CELL MEMBRANE MICROPARTICLES IN BLOOD AND BLOOD PRODUCTS: POTENTIALLY PATHOGENIC AGENTS AND BIOMARKE

1
CELL MEMBRANE MICROPARTICLES IN BLOOD AND BLOOD
PRODUCTS POTENTIALLY PATHOGENIC AGENTS AND
BIOMARKERSJAN SIMAK, Ph.D. Laboratory of
Cellular Hematology, DH/OBRR, CBER FDA
2
Cell Membrane Microparticles (MPs)

• Phospholipid vesicles of 0.05 1.5 ?m in size
  shed from the plasma membrane of eukaryotic
  cells
• Contain membrane phospholipids and express
  antigens characteristic of their cell of origin
• Derived from PLTs, RBCs,WBCs, ECs, and some other
  cell types, circulate in blood
• Specific MP phenotypes are elevated in blood in
  different pathologies

3
Potentially Pathogenic Activities of MPsfor
review Simak J Gelderman MP, Transf Med Rev
2006

• Intercellular transfer of membrane proteins and
  lipids
• Prothrombotic effects
• Proinflammatory effects
• Impairment of endothelial function
• Modulation of vascular tone
• Induction of angiogenesis and enhancement of
  cancer cells metastasis
• Biologically active molecules in plasma
  Soluble or MP-associated ?

4
FDA/CBER Mission Relevance

• MPs as biomarkers
• QC in vitro testing of blood products and
  transfusion devices
• In vivo testing of adverse effects of biologics,
  devices and drugs
• Diagnosis of vascular, hematologic, and other
  diseases
• Potentially pathogenic activities of MPs in blood
  products
• Transfusion adverse events

5
MP Research Program
Selection of MP phenotypes Flow cytometric
analysis of MP surface antigens
In Vitro Studies
Development of MP assays and investigation of
pathogenic or diagnostic importance of selected
MP phenotypes
Clinical Studies
Analysis of MPs in cellular blood products
Testing of biologics, drugs and devices
6
Flow Cytometric Analysis of MPs in Plasma Simak J
et al., British J Haematol, 2004
CD105 (EC)
CD105 (EC)
CD41(PLT)
CD45 (WBC)
IgG IC
CD41 (PLT)
IgG IC
CD45 (WBC)
7
MP Analysis in Vascular Diseases

• Circulating MPs in PNH and SCD (study with NHLBI)
• Hemolytic diseases with vascular injury to mimic
  transfusion adverse events
• MPs derived from PLTs, RBCs, WBCs, and ECs found
  elevated in SCD
• Endothelial MPs found elevated in both SCD and
  PNH
• Identified specific endothelial MP phenotypes
  with potential diagnostic importance for severity
  and character of vascular injury
• Simak J et al., British J Haematol, 2004

8
MP Analysis in Vascular Diseases II

• Circulating MPs in acute ischemic stroke (study
  with NINDS)
• Quantitative evaluation of vascular injury
  Ischemic lesion volume measured by DWI-MRI
• Specific endothelial MP phenotype correlated
  with brain lesion volume
• Different endothelial MP phenotype in admission
  samples correlated with clinical outcome
• Simak J et al., J Thromb Haemost, 2006 (in
  press)

9
MP Analysis in Apheresis Platelets
(APs) Gelderman MP et al., ASH 2005

• MPs derived from PLTs, WBCs, RBCs, and ECs, were
  elevated in APs compared to normal plasma
• TFMPs and MP-associated TF activity (FX
  activation) were elevated in APs compared to
  normal plasma
• AP storage 5 vs 7 days No MP increase with
  exception of WBC MPs including TF WBC MPs
  (CD142CD45).
• Effects of Washed MPs from APs on HUVEC Culture
• Increase expression of ICAM-1 and TF on cells
• G1 arrest and cell apoptosis
• Extracellular calcium influx (in PC12 cells)

10
Future Plans Investigation of TFMPs in APs
Possible origin of TFMP in APs
APHERESIS STORAGE
MONOCYTE
TF
TF
CD41
TF
PSGL-1
TF
P-SEL
TF
PLT
PLT
PLT
PLT
Plt
ACTIVATION
RESTING
ACTIVATION
Modifed in vivo mechanism proposed in B. Furie
lab (Throm. Haemost. 2004)
11
Future Plans, cont.

• Study of MPs in APs and red blood cell
  transfusion products
• Association of different MP phenotypes with in
  vitro proinflammatory and proapoptotic effects of
  MPs
• Effects of donor characteristics, collection
  devices, leukofiltration, pathogen reduction
  treatments, and storage, on MP content in
  cellular blood products
• Design of clinical study protocols Association
  of different MP phenotypes in cellular blood
  products with transfusion adverse events.
• FDA Collaborative project To study the
  interaction of
• nanomaterials with plasma membrane of blood and
  
• endothelial cells

12
ACKNOWLEDGEMENTS
NHLBI Neal S. Young, MD, PhD Antonio M. Risitano,
MD, PhD NINDS Alison E. Baird, FRACP, PhD Hua Yu,
MD Violet Wright, RN, DNSc NIH CC Department of
Transfusion Medicine USUHS Olga Simakova, MS
CBER Monique P. Gelderman, PhD Karel Holada,
PhD Jaroslav Novak, PhD Jan Zivny, MD, PhD Laura
B. Carter, MT Jaroslav G. Vostal, MD, PhD