The phone rang; I vomited. Granted, the ringer for the landline at our apartment blares like a fire engine, demanding attention NOW! I leapt up, relatively speaking, from my easy chair next to a sunny window. I chemo-shuffled at top speed to answer. I absorbed the thirty-second message. Then I reached for my “phucket” bucket, so named because that word is the last to cross my mind just before I retch.
The current fragility of my stomach may be an apt metaphor for the future uncertainty of my immune system. Innocuous encounters, such as a hug or scratching the fur of an unfamiliar pet endanger transplant patients. It may take a year or more for my immune system to mature so that I can live without restrictions on my activities. It is one thing to catch colds over and over. But nasty diseases such as shingles and pneumonia are common threats post transplant. Evidently, after the first year, I must once again receive all my childhood vaccinations. Consequently, for now, I’m to skip around the mud puddles where so much of life’s fun waits to be splashed out.
I’d like to clarify some of the science with respect to the lab numbers we’ve referenced. First of all, let’s define some terms.
Neutrophils are the most common type of white blood cell, comprising about 60-70% of all white blood cells. They can ingest other cells although they do not survive the act. Neutrophils are the first immune cells to arrive at the site of infection.
Though neutrophils are short lived, with a half-life of four to ten hours when not activated and immediate death upon ingesting a pathogen, they are plentiful and responsible for the bulk of an immune response. They are present in the bloodstream until called to a site of infection by chemical cues in the body. They are fast acting, arriving at the right spot within an hour.
Neutrophils carry with them intriguing weapons for the killing they must do. I won’t go into that here, but when they ingest microbes, they release a number of proteins that assist with the fight. To measure for specific proteins and to screen for certain diseases such as MM, a lab test, Serum Protein Electrophoresis, is used.
Monoclonal protein, also known as M-protein or M-spike, is an antibody found in unusually large amounts in the blood or urine of people with MM.
An antibody is a blood protein produced in response to and counteracting a specific antigen. Antibodies combine chemically with substances that the body recognizes as alien such as bacteria, viruses, and foreign substances in the blood.
An antigen is a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.
So, when we say my M-spike trends downward, as it does, the measurement determining that is the quantified presence of unique antibodies present to respond to antigens. In essence, you measure the mess left behind by an immune response or the difference between healthy antibodies and ineffective ones that are cancerous.
For your convenience, Marilyn created a graph to show my response to various treatments since January. At that time my M-protein was as high as 4.5 g/dl. The most recent test has that marker down to 0.3 g/dl. That’s good. The goal, however, is zero. Otherwise, I continue treatment. And, the date for determining the success of the transplant in achieving that goal is 80-90 days from when I received the stem cells. We are at Day + 16 and counting.
One more thing, clinical engraftment occurs when a transplant patient achieves two consecutive days of neutrophils above 500. That happened yesterday.
I hope this helps you understand why we keep talking about monoclonal proteins and neutrophils. They are big players in the staging of multiple myeloma.