A case of acquired transient bleeding diathesis associated with acquired platelet storage pool deficiency and defective thromboxane A2 production

Figures & data

Figure 1. Platelet aggregation and ATP secretion of citrated PRP from the patient performed during the first visit (October 2014), and subsequent follow-up visits in February 2015 and June 2021, compared to control. Platelets were stimulated with ADP (A), collagen (B) and TRAP (C). Platelet serotonin and adenine nucleotides contents (nmol/10⁸ platelets) at each visit are reported in the table.

Table I. Results of the platelet function tests in the studied patient over time.

	October 2014		February 2015	March 2016	September 2020	June 2021	Normal range
Bleeding diathesis	Spontaneus bruising, bleeding from minor wounds, epistaxis, menorrhagia		Spontaneous bruising	None	None	None
Platelet agonist	Platelet ATP secretion, (nmol/10^8 platelets)
ADP (2 µM)	0		0	0.021	0.746	0.222	0.015 – 1.002
ADP (4 µM)	0		0.08	0.706	–	–	0.040 – 0.815
ADP (20 µM)	0.095		0.245	–	–	–	0.053 – 0.720
Epinephrine (5 µM)	0		0.163	0.811	0.829	0.428	0.039 – 0.972
TRAP (10 µM)	0		0.173	0.969	0.829	0.615	0.027 – 1.356
TRAP (20 µM)	0.056		–	–	–	–	0.478 – 1.239
Collagen (2 µg/mL)	0		0.245	0.930	0.687	0.522	0.281 – 1.090
Collagen (4 µg/mL)	0.044		–	–	–	–	0.237 – 0.988
Collagen (10 µg/mL)	0.117		–	–	–	–	0.321 – 0.976
U46619 (1 µM)	0		0.142	0.838	0.675	0.362	0.069 – 0.952
Arachidonic acid (1 mM)	0.092		0.224	0.680	0.604	0.531	0.104 – 0.891
Platelet agonist	Platelet aggregation, (%)
ADP (2 µM)
maximal	13		28	36	89	78	>21
3 minutes	0		0	36	89	78
ADP (4 µM)
maximal	29		46	74	–	–	>51
3 minutes	2		42	74	–	–
ADP (20 µM)	47		72	–	–	–	>75
Epinephrine (5 µM)	6		75	80	80	87	>10
TRAP (10 µM)	0		56	81	89	96	>21
TRAP (20 µM)
maximal	24		–	–	–	81	>72
3 minutes	17		–	–	–	81
Collagen (2 µg/mL)	0		72	83	91	87	>62
Collagen (4 µg/mL)	5		–	–	–	–	>72
Collagen (10 µg/mL)
maximal	42		–	–	–	–	>73
3 minutes	39		–	–	–	–
U46619 (1 µM)
maximal	27		74	83	89	87	>33
3 minutes	0		74	83	89	87
Arachidonic acid (1 mM)	62		76	79	80	88	>59
	Platelet serotonin and adenine nucleotides content, (nmol/10^8 platelets)
Serotonin	0.14		0.15	0.68	–	–	0.23–0.58
ADP	1.1		1.76	3.29	3.33	3.41	1.99–4.67
ATP	6.5		7.62	8.02	6.22	6.15	5.29–11.34
ATP/ADP ratio	6		4.32	2.43	1.88	1.88	1.30–3.29
Cartridge		PFA-100 closure time, (sec)
ADP/collagen	93		84	79	–	–	60–116
Epinephrine/collagen	>300		234	116	–	–	76–178
		Serum thromboxane B2, (pmol/10^8 platelets)
Serum Thromboxane B2	2.62		39	127	–	–	63–472

Numbers in bold characters indicate pathological results. Abbreviations: ATP= adenosine triphosphate; ADP=adenosine diphosphate; TRAP=thrombin receptor activating peptide; U46619=thromboxane A2 analogue; PFA-100=Platelet Function Analyzer-100. The normal ranges have been derived from testing 33 healthy volunteers in our laboratory.

Data availability statement

The raw data supporting the results of this study will be made available upon reasonable request.