Pika T.,Hemato onkologicka Klinika LF UP |
Lochman P.,Oddeleni Klinicke Biochemie |
Latalova P.,Ustav Klinicke A Molekularni Patologie |
Minarik J.,Hemato onkologicka Klinika LF UP |
And 3 more authors.
Klinicka Biochemie a Metabolismus | Year: 2015
Introduction: AL amyloidosis is a rare disease belonging to the group of monoclonal gammopathies. The basis of the disease is the deposition of fibrils formed by molecules of monoclonal immunoglobulin light chains into the form of amyloid - amorphous proteinaceous material. Detection and quantification of monoclonal immunoglobulin (MIg) or immunoglobulin light chains is a key aspect in the diagnosis and monitoring of patients with AL amyloidosis. Aim: The content of this paper is our own experience with the determination of MIg in patients with AL amyloidosis. Patients and methods: The analyzed group included 27 patients with systemic AL amyloidosis. In all patients we performed the detection and quantification of monoclonal immunoglobulins in serum and urine using electrophoresis and immunofixation, serum free light chain levels were determined by FreeLite™ system. In 13 patients we performed determination of heavy / light chain pairs (HLC) of immunoglobulins, using HevyLite™ system. Results: Immunofixation and electrophoresis of samples showed the presence of molecules MIg in 17/27 (63%) patients and the median concentration was 3.8 g/l (0.3 to 14.2 g/l). By immunofixation there were 5 cases of complete molecules of the IgG isotype (1x IgG-κ, 4x IgG-λ), in 4 cases IgA-λ and in one case IgD-λ. In 7 patients we detected only λ light chains in serum. When analyzing the urine excretion, Bence - Jones protein was detected in 15 (56%) patients. In all cases the quantity was over 200 mg/24 hours, while in 3 patients we found the presence of complete molecules of MIg in urine (IgA λ 1x, 2x IgG-λ). Analysis of serum free light chains showed abnormal values in all patients with median of 310 mg/l (53.6 - 1562 mg/l), pathology of κ/λ ratio was found in 25 patients (92.5%). Analyses of the HLC levels were performed in 13 patients. In the case of IgA isotype we detected pathology of IgA-λ HLC levels along with the change in HLC ratio in 3/4 patients. In IgG isotype, pathology of IgG-λ levels and HLC ratio was detected in 2/2 patients. In the case of λ and immunofixation negative sera there was no elevation of HLC levels in any of the isotypes. Conversely, in 5/7 patients we observed suppression of IgG-κ HLC combined with the change of HLC ratio. IgA and IgM isotype pair suppression was not observed. Conclusion: Detection, quantification and complex analysis of monoclonal immunoglobulin belongs to the key aspects of care for patients with AL amyloidosis. The combination of standard techniques of electrophoresis and immunofixation together with determination of serum free light chains allows monitoring of majority of the patients with AL amyloidosis. To clarify the contribution of HLC test, analysis of more extensive group of patients is needed.