My friend who was diagnosed recently with throat cancer said he was hospitalized and isolated due to a very low white blood cell count caused by the radiation and chemotherapy treatments he has been undergoing for the past few weeks. Eight days ago, he had reported that the next day’s chemo treatment had been postponed for a week due to a reduced platelet count.
So, what are these platelets and what do they do? And why would a low white blood cell count require a patient to be quarantined? Inquiring minds – and caring friends – want to know.
First, let’s find out what a low platelet count it and what that means to someone who has it. I’ll follow up soon with a second article about low white blood cell counts.
Platelets are essential for normal blood clotting and plugging damaged blood vessels. Also called thrombocytes (THROM-bo-sites), platelets are colorless blood cells made in the bone marrow. Bone marrow is the soft, spongy tissue located inside larger bones in the body that is a key part of the body’s immune system.
Thrombocytes group together into oversized cells called megakaryocytes (me-ga-CARE-o-sites) in the bone marrow, and are released into the blood to circulate.
It turns out that thrombocytopenia (THROM-bo-SIGH-toe-PEE-nee-ya) – when there aren’t enough platelets to stop bleeding by clumping and forming plugs in blood vessel injuries – is a common condition seen in cancer patients, especially when they receive chemotherapy.
Some types of chemotherapy cause bone marrow damage that lowers platelet production. Only rarely is thrombocytopenia a permanent condition after chemo treatments.
Normal platelet counts range between 150,000 and 450,000 platelets per microliter of circulating blood. The life expectancy of a platelet is 8-10 days so the body continually makes new platelets in the bone marrow to replenish the platelets that have naturally died off.
Thrombocytopenia occurs when:
- The body does not make enough platelets
- The body loses platelets
- The body destroys platelets
When conditions, including pregnancy, bacteria in the blood, and certain medications, cause the body to use up or destroy platelets faster than they can be replaced, a low platelet count is likely.
Because platelets are formed in the bone marrow, low production can lead to thrombocytopenia. Factors that can decrease platelet production include leukemia, some types of anemia, viral infections such as hepatitis C or HIV, chemotherapy drugs, and heavy alcohol consumption.
Sometimes, antibodies go rogue and seek to kill essential team-player platelets, mistaking them for potentially harmful intruders such as bacteria and viruses.
Not only are low platelet counts associated with chemotherapy but also with certain types of cancer. For example, carcinogenic leukemia or lymphoma cells invade the bone marrow where they multiply and crowd out healthy marrow cells.
By itself, radiation therapy by itself normally does not cause thrombocytopenia but may occur when a large amount of radiation therapy is directed at the pelvis or the patient is receiving chemotherapy at the same time.
Symptoms of thrombocytopenia often appear only after the platelet levels become very low and include:
- Unexpected bruising (purpura)
- Superficial bleeding into the skin that appears as a rash of pinpoint-sized reddish-purple spots (petechiae), usually on the lower legs
- Prolonged bleeding
- Bleeding from the nose or gums
- Unusually heavy menstrual flows
- Black or bloody bowel movements
- Red- or pink-colored urine
- Bloody vomit
- Enlarged spleen
- Severe headaches
- Pain in the joints or muscles
- Increased weakness
A sample of blood can be tested in a laboratory to gauge the blood’s platelet count.
Nosebleeds or bleeding cuts that are hard to stop may be a signal to check for thrombocytopenia. Bleeding that won’t stop is a medical emergency. Seek help immediately (dial 911) if you experience bleeding that can’t be controlled by conventional first-aid techniques, notably applying direct pressure to the area.
After a blood cell or tissue is injured such that it bleeds, platelets spring into action as they:
- Adhere to the injury site
- Clump together (aggregate) with other platelets
- Release chemical compounds that stimulate the aggregation of other platelets
Recall that healthy platelet fall between 150,000-450,000 platelets per microliter. If a person’s platelet count falls below 10,000 platelets per microliter of blood, dangerous internal bleeding can occur. This rare condition (severe thrombocytopenia) can cause bleeding into the brain which can be fatal.
Unfortunately, the experts say there are no lifestyle changes to raise a low platelet count. Treatment for this condition typically involves addressing the underlying condition causing it. A mild condition with a slightly-low platelet count may not require any treatment.
The bottom line is that not having enough platelets means the body can’t stop bleeding after it starts, no matter where or how it starts. If normal measures such as pressure fail to stop the bleeding, get help right away before passing out and possibly dying from blood loss.