METHOD OF DETECTING OR MONITORING A MALIGNANT PLASMA CELL DISEASE

• US 20110177535A1
• Filed: 01/21/2011
• Published: 07/21/2011
• Est. Priority Date: 01/27/2005
• Status: Active Grant

• Current Assignee: The Binding Site Group Ltd. (Thermo Fisher Scientific Incorporated)
• Original Assignee: The Binding Site Group Ltd. (Thermo Fisher Scientific Incorporated)
• Inventors: BRADWELL, Arthur R.
• Granted Patent: US 8,415,110 B2
• Time in Patent Office: Days
• US Class Current: 435/7.92
• CPC Class Codes: G01N 2800/52 Predicting or monitoring the response to treatment, e.g. for selection of therapy based on assay results in personalised medicine; Prognosis
• CPC Class Codes: G01N 33/57426 leukemia
• CPC Class Codes: G01N 33/6854 Immunoglobulins

Abstract

A method of detecting or monitoring a malignant plasma cell disease comprising detecting in a sample the ratio between the relative amounts of immunoglobulins having:

• • (i) a heavy chain class bound to λ light chains; and
  • (ii) immunoglobulins having the same heavy chain class but bound to κ light chains. More particularly, in one embodiment the method comprises the steps of measuring the relative amounts of the respective immunoglobulins by using:
  • (i) at least one antibody, or a fragment thereof, specific for the heavy chain class;
  • (ii) an antibody, or a fragment thereof, specific for λ light chains; and
  • (iii) an antibody, or a fragment thereof, specific for κ light chains.

Claims

1. A method of detecting, monitoring or diagnosing a malignant plasma cell disease in a patient, said method comprising

obtaining a first sample from said patient;

contacting said sample with at least one antibody, or a Fab or F(ab′

)₂ fragment thereof, specific for the heavy chain class;

contacting said sample with light chain class antibodies, or a Fab or F(ab′

)₂ fragments thereof, said light chain antibodies comprising antibodies specific for λ

light chains and/or antibodies specific for κ

light chains, wherein one class of antibodies selected from said heavy chain class and light chain antibodies (or their counterpart Fab or F(ab′

)2 fragments thereof), is immobilized on a solid support and the other is labeled;

removing unbound immunoglobins and free light chains;

conducting an immunoassay on said sample to determine a first ratio between the measured relative amounts of immunoglobulins having a heavy chain class bound to λ

light chains, compared to immunoglobulins having the same heavy chain class but bound to κ

light chains;

comparing said first ratio to a second ratio, said second ratio comprising the relative amounts of immunoglobins having a heavy chain class bound to λ

light chains, compared to immunoglobulins having the same heavy chain class but bound to κ

light chains in

a) a sample obtained from an individual without the disease, or

b) a second sample taken from said patient after said first sample;

wherein a deviation of said first ratio from said second ratio indicates the presence of a malignant plasma cell disease and/or the progression/regression of the disease.

2. The method according to claim 1, wherein the heavy chain class or Fab or F(ab′

)₂ fragment thereof is immobilized on said solid support.

3. The method according to claim 1, wherein the first and second ratios are determined using an immunosorbent assay, such as an Enzyme Linked Immunosorbent Assays (ELISA) comprising the antibodies.

4. The method according to claim 1, wherein the heavy chain class antibody, is bound to a bead and flow cytometry is used to determine the kappa/heavy chain to lamda/heavy chain ratios for a given heavy chain class in said sample.

5. The method according to claim 1, wherein the binding of the antibodies to the immunoglobulins in the sample is determined by using a nephelometer, a turbidimeter, flow cytometry or color coded microspheres.

6. The method according to claim 1, additionally comprising the step of detecting the presence and/or amount of free λ

and/or free κ

light chains in the sample.

7. The method according to claim 6, wherein the free λ

and/or free κ

light chains are detected by antibodies specific for free λ

or free κ

light chains.

8. The method of claim 1 wherein said sample is a blood or serum sample.

9. The method according to claim 1, wherein the heavy chain class, or Fab or F(ab′

)₂ fragment thereof, is heavy chain subclass specific.

10. A method of monitoring a malignant plasma cell disease in a patient during treatment to determine the efficacy of the treatment, said method comprising

determining a first ratio between the relative amounts of immunoglobulins having:

a heavy chain class bound to λ

light chains, compared to immunoglobulins having the same heavy chain class but bound to κ

light chains in a sample obtained from said patient before administration of said treatment;

administering said treatment;

determining a second ratio between the relative amounts of immunoglobulins having;

a heavy chain class bound to λ

light chains, compared to immunoglobulins having the same heavy chain class but bound to κ

light chains in a sample obtained from said patient after administration of said treatment,

comparing said first and second ratios to a threshold value obtained from population data analysis of measured ratios between the amounts of immunoglobulins having;

a heavy chain class bound to λ

light chains, compared to immunoglobulins having the same heavy chain class but bound to κ

light chains in samples obtained from individuals without the disease;

wherein the efficacy of the therapy is indicated by the second ratio being more similar to said third ratio than the first.

11. The method of claim 10 wherein said sample is a blood or serum sample.

12. The method according to claim 10, wherein the heavy chain class antibody, is bound to a bead and flow cytometry is used to determine the kappa/heavy chain to lamda/heavy chain ratios for a given heavy chain class in said sample.

13. The method according to claim 10, wherein the heavy chain class, or Fab or F(ab′

)₂ fragment thereof, is heavy chain subclass specific.

14. A method of detecting, monitoring or diagnosing a malignant plasma cell disease in a patient, said method comprising

obtaining a sample from said patient;

contacting said sample with at least one antibody, or a Fab or F(ab′

)₂ fragment thereof, specific for the heavy chain class;

contacting said sample with light chain class antibodies, or a Fab or F(ab′

)₂ fragments thereof, said light chain antibodies comprising antibodies specific for λ

light chains and/or antibodies specific for κ

light chains, wherein one class of antibodies selected from said heavy chain class and light chain antibodies (or their counterpart Fab or F(ab′

)2 fragments thereof), is immobilized on a solid support and the other is labeled;

removing unbound immunoglobins and free light chains;

conducting an immunoassay on said sample to determine a first ratio between the measured relative amounts of immunoglobulins having a heavy chain class bound to λ

light chains, compared to immunoglobulins having the same heavy chain class but bound to κ

light chains;

comparing said first ratio to a threshold value obtained from population data analysis of measured ratios between the amounts of immunoglobulins having a heavy chain class bound to λ

light chains, relative to immunoglobulins having the same heavy chain class but bound to κ

light chains in samples obtained from individuals without the disease;

wherein a deviation of said first ratio from said threshold value indicates the presence of a malignant plasma cell disease.