Blood Disorders

Thrombocytopenia and Other Platelet Disorders

An Overview of Platelet Disorders

Platelet disorders relate to one of the three types of blood cells—platelets, which help repair damaged blood vessels and stop bleeding. Platelets are produced in the bone marrow along with white blood cells, which help fight infections, and red blood cells, which carry oxygen to tissues. 

Platelet disorders can be placed in two large categories: those related to platelet number (​the normal range for platelets is 150,000 cells to 450,000 cells per microliter) and those related to platelet function.

Thrombocytopenia, which results in a lower-than-normal platelet number, can develop if the bone marrow is unable to produce the normal number of platelets or if the platelets are destroyed after they are made. 

Thrombocytosis, which results in a higher-than-normal platelet count, can be a reaction to another medical problem or because the bone marrow is producing too many cells. Platelet function disorders vary greatly in severity and can have normal platelet counts or thrombocytopenia depending on the type.

 

Normal platelet numbers are not affected by age or gender like red blood cells or hemoglobin.  

Common Types of Platelet Disorders

  • Essential thrombocythemia is a myeloproliferative disorder where the bone marrow produces too many platelets, increasing the risk of developing blood clots. 
  • Immune thrombocytopenia is a disorder where the body makes antibodies to its own platelets. The body incorrectly attacks and destroys platelets, often resulting in severe thrombocytopenia with and without bleeding. In children, this is often a transient process, but it is usually a chronic condition in adults. 
  • MYH9-related disorders are a group of platelet function disorders. These disorders are inherited (passed down in families) and may be associated with hearing loss and/or kidney dysfunction.  
  • Neonatal alloimmune thrombocytopenia (NAIT) occurs during pregnancy or shortly after birth. In this form of thrombocytopenia, there is a mismatch between a mother's platelets and those of her developing infant. Antibodies from the mother destroy the infant's platelets, which can cause significant bleeding.  
  • Thrombocytosis (or elevated platelet count) can occur after splenectomy (surgical removal of the spleen), recent infection, or iron deficiency anemia. This is called reactive or secondary thrombocytosis. This is generally transient and improves with treatment of the primary cause. 
  • Congenital megakaryocytic thrombocytopenia (CAMT) is a rare, congenital (meaning you are born with it) disorder where the bone marrow cannot produce platelets normally.   

Symptoms of Platelet Disorders

Symptoms of platelet disorders vary as widely as the diagnoses.

They are dependent on the platelet count and function of the platelets.

Disorders with thrombocytopenia or related to platelet function usually present with bleeding symptoms such as:

  • Nosebleeds
  • Gum bleeding
  • Excessive menstrual bleeding (menorrhagia)
  • Prolonged bleeding after injury or surgery

Disorders with thrombocytosis may not have any obvious symptoms.  Extremely high levels of platelets can result in the development of blood clots (thrombi). Symptoms are related to the development of blood clots.

  • Headaches
  • Vision changes
  • Chest pain

Diagnosing Platelet Disorders

The most common screening test for platelet disorders is a complete blood count (CBC). This simple blood test includes information about all of the blood cells, including the platelet count.

Your physician may request that the platelets be reviewed under the microscope; this is called a blood smear. This will allow your physician to determine whether your platelets are the normal size or not. Several of the inherited platelet function disorders result in platelets that are larger than normal, which can be seen on the blood smear.

Others may be missing key components of the platelets, called granules. 

Platelet function disorders may have a normal number of platelets. These disorders are commonly worked up similar to other bleeding disorders like hemophilia. Screening tests, commonly called coagulation studies, (like prothrombin time, or PT, and partial thromboplastin time, or PTT) are normal. Diagnosing platelet function disorders may require specialty testing such as bleeding time, platelet function assay, platelet aggregation testing, and/or platelet electron microscopy.  

​If there are concerns that your bone marrow is not functioning properly, a bone marrow biopsy may be required as part of the work-up.  

Treatment of Platelet Disorders

Treatment for platelet disorders is also varied and is determined by your specific diagnosis. Some platelet disorders may not require any specific treatment, while others may only require treatment during acute events like bleeding.

  • Platelet transfusions may be used if you have serious bleeding. Platelet transfusions can be used for platelet function disorders (regardless of platelet count) and most platelet disorders with thrombocytopenia. 
  • Steroids like prednisone may be used in immune-related platelet disorders, like ITP.
  • Intravenous immunoglobulin (IVIG) is commonly used in immune-related platelet disorders, like ITP and NAIT.  
  • Aspirin reduces the function of platelets and can be used to prevent blood clots from forming in essential thrombocythemia.  
  • Anti-fibrinolytic medications are medications used to help stabilize clots particularly on the moist surfaces of the mucosa (mouth, nose, uterus, etc.) These medications are commonly used in these conditions for nosebleeds, gum bleeding, and menorrhagia. They can also be used after surgical procedures to prevent bleeding.  

It is important to discuss with your physician what the best treatment is for you and your diagnosis.

A Word From Verywell

Bleeding from a platelet disorder can be startling. Understanding the cause of your bleeding will allow you and your physician to discuss the best treatment options. If your platelet disorder is inherited, this information can also help you determine if other family members should be tested. Try not to let your apprehension get the best of you; discuss your concerns with your physician. Because they can have similar symptoms and treatments, people with platelet disorders may be treated at hemophilia treatment centers.  

Source:

Kaushansky K, Lichtman MA, Prchal J,  Levi MM,  Press O, Burns L, Caligiuri M.  (2016). Williams Hematology (9th ed.) USA. McGraw-Hill Education.

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