[Modern approaches to the detection of monoclonal gammopathy of undetermined significance (MGUS) in patients with kidney diseases].

Monoclonal gammopathy (MG) is not only the state preceding of hematological neoplasms, but also associated with non - hematological diseases, in particular kidney damage. AIM: To assess the diagnostic value of "Freelite" methods in addition to electrophoresis (EF) and immunofixation (IF) of serum and urine proteins for detecting MG in patients with kidney diseases. MATERIALS AND METHODS: 87 patients with kidney damage, in which MG was established using the method of electrophoresis of serum proteins (EF), immunofixation (IF) and the method of free light chains determination - FLC "Freelite" were selected. The diagnostic value of three - component serum panel was compared with EF and IF. RESULTS AND DISCUSSION: AL-amyloidosis with kidney involvement was diagnosed in 41% patients, cryoglobulinemic glomerulonephritis (cryo GN) - in 18%, chronic glomerulonephritis (CGN) - in 35%, also there was small number of patients with light chain disease and cast - nephropathy. Determination of MG using EP was possible only in 38 (44%). Adding to the serum electrophoretic methods instead of the "Freelite" method, the urine EF and IF reduced the number of missed patients with monoclonal gammopathy from 24 (27%) to 11 (13%), including in the subgroup of patients with AL-amyloidosis but did not reach the sensitivity of the three - component serum screening panel. In 10 (11.5%) MG was represented only by intact mIg with one type of light chain, either κ or λ. Most often - in 25% of patients, intact monoclonal gammopathy was observed in HCV (+) cryo GN. A combination of intact mIgM, mIgG or mIgA with mFLC, was detected in 37 (42.5%). In almost half (46%) of the patients, only mFLC was detected - an abnormal κ/λ ratio. CONCLUSION: The serum screening panel EF + IF + "Freelite" spreads the low - grade monoclonal gammopathy recognition (MGUS) and should be included in the algorithm of examining patients with kidney disease.

[Oligosecretory monoclonal gammopathy with renal involvement]. / Oligosekretornaya monoklonal'naya gammapatiya s porazheniem pochek.

The article deals with the so-called monoclonal gammopathy of undetermined significance (MGUS), which is being actively explored in the world and has been recently investigated in Russia. It indicates the principles of identifying the phenotypes of MGUS and criteria for assessing the risk of its progression to cancer. There is an update on the possible involvement of monoclonal proteins in the pathogenesis of certain non-neoplastic kidney diseases, renal injuries in particular. The paper gives their classification and enumerates differential diagnostic techniques, including the Freelite method, a highly sensitive one to determine free light chains (FLC), prognostic criteria, and approaches to treating each separate form in relation to the phenotype of a monoclonal protein. The authors present their own data on detection rates for MGUS at a multidisciplinary hospital and a clinical case of MGUS-associated membranoproliferative glomerulonephritis, by justifying a treatment regimen containing bortezomib (velcade).

[Kidney injury associated with monoclonal gammopathies: Perspectives on diagnosis and treatment].

It is currently well justified that monoclonal gammopathies are the most important predictor for kidney diseases, including glomerulonephritis. To determine a correlation of nephropathy with oligosecretory gammopathy is of fundamental importance, as the treatment of these patients necessitates the use of special chemotherapy regimens to eliminate a pathological clone of lymphocytes or plasmocytes. If this clone is not eliminated, injury of the organ may recur to develop its failure. The principles of this therapy have been presently tried out by the example of AL-amyloidosis and showed its efficiency and relatively low toxicity.

[Current methods of systemic amyloidosis diagnosis and monitoring of its course].

AIM: To determine clinical significance of measuring blood levels of protein precursors of AA- and AL-amyloidosis - SAA and immunoglobulin free light chains (ILC), respectively. MATERIAL AND METHODS: SAA concentrations were studied with ELISA in 43 rheumatoid arthritis (RA) patients including complicated with reactive AA-amyloidosis (n = 31). Inflammation activity and its severity were studied (indices Li, richi, HAQ, DAS4). A modern quantitative nephelometric method Freelite estimated ILC levels in 31 patients with AL-amyloidosis. RESULTS: Patients with RA complicated with AA-amyloidosis and free of it had a strong correlation between blood serum SAA concentration and activity of joint disease. Elevated SAA concentrations to 160 mg/l (normal 10 mg/l) were detected in many patients with clinical remission of the joint syndrome. Significal inhibition of AA-amyloidosis progression was seen only in SAA concentration drop under 60 mg/l. For AL-amyloidosis patients ILC fall by less than 3 normal value means a 6-time increase in chances of a favourable outcome. CONCLUSION: Monitoring of blood levels of proteins precursors of AA- and AL-amyloidosis is a key factor in prognosis of the disease and treatment efficacy.

[New possibilities of the diagnosis and monitoring of the course of AL-amyloidosis].

AIM: to define the clinical value of various concentrations of immunoglobulin light chains (ILCs) in patients with AL amyloidosis. SUBJECTS AND METHODS: The content of free ILCs was studied by a nephelometric technique after their fixation in the blood of 31 patients with AL amyloidosis; monoclonal gammapathy was associated with the hyperproduction of monoclonal ILCs of lambda- and kappa-type in 14 and 17 patients, respectively. The obtained value was compared with the data of physical examination and laboratory and instrumental studies indicating lesions to target organs and with the course of the disease. RESULTS: In patients with the good course of AL amyloidosis, the average level of free ILCs was 1.8 (range 0.77-3) times greater than the normal values (the range of ILCs of lambda and kappa-type was 20.24 to 67.4 and 20.14 to 81.38 mg/l, respectively); in those with the poor course, the excess of ILCs was 5.8 (range 3.7-13) times higher than the normal values (the range of lLCs of lambda and kappa-type was 54.32 to 286.7 and 117.06 to 2606.0 mg/l, respectively). The optimal range of diagnostic sensitivity (75%) and specificity (75%) in the estimation of prognosis was determined at the ILC levels that were three times greater (64.5 mg/l for kappa-ILCs and 80 mg/l for lambda-ILCs). Among the patients with a blood free ILC level of < 3 times more than the normal values, the good and poor courses of AL amyloidosis were noted in 13 and 4 cases, respectively. CONCLUSION: The determination of serum ILC concentration by the Freelite method may be used to diagnose AL amyloidosis and to specify the presence of appropriate organ dysfunction; this study over time makes it possible to monitor the course of the disease and to estimate its response to therapy.