Thrombocytopenia occurs when your blood platelet levels are too low. Doctors use a grading system to determine the severity of your thrombocytopenia and its treatment.

Thrombocytopenia is when the levels of platelets (also called thrombocytes) in your blood are too low. Platelets are tiny blood cells that help your blood to clot.

When you have thrombocytopenia, you can have trouble stopping bleeding when it occurs. You may also experience bleeding under your skin. If platelet levels get very low, it can lead to potentially serious or life threatening internal bleeding.

In some situations, doctors may grade thrombocytopenia to assess its severity or the bleeding associated with it.

This article takes a closer look at the grading criteria for both chemotherapy-induced thrombocytopenia and immune thrombocytopenia.

What are the primary types of thrombocytopenia?

Immune thrombocytopenia (ITP): ITP is the most common type of thrombocytopenia and is usually caused by problems with your immune system. ITP can be acute (lasting less than 6 months) or chronic (lasting more than 6 months).

Chemotherapy-induced thrombocytopenia (CIT): CIT often occurs in people with cancer. It may be due to the cancer itself or from chemotherapy treatment.

Was this helpful?

Immune thrombocytopenia (ITP) is a condition in which your immune system mistakenly attacks platelets. This leads to a reduced platelet count.

The development of ITP is associated with certain drugs, infections, and some preexisting autoimmune conditions. ITP can impact people of all ages. An estimated 40% of those diagnosed with ITP are children under the age of 10.

Grades and treatment of immune thrombocytopenia

While platelet count is an important part of the diagnosis of ITP, grading often involves evaluating the severity of the bleeding. There are several grading systems for bleeding that may be used.

One of these is the Buchanan and Adix bleeding score. The table below shows the different grades of this system.

Grade 0no bleeding observed
Grade 1minor skin bleeding, such as five or fewer small bruises and/or 100 or fewer petechiae
Grade 2more significant skin bleeding, such as more than five large bruises and/or over 100 petechiae
Grade 3signs of mucosal bleeding, such as blood crusting in nostrils or nosebleed, petechiae or purpura in the mouth, blood in the urine or stool, and heavy periods
Grade 4more severe mucosal bleeding or suspected internal bleeding, such as in the brain or lungs that requires immediate medical attention
Grade 5confirmed brain bleed or other life threatening or fatal bleeding

Higher grades are associated with more severe disease. A 2022 review notes that grades 4 and 5, and sometimes grade 3 bleeding, require prompt medical intervention.

The treatment of ITP depends on many factors, including but not limited to the grade of the bleeding, how low platelet levels are, and the age of the person with ITP. Some potential treatment options can include one or a combination of:

Chemotherapy is a cancer treatment that uses drugs that interfere with the growth and division of cancer cells. Chemo drugs can also affect areas of the body where healthy cells are growing and dividing, such as the bone marrow.

Platelets are made in the bone marrow. Because of this, the effects of chemo can reduce the number of platelets that are made. This is called chemotherapy-induced thrombocytopenia (CIT).

A 2021 study found that 13% of participants with solid cancers and 28% of participants with blood cancers had CIT after 3 months of chemo. Those who received chemo with gemcitabine or platinum-based regimens had a higher incidence of CIT.

Grades and treatment of chemotherapy-induced thrombocytopenia

CIT is graded based on how low your platelet levels are. Platelet levels can be measured using a blood test called a complete blood count. The table below shows the different grades of CIT.

GradePlatelets per liter (L) of blood
Grade 175×109 to less than 100×109
Grade 250×109 to less than 75×109
Grade 325×109 to less than 50×109
Grade 4less than 25×109

Higher grades indicate more severe CIT. A 2023 review notes that milder (lower grade) CIT doesn’t have any immediate clinical effects. However, the 2021 study above notes that low-grade CIT may signal a higher risk of severe CIT later on.

Higher grades (grades 3 and 4) are considered severe and need to be addressed. Severe CIT may be managed by:

  • reducing the dose or frequency of the chemo
  • switching to a different chemo regimen
  • platelet transfusions
  • drugs that promote platelet production

Thrombocytopenia happens when your platelet counts get too low. In some situations, such as CIT and ITP, a grading system may be used to assess the severity of the thrombocytopenia or the bleeding associated with it.

Generally speaking, lower-grade thrombocytopenia may not require immediate intervention. However, severe thrombocytopenia needs to be addressed promptly in order to help prevent potentially life threatening complications.