Bethesda Inhibitor




Test Mnemonic

BETHDA

CPT Codes

  • 85335 - QTY (1)
  • 85240 - QTY (1)
  • 85210 - QTY (1)
  • 85220 - QTY (1)
  • 85230 - QTY (1)
  • 85250 - QTY (1)
  • 85260 - QTY (1)
  • 85270 - QTY (1)

Aliases

  • Factor IX Inhibitor
  • Factor VIII Inhibitor
  • Inhibitor Assay

Includes

  • Bethesda Units

Performing Laboratory

Cleveland Clinic Laboratories


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
1 mLPlasmaSodium citrate (Lt. Blue) FrozenSend two 1 mL aliquots

Stability

Environmental Condition Description
Ambient4 hours
RefrigeratedUnacceptable
Frozen14 days at -20 C; 6 months at -70 C

Days Performed

Mon - Fri

Turnaround Time

1 - 3 days

Methodology

Name Description
Clotting Assay 

Reference Range

Bethesda Inhibitor
Sex Age From Age To Type Range Range Unit
   Years99 YearsNormal< or = 0.4Inhib Unit
Factor II Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal29 - 72%
 2 Days5 DaysNormal36 - 96%
 6 Days30 DaysNormal37 - 106%
 1 Months3 MonthsNormal50 - 109%
 4 Months11 MonthsNormal66 - 120%
 1 Years5 YearsNormal78 - 120%
 6 Years10 YearsNormal74-111%
 11 Years16 YearsNormal67-108%
 17 Years99 YearsNormal77-151%
   Years99 YearsUrgentAfter Pathologist Review: < 5%
Factor IX Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal21 - 97%
 2 Days5 DaysNormal21 - 97%
 6 Days30 DaysNormal29 - 86%
 1 Months3 MonthsNormal29 - 120%
 4 Months11 MonthsNormal50 - 144%
 1 Years5 YearsNormal66 - 110%
 6 Years10 YearsNormal88 - 95%
 11 Years16 YearsNormal83 - 130%
 17 Years99 YearsNormal77 - 173%
   Years99 YearsUrgentAfter Pathologist Review: < 5%
Factor V Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal42 - 100%
 2 Days5 DaysNormal53 - 134%
 6 Days30 DaysNormal73 - 124%
 1 Months3 MonthsNormal57 - 122%
 4 Months11 MonthsNormal65 - 118%
 1 Years5 YearsNormal93 - 118%
 6 Years10 YearsNormal74 - 108%
 11 Years16 YearsNormal65 - 92%
 17 Years99 YearsNormal73 - 139%
   Years99 YearsUrgentAfter Pathologist Review: < 5%
Factor VII Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal23 - 116%
 2 Days5 DaysNormal29 - 160%
 6 Days30 DaysNormal35 - 154%
 1 Months3 MonthsNormal32 - 160%
 4 Months11 MonthsNormal39 - 142%
 1 Years5 YearsNormal45 - 130%
 6 Years10 YearsNormal43 - 134%
 11 Years16 YearsNormal48 - 129%
 17 Years99 YearsNormal55 - 160%
   Years99 YearsUrgentAfter Pathologist Review: < 5%
Factor VIII Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal22 - 207%
 2 Days5 DaysNormal22 - 179%
 6 Days30 DaysNormal26 - 182%
 1 Months3 MonthsNormal34 - 145%
 4 Months11 MonthsNormal38 - 127%
 1 Years5 YearsNormal59 - 165%
 6 Years10 YearsNormal58 - 153%
 11 Years16 YearsNormal53 - 152%
 17 Years99 YearsNormal50 - 173%
   Years99 YearsUrgentAfter Pathologist Review: < 5%
Factor VIII Chromogenic
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal22-179%
 2 Days5 DaysNormal22-155%
 6 Days30 DaysNormal26-158%
 1 Months3 MonthsNormal34-126%
 4 Months11 MonthsNormal38-110%
 1 Years5 YearsNormal59-143%
 6 Years10 YearsNormal58-133%
 11 Years16 YearsNormal53-132%
 17 Years999 YearsNormal50-150%
Factor X Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal15 - 73%
 2 Days5 DaysNormal23 - 85%
 6 Days30 DaysNormal38 - 93%
 1 Months3 MonthsNormal43 - 115%
 4 Months11 MonthsNormal46 - 127%
 1 Years5 YearsNormal61 - 124%
 6 Years10 YearsNormal57 - 108%
 11 Years16 YearsNormal52 - 126%
 17 Years99 YearsNormal73 - 163%
   Years99 YearsUrgentAfter Pathologist Review: < 5%
Factor XI Assay
Sex Age From Age To Type Range Range Unit
   Days1 DaysNormal10 - 91%
 2 Days5 DaysNormal23 - 120%
 6 Days30 DaysNormal27 - 109%
 1 Months3 MonthsNormal42 - 134%
 4 Months11 MonthsNormal39 - 185%
 1 Years5 YearsNormal57 - 207%
 6 Years10 YearsNormal53 - 165%
 11 Years16 YearsNormal51 - 134%
 17 Years99 YearsNormal68 - 175%
   Years99 YearsUrgentAfter Pathologist Review: < 5%

Special Info

Indicate coagulation factor to be tested. 3.2% sodium citrate is the preferred anticoagulant recommended by NCCLS. If inhibitor to porcine Factor VIII is needed, please supply porcine Factor VIII with patient sample. Appropriate factor assay requested will be performed and billed when requesting a Bethesda inhibitor.

Clinical Info

Factor VIII inhibitor: Factor VIII inhibitors most commonly occur in patients with Factor VIII deficiency (Hemophilia A) after treatment with factor replacement. Factor VIII inhibitors can also arise de novo in the elderly in a patient with lymphoproliferative disorders, post-partum and a patient with automimmune disorders.Factor IX inhibitor: Most commonly occurs in a patient with Factor IX deficiency (Hemophilia B) after treatment with factor IX replacement. De novo Factor IX inhibitors can occur but are rare. Porcine Factor VIII Inhibitor: Useful to determine the cross reactivity of factor VIII inhibitor against porcine factor VIII. If a factor VIII inhibitor is suspected, this assay should be ordered in addition to Factor VIII inhibitor level if porcine factor VIII is a therapeutic option. Factor VIII inhibitor: Inhibitor titers < 5 Bethesda units are considered low titer inhibitors; those > or = 5 Bethesda units are considered high titer inhibitors. Porcine Factor VIII inhibitor: A high titer (> 5 Bethesda units) against Porcine Factor VIII may make Porcine Factor VIII ineffective as a potential therapy for a Factor VIII inhibitor.