Analysis of patients with γ-heavy chain disease by the heavy/light chain and free light chain assays.

Abstract

BACKGROUND:

The objective of this study was to evaluate the performance of the heavy/light chain and free light chain immunoassays in patients with heavy chain disease, and to assess the ability of the heavy/light chain assay to measure and confirm the abnormal, truncated heavy chain.

METHODS:

Frozen serum samples from 15 γ-heavy chain disease patients were tested for IgGκ, IgGλ, total IgG, free light chains, and M-spike concentrations.

RESULTS:

The (Gκ+Gλ)/IgGtotal ratio for these 15 patients ranged from 0.02 to 0.80. The 10 patients with IgG concentrations above 1 g/dL all had ratios below 0.3 indicating that a substantial portion of IgG was not quantitated by the Gκ and Gλ reagents. The average M-spike was 1.61 g/dL and the average calculated abnormal γ-chain concentration was 2.94 g/dL. Additionally, free light chain analysis revealed the presence of monoclonal free κ light chain in three of the 15 patients.

CONCLUSIONS:

This study demonstrates utility of a nephelometric assay to identify truncated immunoglobulin heavy chains in γ-HCD and that 20% of these patients also have monoclonal free light chain.

• Authors: Erin Kaleta, Robert Kyle, Raynell Clark, Jerry Katzmann
• Journal: Clinical chemistry and laboratory medicine (Clin Chem Lab Med) Vol. 52 Issue 5 Pg. 665-9 (May 2014) ISSN: 1437-4331 [Electronic] Germany
• PMID: 24327529 (Publication Type: Journal Article)

Chemical References

• Immunoglobulin Heavy Chains
• Immunoglobulin Light Chains
• Immunoglobulin kappa-Chains
• Immunoglobulin lambda-Chains

Topics

• Electrophoresis
• Heavy Chain Disease (metabolism, pathology)
• Humans
• Immunoassay
• Immunoglobulin Heavy Chains (blood)
• Immunoglobulin Light Chains (blood)
• Immunoglobulin kappa-Chains (blood)
• Immunoglobulin lambda-Chains (blood)