells back. There are 3 levels of cytogenetic response: just plain cytogenetic response (CR); Major cytogenetic response (MCR); and complete cytogenetic response (CCR). A CR means a Ph+ less than you began with but more than 35%; major response means between 0% and 35% Phillies; and complete cytogenetic response means zero Phillies as measured by either conventional cytogentics or FISH.
Conventional cytogenetics looks at only 20-25 cells, whereas FISH looks at 400 to 500 cells, so FISH is theoretically more accurate. However, some labs have a problem with false positives with FISH, that is, they can read a cell as a Philly when it’s really not. FISH can be done on blood or bone marrow, while conventional cyto can be done only from bone marrow only.
*Molecular response (remission) (MR) = Using the conventional qualitative PCR test, there’s only one level of molecular response, that is, you either have it or you don’t. This test is very sensitive, so if you’re told you have a MR, it means you have less than 1 in 1,000,000 leukemic cells left in your marrow. Quantitative PCR can give an estimate of how many cells are left, but is not quite as sensitive; it can detect down to about one in 100,000 cells.
RN = registered nurse
Rx = prescription