Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel  Biomarker  for    Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

P.  Ghosh1,  M.  A.  Luque-­‐Fernandez4,  A.  Vaidya2,  M.  Chorev1,  C.  Zera3,  T.  McElrath3,  M.  Williams4,  E.  Seely2,  J.  Halperin1  

 1Divs.  of  Hematology,    2Endocrinology  and  3Maternal  Fetal  Medicine,  Brigham  &  

Women’s  Hospital.  4Harvard  School  of  Public  Health.  Boston,  MA  

JAH  and  MC  are  founders  and  have  financial  interest  in  Mellitus  LLC.    

Mellitus  had  licensed  IP  used  in  this  research  and  has  interests  in  developing  

diagnos=c  tools  for  diabetes.  These    interests  were  reviewed  and  are  

managed  by  Brigham  and  Women’s  Hospital  and  Partners  HealthCare  in  

accordance  with  their  conflict  of  interest  policies.  

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

• GestaHonal  Diabetes  Mellitus  (GDM)  is  a  major  cause  of  abnormal  pregnancy  outcomes.  Pregnant  women  are  currently  screened  for  GDM  using  cumbersome  glucose  load  methodologies.  

• Experimental  and  clinical  evidence  supports  a  strong  link  between  inacHvaHon  of  the  complement  regulatory  protein  CD59  by  glycaHon  (forming  glycated  CD59  [GCD59])  and  the  pathogenesis  of  diabetes  complicaHons  (reviewed  in  Endocrine  Reviews  36  (3)  2015)  

• We  present  the  results  of  a  study  of  plasma  GCD59  levels  in  pregnant  women  undergoing  two-­‐step  screening  for  GDM.    

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  CD59

CD59

GCD59

CD59 and GCD59 shed-off cell membranes are present in blood.

CD59 is a cell membrane protein inhibitor of complement. A glycation motif (K41 and H44) makes human CD59 sensitive to inactivation by glycation (PNAS 2000).

. !

ELISA to measure GCD59 in human fluids (AJH 2013)

A “capture� and a �d e t e c t i o n �� m A b were raised using synthetic peptides (the detection antigen carried a pre-formed L y s [ N ε - g l u c i t o l ] lysine ).

Human studies showed higher levels of GCD59 in ind iv idua ls w i t h d i a b e t e s (JCEM 2014).

Capture mAb

Detection mAb

CD59

A surrogate CD59 linking both peptide antigens was used for calibration. The figures shows a t y p i c a l a s s a y calibration curve.

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

To  inves>gate  if  blood  levels  of  GCD59  in  the  late  second  trimester  classify  pregnant  women  with  and  without  abnormal  glucose  tolerance  and  GDM.    

Ø  Nested case-control study of plasma GCD59 levels in 1000 pregnant women undergoing two-step screening for GDM in the late second trimester (gestational weeks 24-28)

Ø  STEP 1: 50gr-1-hr Glucose Load Test (GLT): Normal: <140 mg/dL. Failed: ≥ 140 mg/dL. STEP 2: 100gr-3-hr Oral Glucose Tolerance Test (OGTT): Normal (OGTT-N): All 4 values normal (Coustan & Carpenter). Impaired glucose tolerance (IGT): 1 abnormal value. GDM: at least 2 abnormal values.

Ø  Analysis: Subjects characteristics were described by case-control (Table 1). Ø  The GCD59 distributions were described by case-control status: Normal GLT vs. failed GLT or Normal GLT vs. GDM. Ø  GCD59 mean differences among groups were assessed using parametric tests. Ø  GCD59 accuracy was assessed by ROC curves adjusted for maternal age, race and early

pregnancy BMI. Ø  The association between large for gestational age (LGA) prevalence and GCD59, was assessed

using gender and age adjusted infant birth weight z-scores derived from the latest reference curves for the US population. LGA was defined as z-score ≥2.

Methods

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

Blood  Levels  of  Glycated  CD59  (GCD59)  as  a  Novel    Biomarker  for  Screening  and  Diagnosis  of    

Gesta>onal  Diabetes  Mellitus  

Pregnant  women  are  screened  for  GDM  using  cumbersome  glucose  load  methodologies   that  dichotomously  classify   them  as  “normal”  or   “abnormal”   failing   to   capture   the   conHnuous   associaHon  between   maternal   hyperglycemia   and   adverse   pregnancy  outcomes.      Our   study   shows   that   a   one   Hme  measurement   of   GCD59   in   the  late   second   trimester   classified   women   with   or   without   GDM   as  well  as  women  with  normal  or  failed  GLT  with  high  sensiHvity  and  specificity.      Importantly,  higher  levels  of  maternal  GCD59  were  associated  with  higher  incidence  of  LGA  newborns.      We   conclude   that   blood   levels   of   GCD59   in   the   late   second  trimester   represent  a  promising  new  biomarker   for  screening  and  diagnosis   of   pregnancy   induced   abnormal   glucose   tolerance   and  GDM.  Funded  by  NIH  grants:  DK095429,  DK089206  and  DK101442    

Pregnant women are screened for GDM using cumbersome glucose load methodologies that dichotomously classify them as “normal” or “abnormal” failing to capture the continuous association between maternal hyperglycemia and adverse pregnancy outcomes. Our study shows that a one time measurement of GCD59 in the late second trimester classified women with or without GDM as well as women with normal or failed GLT with high sensitivity and specificity. Importantly, higher levels of maternal GCD59 were associated with higher incidence of LGA newborns. We conclude that blood levels of GCD59 in the late second trimester represent a promising new biomarker for screening and diagnosis of pregnancy induced abnormal glucose tolerance and GDM. Funded by NIH grants: DK095429, DK089206 and DK101442