Combined Acquired Alpha- and Delta-Storage Pool Disease in Endstage Renal

Background Bleeding due to platelet dysfunction can result from congenital or acquired defects. The laboratory approach to identify the pathogeneses of acquired platelet dysfunctions is challenging, especially in pediatric patients. A combination of immunofluorescent microscopy (IFM), flow cytometry (FC), and lumino-aggregometry (LA) may help establishing the right diagnosis.

Case Report We report on a 20-month-old boy with end-stage renal failure due to congenital anomalies of kidney and urinary tract. The patient was scheduled for living-kidney transplantation. The family reported that he suffered from several bleeding episodes including bleeding after Tenckhoff-catheter insertion and Hb-relevant bleeding under hemodialysis.

Results While routine testing for plasmatic coagulation (aPTT, Quick, FXIIIa, and fibrinogen) revealed normal results, platelet function assays showed pathological findings (reduced response to ADP, low concentration of collagen in the aggregometry). In the IFM, reduced and disrupted expression was observed for thrombospondin and P-selectin. Weak signal was also documented for the delta granule markers Lamp 2 and CD63. Granule mobilization was investigated using LA and FC showing reduced release of ATP (0.05, normal range: 0.8–3.8) and CD63 (fold increase of MFI: 0.5, normal > 1.2) from delta-granula and weak increase in P-selectin expression after activation with TRAP indicating a combined alpha- and delta-granule disorder. Kidney transplantation was performed under tranexamic acid therapy without major bleeding complication. Platelet transfusion was necessary once for double J-stent removal. Laboratory investigations for platelet function 3 months after kidney transplantation and renal function showed significant improvement with normal expression of CD62p and CD63 expression in microscopy.

Conclusion Uremic situation due to renal insufficiency may be associated with combined acquired alpha- and delta-storage pool disease leading to hemorrhagic diathesis.

Publication History

Article published online:
13 November 2020