Immature platelet fraction values predict recovery of platelet counts following liver transplantation

Immature platelets: a review of the available evidence

Immature platelets or reticulated platelets are newly released thrombocytes. They can be identified by their large size and high RNA cytoplasm concentration. Immature platelet fraction (IPF) represents the percentage of immature circulative platelets to the total number of platelets. The development of analytical standardization of this hematological parameter by new automated devices allowed a better exploration of its contribution in a context of thrombocytopenia. In fact, several studies had confirmed its clinical utility to differentiate immune thrombocytopenia from other causes of thrombocytopenia. IPF can also predict platelets recovery after chemotherapy and successful engraftment. In addition, immature platelets have shown utility in other diseases such as coronary artery diseases, bacterial infections and liver diseases. Despite all these advantages, immature platelet fraction can be increased in some cases of thrombocytopenia characterized by platelets hypoproduction. The aim of this review is to present the immature platelet fraction contribution in clinical practice.

Immature platelet fraction and thrombopoietin in patients with liver cirrhosis: A cohort study

BACKGROUND AND AIMS

Thrombocytopenia occurs frequently in patients with cirrhosis. The immature platelet fraction (IPF%) is measured to differentiate the causes of thrombocytopenia. To date the relevance of thrombopoietin (TPO) in the context of cirrhosis is unknown. The aim of our study was to investigate the cause of thrombocytopenia in patients with liver cirrhosis by measuring IPF%, TPO and spleen size. In addition we examined the use of IPF% to evaluate the severity of cirrhosis and its complications.

METHODS

Overall, we included 88 in-patients with cirrhosis in our study. The collected data comprises current health status, blood parameters, severity of cirrhosis evaluated by Child-Pugh score and MELD score, spleen diameter, ascites and esophageal varices. The IPF% was measured using an automatic hematology analyzer. TPO was measured with ELISA.

RESULTS

IPF% (p = 0.003) and spleen diameter (p = 0.001) were significantly higher in patients with thrombocytopenia. There was no significant difference in TPO between patients with and without thrombocytopenia. The mean values of IPF% varied significantly (p = 0.044) in Child-Pugh stages. IPF% was significantly (p = 0.005) elevated in patients with esophageal varices. Moreover, IPF% higher than 3.85% displayed sensitivity of 76.6% and specificity of 52.4% with an area under receiver operating curve characteristics of 0.669 for the presence of esophageal varices.

CONCLUSION

On closer examination of the three compartments known to have an influence on platelet count splenomegaly seems to be the major cause of thrombocytopenia in patients with cirrhosis according to current knowledge. Higher IPF% in patients with thrombocytopenia indicates peripheral consumption of platelets. The relation between spleen diameter and platelet count indicates the spleen to be the major place of platelets' consumption. TPO did not differ between patients with and without thrombocytopenia. Furthermore, we cannot exclude an influence of impaired thrombopoietin synthesis on platelet counts. The association between IPF% and platelet count suggests that there is physiological regulation of platelets in patients with cirrhosis. In our study IPF% is associated with esophageal varices and the stage of cirrhosis. Further studies are needed to confirm these results.

Donors With Immune Thrombocytopenia: Do They Pose a Risk to Transplant Recipients?

Transplant-mediated alloimmune thrombocytopenia (TMAT) from donors with immune thrombocytopenia (ITP) can result in significant bleeding complications in the recipient. The risk to a recipient of TMAT if they receive an organ from a donor with ITP is unknown. The outcomes of recipients of organs from deceased donors with ITP recorded in the UK Transplant Registry between 2000 and 2015 were reviewed. Twenty-one deceased organ donors had a predonation diagnosis of ITP. These donors were significantly more likely to have died from intracranial hemorrhage than were all other deceased organ donors (85% vs. 57%, p < 0.001). Organs from donors with ITP resulted in 49 organ transplants (31 kidney, 14 liver, four heart), with only one case of TMAT, which occurred in a liver transplant recipient and resulted in death from bleeding complications 18 days posttransplantation. The recipient of a kidney from the same organ donor was not affected. Unadjusted 5-year patient and graft survival was significantly worse for liver transplant recipients from donors with ITP compared with liver transplant recipients from donors without ITP (64% vs. 85%, p = 0.012). Organs from donors with ITP may be considered for transplantation, but livers should be used with caution.