An introduction to Hevylite

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An introduction to Hevylite

• Josie Hobbs PhD
• Scientific Affairs Manager
• Binding Site

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Myeloma guidelines 2005

• Initial investigation
• Electrophoresis of serum and conc. urine should
  be performed, followed by immunofixation to
  confirm and type any M-protein
• Quantification of serum M-protein should be
  performed by densitometry of the monoclonal peak
  on electrophoresis

UK and Nordic guidelines 2005, BJH 132 410 451
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Problems with densitometry

• Scanning densitometry is not accurate
• IgA bands may be hidden by transferrin

IgA Multiple Myeloma sera
N
1 2 3 4 5 6 7 8
9 10 11 12 13 14
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Myeloma guidelines 2005

• Initial investigation
• immunochemical measurement of total
  immunoglobulin isotype can also be used and is
  particularly useful for IgA and IgD M-proteins.

UK and Nordic guidelines 2005, BJH 132 410 451
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Problems with IgG, IgA and IgM assays

• Nephelometry measures the total immunoglobulin
  but the patient is Ig? or Ig?
• There is no Ig?/Ig? ratio

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Serum FLC ?/? ratios
SPE sensitivity
Serum lambda FLC
IFE sensitivity
Serum kappa FLC
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Introducing Hevylite
Automated immunoassay (BNII and
SPAPLUS) Polyclonal sheep antisera reagent
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Hevylite specificities
IgG?
IgG?
IgA?
IgA?
IgM?
IgM?
Future IgD? IgD?
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Hevylite allows identification, quantitation and
typing of M-proteins
Hevylite IgA? 5000 mg/L IgA? 20
mg/L IgA?/? 250
M-protein hidden in ? region
Normal sera MM patient
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Other potential advantages of Hevylite Ig?/Ig?
ratios

• Corrects for IgG metabolism

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Variable IgG half life

• IgG 20 day days to weeks
• IgA 6 days
• IgM 5 days

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FcRn binds IgG and albumin
IgG
Albumin
Neonatal Fc receptor FcRn
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Recycling of IgG
Fluid phase uptake
Endothelial cell
FcRn binds IgG inside endosome
Bound IgG is recycled
Degradation
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Concentration-dependent catabolism of IgG
Hevylite ratio corrects for this
IgG M-protein production underestimated
Serum IgG concentration
0
0
IgG half life
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Other potential advantages of Hevylite Ig?/Ig?
ratios

• Corrects for IgG metabolism
• Corrects for changes in plasma volume
• Corrects for changes in haematocrit

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Ratio corrects for variable plasma volume and
haematocrit
Ig?/Ig? 3/1
Ig?/Ig? 3/1
Ig?/Ig? 3/1
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Relationship of monoclonal Ig changes to plasma
volume and haematocrit
Alexanian et al. have demonstrated that plasma
volume and hematocrit are abnormal in monoclonal
gammopathy patients prior to treatment and that
these values may return to normal following
treatment
Alexanian et al. Blood 1977 49 301- 307
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Hevylite preliminary data
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Interference testing
IgG? (11.0 g/L)
IgG? (10.5 g/L)
IgA? (8.8 g/L)
IgM? (11.9 g/L)
IgM? (10.6 g/L)
? FLC (45 mg/L)
? FLC (51 mg/L)
Chyle (282 FTU)
Haemoglobin (4.8 g/L)
Bilirubin (200 mg/L)
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Summation testing
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Clinical validation

• Normal range generation
• 142 healthy blood donors
• Monoclonal gammopathy presentation samples
• 90 multiple myeloma
• Including 47 IgG?, 23 IgG?, 9 IgA?, 8 IgA?
• 8 MGUS
• 6IgG?, 1 IgA?, 1 IgA?

Kyrtsonis et al - personal communication
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Identification of IgA M-proteins
Normal sera IgA MM IgA MGUS
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Identification of IgA M-proteins
Normal sera IgA MM IgA MGUS IgG MM
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Monitoring IgG? Myeloma
IgG M-protein Total IgG IgG ? / IgG? Hevylite
Ratio
Cyclophosphamide
CVAMP
IFE / SPE Negative
IgG NR upper limit
no selective tumour kill
Hevyliite NR
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Prognosis
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No prognostic significance of Intact Ig
concentration
p0.89
P0.84
Cumulative survival
Upper tertile
Above median
Middle tertile
Lower median
Below median
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Prognostic significance of FLC ratio
p0.12
p0.03
Upper tertile
Above median
Middle tertile
Lower median
Below median
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Prognostic significance of HLC ratio
p0.08
p0.02
Upper tertile
Above median
Middle tertile
Lower median
Below median
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No correlation between monoclonal intact Ig and
sFLC
r2 0.06
Pearson's 0.113 p 0.331
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Prognostic significance of combined FLC HLC
ratios
p0.02
p0.04
Upper tertile
Above median
Middle tertile
Lower median
Below median
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Hevylite Whats next?

• Normal range generation
• Clinical validation
• Commercial availability Late 2009

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Using Hevylite in routine practice

• Monitoring
• Use in combination with sFLC
• Application for problematic SPEs
• Typing
• At diagnosis, screen with SPE/CZE sFLC then
  type with HLC
• Type with 3 Hevylite pairs (IgG, A and M)

automated assay gives additional quantitative
prognostic info
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Hevylite Summary

• Simple, fast, automated test
• Clear identification, quantitation and typing
  of
• Ratio may correct for variable IgG half-life,
• Ratio is a sensitive measure of disease
• Ratio has prognostic value in MM

M-proteins
plasma volume and haematocrit
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Any questions?