Weak correlation of bleeding scores to platelet electron microscopy: A retrospective chart review of pediatric patients with delta‐storage pool disorder

Abstract

Background Delta granule storage pool deficiency (δ‐SPD) is a rare platelet disorder in which a deficiency of platelet granules leads to poor aggregation, resulting in varying clinical bleeding phenotypes. Children with δ‐SPD have variable laboratory results, making the proper diagnosis and evaluation controversial. Objectives To describe the demographic and laboratory trends of this population and to assess the value of electron microscopy in diagnostic evaluation and its correlation to bleeding symptoms. Methods We performed a retrospective review of 109 pediatric patients diagnosed with δ‐SPD. We collected demographic information and bleeding scores using a validated bleeding assessment tool. A descriptive and exploratory analysis was performed. Results The majority of patients were female, with an average age at diagnosis of 11.61 years. Females were diagnosed at a significantly older age presenting most often with menorrhagia, while males presented most commonly with epistaxis. The majority showed normal lumiaggregometry, the mean platelet electron microscopy (PEM) value was 2.37, and the mean bleeding score was 6. Bleeding assessment tool and PEM had a significantly weak correlation. Conclusions Patients with more dense granules per platelet had higher bleeding scores than those with fewer dense granules per platelet. The current body of evidence does not favor the use of PEM in routine clinical practice, and results are difficult to interpret. In patients with severe mucocutaneous bleeding symptoms and normal platelet aggregation studies, consideration should be given to an alternative diagnosis and further evaluation is warranted.

Platelet Aggregation Assays Do Not Reliably Diagnose Platelet Delta Granule Storage Pool Deficiency

“…The BAT has been refined by ISTH working groups and is a valuable screening tool to determine the relative severity of abnormal bleeding, but it is unable to discriminate specific etiologies of unexplained bleeding [ 2 ]. The BAT has a poor correlation to δ-SPD [ 28 ]. Well-defined algorithms have been established to diagnose platelet dysfunction disorders [ 3 , 6 , 29 , 30 ].…”

Platelet Electron Microscopy: Utilizing LEAN Methodology to Optimize Laboratory Workflow

“…We concentrated on determining the number of platelets required to avoid an erroneous result, as a correlation between DB averages and the severity of bleeding symptoms is reportedly absent. 11 We found that utilization of a case-specific algorithm (Figure 4) would eliminate the chance of an incorrect diagnosis while markedly decreasing the number of full 100-platelet counts. The effectiveness of this method is 84%.…”

Circumcision bleeding rates in patients diagnosed with delta‐storage pool deficiency later in life

“…The most frequently ordered tests for platelet function evaluation are light transmission aggregometry and PFA-100 with lumiaggregometry and flow cytometry being less widely used. 9 It has been reported that PFA-100 does not correlate with the presence or severity of δ-SPD and should not be used alone for screening. 16 At our center, we obtain PFA-100 along with PEM as part of the secondary bleeding workup.…”