Table 2.

Studies investigating the involvement of transfused platelets as a trigger for TRALI development

Study	Study type	First hit	Second hit	Readouts TRALI	Transfused platelet involvement in TRALI
Silliman et al, 2003 [43]	Ex vivo • Sprague-Dawley rats Male, 300 g	• LPS (Salmonella enteritides, strain not specified) 2 mg/kg, ip, 2 h prior to lung isolation, 165 min prior to human platelet plasma, lipid extracts, HPLC-purified lipids, or lyso-PCs	• Human platelet plasma (stored 5 d, apheresis- and whole blood-derived, heat-treated) lung perfusion, 165 min post LPS, analysis after 30 min • Lipid extracts (from human platelet plasma) lung perfusion, 165 min post LPS, analysis after 30 min • HPLC-purified lipids (from human platelet plasma) lung perfusion, 165 min post LPS, analysis after 30 min • Purified lyso-PCs (commercial) 5 or 10 μmol/L, lung perfusion, 165 min post LPS, analysis after 30 min	• PA pressure • Pulmonary edema index • LTB4 levels in lung perfusate • Lung histology	Pathogenic, lipids in stored platelets induce TRALI •No effects on PA pressure • All second hits increase pulmonary edema index • Human platelet plasma increases LTB4 levels • Lyso-PCs induce pulmonary PMN sequestration, septal damage, edema, and hyaline membrane formation
Gelderman et al, 2011 [44]	In vivo • SCID mice Sex not specified, 6-8 wk	• LPS (E coli, 0111:B4) 3 mg/kg, iv, 2 h prior to UVB-irradiated human platelets	• UVB-irradiated human platelets (stored 1 d prior to irradiation, apheresis-derived, leukoreduced) 109 platelets, iv, 2 h post LPS, analysis after 1 or 2 h	• Lung W/D weight ratio • BAL protein levels • Lung histology	Pathogenic tendency, UVB-irradiated human platelets may have the tendency to increase TRALI severity compared to unradiated platelets • No effect on lung W/D weight ratio • Increases BAL protein levels • Induces severe loss of alveolar structure, cellular infiltration, and protein-rich alveolar exudate (no scoring of lung damage)
Tung et al, 2011 [45]	In vivo • Merino sheep Female, 4 to 7 y (30-54 kg)	• LPS (E coli, O55:B5) 15 μg/kg, 30-90 min prior to human platelets	• Supernatant of aged human platelets (stored 5 d, whole blood-derived, heat-treated) 10% of total blood volume being 65 mL/kg, analysis after ≥2 h	• ABG • Lung histology (microscopic lung damage score)	Pathogenic, aged human platelet supernatant induces TRALI • Decreases end-tidal CO2, decreases pulmonary compliance, and increases arterial partial pressure of CO2 • Causes pulmonary edema, cellular infiltration, thickening of alveolar wall, and loss of alveolar structure
Chi et al, 2014 [46]	In vivo • SCID mice* Male, 6-8 wk • SCID/LYS-eGFP mice# Sex and age not specified	• LPS (E coli, 0111:B4) 3 mg/kg, ip, 2 h prior to Mirasol-treated human platelets	• Mirasol-treated human platelets (stored 2-20 h prior to Mirasol treatment, storage time prior to transfusion not specified, apheresis-derived, leukoreduced) 109 platelets, iv, 2 h post LPS, analysis after 2 h	• Lung histology* • Confocal microscopy lungs#	Pathogenic, human platelets mediate TRALI, regardless of Mirasol treatment • Induces pulmonary PMN sequestration in mice*/#, regardless of Mirasol treatment
Caudrillier et al, 2015 [47]	In vivo • NOD/SCID mice Sex not specified, 6-10 wk	• LPS (E coli, O55:B5) 0.1 mg/kg, ip, 24 h prior to Mirasol-treated human platelets	• Mirasol-treated human platelets (stored overnight prior to Mirasol treatment, stored 1 or 5 d prior to transfusion, apheresis-derived) 108 platelets, iv,24 h post LPS, analysis after 4 h	• Bloodless extravascular lung water • EVPE	Dispensable, Mirasol-treated human platelets do not induce TRALI
Xie et al, 2015 [48]	In vitro • HMVEC-L >90% confluence on 96-well plates	• LPS (Salmonella enteritides, strain not specified) 200 ng/mL, 6 h prior to PMP or sCD40L • PMNs 10:1 PMN to HMVEC-L ratio, post-LPS, allowed to settle to HMVEC-L (period of time not specified) prior to PMP or sCD40L	• Human PMPs (stored 3 d, apheresis-derived) 6 h post LPS, post PMN settling, analysis after 30 min • sCD40L (recombinant) 25 μg/mL, 6 h post LPS, post-PMN settling, analysis after 30 min	• HMVEC-L damage measured as reduction of viable cells/mm2	Pathogenic, PMPs and sCD40L activate PMN-mediated damage in LPS-primed HMVEC-L
McVey et al, 2017 [6]	In vivo • BALB/c Male, 8-12 wk	• LPS (E coli, 0111:B4) 2 mg/kg, ip, 2 h prior to murine platelets	• Aged murine (C57BL/6) platelets (stored up to 7 d, whole blood-derived) 10 mL/kg of 109 platelets/mL, iv, 2 h post LPS, analysis after 6 h • ARC39-treated aged murine (C57BL/6) platelets (stored up to 5 d in the presence of the ASM inhibitor ARC39 (10 μmol/L), whole blood-derived) 10 mL/kg of 109 platelets/mL, iv, 2 h post LPS, analysis after 6 h • Murine ASM-deficient (smpd1−/−) platelets (stored up to 7 d, whole blood-derived) 10 mL/kg of 109 platelets/mL, 2 h post LPS, iv, analysis after 6 h	• BAL protein levels • Lung W/D weight ratio • Lung MPO activity • Lung histology (microscopic lung damage score)	Pathogenic, ceramide accumulates in platelets and mediates TRALI • Aged WT platelets mediate TRALI, whereas ARC39-treated platelets or ASM-deficient platelets alleviate TRALI

Indicated symbols (*, #) should only be compared within each row. Bloodless extravascular lung water = [wet lung weight/(dry lung weight, corrected for the dry weight of blood remaining in the lung using hemoglobin levels)]. EVPE = ¹²⁵I-albumin radioactivity in the lung homogenate – (¹²⁵I-albumin concentration in plasma sample × calculated plasma volume in lungs) in ¹²⁵I-albumin–instilled mice. Pulmonary edema index = lung weight in grams/rat weight in kilograms. LYS-eGFP = enhanced GFP gene expression controlled by the lysozyme M promoter. ABG, arterial blood gasses; LTB₄, leukotriene B₄; PA, pulmonary artery.