Journal: medRxiv

Article Title: Long-term Stored Platelets Coupled to Thrombospondin-1 Detection for Rapid and Accurate Identification of Pathogenic HIT Antibodies

doi: 10.1101/2021.09.01.21262974

Figure Lengend Snippet: Thrombospondin-1 release assays (TRA) was performed with three platelet-activating HIT (closed circles) and control (open circles) samples using ( A ) Twenty lots of cryopreserved platelets and ( B ) Seven cryopreserved platelet lots stored for >4 weeks at -80°C (“4W”) and compared to activation of platelets stored for < 1 week at -80°C (“B”, baseline). ( C ) shows PF4-dependent activation induced by one HIT (closed circle) and one normal control sample (open circle) with three cryopreserved platelet lots stored at -80°C for 12-months. “4W” platelets ranged in storage age from 29 to 36 days, while “B” platelets ranged in storage age from 1 to 7 days. Date shown in ( A ) and ( B ) wee obtained using preliminary methods, as described in the supplementary appendix . Y-axis depicts TSP1 concentration (in µg/mL) measured in platelet supernatant and X-axis depicts platelet lot tested.

Article Snippet: TSP1 was quantified from platelet supernatants using a Thrombospondin-1 DuoSet ELISA kit (R&D Systems, Minneapolis, MN) using manufacturer instructions.

Techniques: Activation Assay, Concentration Assay

Journal: medRxiv

Article Title: Long-term Stored Platelets Coupled to Thrombospondin-1 Detection for Rapid and Accurate Identification of Pathogenic HIT Antibodies

doi: 10.1101/2021.09.01.21262974

Figure Lengend Snippet: (A) PEA and SRA results of the patient cohort used in the study are shown on the X-axis and Y-axis, respectively. Red dotted lines represent positive cut-off values (35% p-selectin expression and 20% serotonin release). The two patient samples highlighted in red tested positive in the PEA, but negative in the SRA, and had case histories consistent with HIT. (B) TRA results are displayed for the patient cohort after qualitatively grouping based on PEA results as positive (circles), or negative (squares). Patients that tested negative in the PEA but had positive IgG-specific HIT ELISA results are displayed as red squares (11 samples). Each data point represents the mean of technical triplicates. TSP-1 concentrations (µg/mL) are depicted on the Y-axis with the mean +/-1SD for each group displayed. (C) TRA results of ELISA OD-matched PEA+/SRA+ vs PEA-/SRA-patients are presented. Seven patients had platelet-activating antibodies (closed circles) while four were did not (red squares). Y-axis depicts TSP1 concentration (in µg/mL) measured in platelet supernatant and X-axis depicts the ELISA optical density. Each data point represents the mean of technical triplicates. A two-tailed, unpaired Student’s t test was used for comparison. ****p < 0.0001.

Article Snippet: TSP1 was quantified from platelet supernatants using a Thrombospondin-1 DuoSet ELISA kit (R&D Systems, Minneapolis, MN) using manufacturer instructions.

Techniques: Expressing, Enzyme-linked Immunosorbent Assay, Concentration Assay, Two Tailed Test, Comparison