ITP diagnosis

ITP is identified by a diagnosis of exclusion

There is no single blood test that can prove whether a patient has ITP, so it has to be a process of eliminating other possible causes based on a patient’s history, on examinations, and on the results of initial tests. In diagnosing ITP, the healthcare provider will carry out blood tests to identify the underlying causes of low platelets. ITP is diagnosed if blood tests show that only the platelet count is low while the platelets, red blood cells and white blood cells all look normal.

In cases of persistent ITP, a bone marrow biopsy may be recommended to rule out other causes for a reduced platelet count. A small sample of bone marrow is taken under local anaesthetic and examined under the microscope. If the bone marrow is free from abnormalities and other blood tests are normal, then chronic ITP will be diagnosed.
 

What causes ITP?
 

Primary ITP is an autoimmune disease: the immune system mistakes the body’s platelets as being foreign and destroys them.¹ The condition may be triggered by:

• Allergic reaction to medications
• Viral infections
• Pregnancy
• Immune disorders such as rheumatoid arthritis and lupus.

ITP usually develops gradually and often without a clear cause. When the condition lasts more than a year it is called chronic ITP.

ITP can also arise as a result of another illness, in which case it is called secondary ITP. ^1,2

References

1 Immune thrombocytopenia (ITP) World Impact Survey (I-WISh): Impact of ITP on health-related quality of life. Cooper N, Kruse A, Kruse C, Watson S, Morgan M, Provan D, Ghanima W, Arnold DM, Tomiyama Y, Santoro C, Michel M, Laborde S, Lovrencic B, Hou M, Bailey T, Taylor-Stokes G, Haenig J, Bussel JB. Am J Hematol. 2021 Feb 1;96(2):199-207. doi: 10.1002/ajh.26036. Epub 2020 Dec 19. PMID: 33107998

2 Immune Thrombocytopenia (ITP): Current Limitations in Patient Management.Terrell DR, Neunert CE, Cooper N, Heitink-Pollé KM, Kruse C, Imbach P, Kühne T, Ghanima W. Medicina (Kaunas). 2020 Nov 30;56(12):667. doi: 10.3390/medicina56120667. PMID: 33266286