{"id":10807,"date":"2021-08-31T11:00:04","date_gmt":"2021-08-31T01:00:04","guid":{"rendered":"https:\/\/mvec.mcri.edu.au\/?post_type=references&p=10807"},"modified":"2024-09-10T15:07:07","modified_gmt":"2024-09-10T05:07:07","slug":"mien-dich-giam-tieu-cau-itp","status":"publish","type":"references","link":"https:\/\/mvec.mcri.edu.au\/vi\/references\/immune-thrombocytopenia-itp\/","title":{"rendered":"Gi\u1ea3m ti\u1ec3u c\u1ea7u mi\u1ec5n d\u1ecbch (ITP)"},"content":{"rendered":"
<\/p>\n

L\u00fd l\u1ecbch<\/h2>\n

Immune thrombocytopenia, previously known as idiopathic thrombocytopenia purpura (ITP) and still commonly referred to as ITP, is an uncommon autoimmune condition in which the body\u2019s own immune system attacks platelets (the cells found in the blood which help it clot). The body produces antibodies that attack and destroy platelets; this results in decreased platelet numbers and can cause symptoms such as bruising, petechiae (pin-point red spots on the skin) or bleeding (e.g. nose bleeds or bleeding from the gums). Some people have no symptoms at all.<\/span><\/p>\n

ITP is most often triggered by a viral illness occurring in the weeks prior to ITP symptoms developing. ITP can be acute (lasting less than 12 months) or chronic (lasting longer than 12 months), with acute ITP far more common in children and chronic ITP far more common in adults. The symptoms of acute and chronic ITP are the same. Approximately one in every 10,000 children will be affected by <\/span>ITP<\/span>.<\/span><\/p>\n

It is not uncommon for cases of ITP to be discovered by chance. In some instances, ITP may go away without any treatment. However, when platelets are very low or there are symptoms of bleeding, treatment may be needed. Corticosteroids and intravenous immunoglobulin are the most common forms of initial treatment.<\/span><\/p>\n

ITP and vaccines<\/h2>\n

As ITP is an <\/span>immune-<\/span>mediated <\/span>condition<\/span> (<\/span>a disease <\/span>thought <\/span>\u0110\u1ebeN <\/span>result from an abnormal immune system response<\/span>)<\/span>, it can <\/span>be triggered by<\/span> the body\u2019s immune response to<\/span> vaccination. <\/span>While there are some small studies <\/span>c\u00e1i \u0111\u00f3<\/span> suggest a possible increased risk of ITP with <\/span>certain <\/span>

<\/div> <\/span>(<\/span>such <\/span>as influenza, HPV, <\/span>b\u1ec7nh b\u1ea1i li\u1ec7t<\/span> and pneumococcal vaccines<\/span>),<\/span> ITP has <\/span>only <\/span>been found to be associated with measle<\/span>S<\/span>, <\/span>mumps<\/span> and rubella (MMR)<\/span>-containing<\/span> v\u1eafc xin<\/span>S<\/span> (<\/span>including<\/span> MMRV),<\/span> and COVID-19 vaccines. <\/span>It is important to note that there is a much higher risk of ITP associated <\/span>with infection compared to the risk associated with vaccination.<\/span><\/span>\u00a0<\/span><\/p>\n

ITP and measles-mumps-rubella (MMR) vaccines<\/h3>\n

MMR vaccines have been associated with ITP, with the risk estimated at <\/span>approximately 1<\/span> in 25,000 vaccinations<\/span>.\u00a0 <\/span>C\u00e1c<\/span> risk following <\/span>vaccination is much lower than the risk <\/span>associated<\/span> with natural <\/span>measles or rubella<\/span> infections. <\/span>Therefore, patients with a history of ITP are still recommended to receive<\/span> c\u00e1c<\/span> MMR<\/span> v\u1eafc xin<\/span> in line with <\/span>the National Immunisation Program (NIP), despite the small risk of relapse, to protect ag<\/span>ainst disease.<\/span><\/span><\/p>\n

In children with <\/span>a history of <\/span>either non-<\/span>vaccine or vaccine-associated ITP who have already received their first dose of MMR vaccine, vaccine <\/span>titres<\/span> can be checked<\/span> \u0110\u1ebeN <\/span>determine<\/span> the need for dose 2<\/span>. If the child displays full<\/span> immunity, then no further MMR<\/span>-containing<\/span> v\u1eafc xin<\/span>S<\/span> should be given<\/span> (<\/span>e.g.<\/span> administer varicella alone<\/span> at 18 months<\/span>)<\/span>; if the child does not have adequate immunity, then the child <\/span>n\u00ean<\/span> receive dose 2 as scheduled<\/span>.<\/span><\/span><\/p>\n

V\u1eafc xin ITP v\u00e0 COVID-19<\/h3>\n

New onset or exacerbation of existing ITP ha<\/span>S<\/span> been reported following COVID-1<\/span>9<\/span> ti\u00eam ch\u1ee7ng<\/span>,<\/span> with<\/span><\/span> mRNA vaccines (Comirnaty <\/span><\/span><\/span>(Pfizer) and <\/span><\/span><\/span>Spikevax(<\/span><\/span><\/span>Moderna)<\/span><\/span><\/span>)<\/span><\/span><\/span> and with <\/span><\/span><\/span>Vax<\/span><\/span><\/span>z<\/span><\/span>evria<\/span><\/span><\/span> (<\/span><\/span><\/span>c\u00e1c<\/span><\/span><\/span>\u00a0AstraZen<\/span>eca vaccine which is no longer in use<\/span>)<\/span>. <\/span>This<\/span> li\u00ean k\u1ebft <\/span>continues to <\/span>be investigated;<\/span> h<\/span>owever, th<\/span>e<\/span> risk is low<\/span>.<\/span> Vaccinat<\/span>ion<\/span> l\u00e0<\/span> important to reduce th<\/span>e risk of severe <\/span>COVID-19 <\/span>disease. I<\/span>t<\/span> is important to note that<\/span> ITP can <\/span>also <\/span>be triggered by COVID-19 infection <\/span>itself<\/span>.<\/span><\/span>\u00a0<\/span><\/p>\n

khuy\u1ebfn ngh\u1ecb<\/h2>\n

Individuals who have previously been diagnosed with<\/span> non-vaccine<\/span> or vaccine-associated <\/span>ITP (acute or chronic) are recommended to <\/span>proceed<\/span> with vaccination as per the NIP.<\/span><\/p>\n

There is limited data suggesting that chronic ITP may worsen following vaccination in those with existing chronic ITP (whether non-vaccine or vaccine-associated). Note that the risk of ITP worsening is likely higher if an individual with chronic ITP is infected with a virus than it is following vaccination. If clinical symptoms worsen post-vaccination (days to weeks), then monitoring of platelets and escalation of therapy may be required. <\/span>Signs and symptoms of worsening ITP include:<\/span><\/p>\n