How common is itp in adults

i been diagnosed with itp since 2010. My counts flux between 110-120 and have gone down to 69 and as high as 140. I was wondering since everything i read is that this is more common in kids how common is it in adults? could i have i been misdiagnosed even though they ran all tests except bone marrow biopsy and all were negative.

Even though it's considered to be rare, I think it's fairly common. I've seen literally thousands of people here over the years. I've had it and my sister had it.

Your counts have been pretty good overall. Seems like you have mild ITP, no treatment needed which is great! I wouldn't worry about a misdiagnosis. If something else were going on you'd surely know it by now by having physical symptoms or other abnormal labs.

That's my situation. My counts are good enough that my hematologist doesn't want to see me. And I've been at this long enough that everything else has been ruled out due to a lack of stuff happening that would've happened otherwise.

The PDSA newsletter recently included mention of this research:

A diagnostic approach that may help to discriminate inherited thrombocytopenia from chronic immune thrombocytopenia in adult patients.

Inherited thrombocytopenia (IT) is a heterogeneous group of rare diseases that are often confused with immune thrombocytopenia (ITP). The objective of this study was to supply clinicobiological elements that allow a distinction to be drawn between IT and chronic ITP. We then compared 23 adult patients with IT and 9 patients with chronic ITP. Our study revealed six discriminating criteria: (i) an age of discovery <34 years: positive predictive value (PPV) = 88.2% [63.6; 98.5], (ii) a family history of thrombocytopenia: PPV = 100.0% [82.4; 100.0], (iii) a personal history of bleeding: PPV = 100% [76.8; 100.0], (iv) a mean platelet volume >11 fL: PPV = 93.3% [68.1; 99.8], (v) an excess of giant platelets on blood smear: 100.0% [76.8; 100.0], and (vi) a percentage >44% of platelets with a surface area >4 µm2 in electron microscopy: PPV = 83.3% [58.6; 96.4]. If at least three of these criteria were combined, it was possible to distinguish IT from chronic ITP with 91.3% [72.0; 98.9] sensitivity and PPV = 100.0% [66.4; 100.0] specificity. The secondary objective of this study was to assess the prevalence of potential IT diagnosis in patients with chronic thrombocytopenia of uncertain origin. Applying our diagnostic approach to a series of 20 cases allowed us to estimate that 40% of them could be suffering from IT. Finally, our diagnostic approach may help to correctly distinguish IT from chronic ITP, particularly in the context of macrothrombocytopenia.

PMID: 27025585

This indicated to me that there's ongoing work to determine exactly what ITP is and come up with better diagnostic methods to distinguish it from other conditions.

AOI,

A new study published last Friday uses mean platelet volume (MPV), platelet distribution width (PDW), and large cell ratio (P-LCR) to distinguish between hypoproductive thrombcytopenia and ITP (in other words, production versus destruction). They got pretty strong correlations.

bmchematol.biomedcentral.com/articles/10.1186/s12878-016-0057-5
Diagnostic predictive value of platelet indices for discriminating hypo productive versus immune thrombocytopenia purpura in patients attending a tertiary care teaching hospital in Addis Ababa, Ethiopia
Conclusion
MPV, PDW and P-LCR help in predicting thrombocytopenic patients as having ITP or hypoproductive thrombocytopenia. If these indices are used in line with other laboratory and clinical information, they may help in delaying/ avoiding unnecessary bone marrow aspiration in ITP patients or supplement a request for bone morrow aspiration or biopsy in hypoproductive thrombocytopenic patients.

Thanks, Rob16. Very interesting read. I enjoyed the idea of using a statistical model to assess people, and hope that further research is done on the idea. There are a lot of tricky spots to their method, as they acknowledge in the latter part of the article, so I'm curious to see how that will all be sorted out. I'm also interested to see if their method is robust enough to distinguish ITP versus hypoproductive thrombocytopenia reliably, given that the authors state in the conclusion that cutoffs still need to be established.