Clinical Analysis Of 42 Cases Diagnosed As Multiple Myeloma

Light chain multiple myeloma is one type of multiple myeloma which only synthesize and secret monoclonal light chain. There are only 0.5-1.0 gram monoclonal light chain synthesize in normal everyday, most of them used to synthesize immunoglobin, and there are only little content in serum.The molecular weight of free light chain is 22000D, it can go through the glomerular filtration barrier into the primary urine, after tubular reabsorption, it is negtive in urine. The free light chain can be detected, When it synthesized more or the abnormal function of renal tubule, and the FLC in urine we called it Bence-Jones protein (BJP). Malignant plasma cell can synthesize monoclonal light chain (kappa/lambda) in LCMM, if going up to threshold of the tubular reabsorption, there are light chains in urine, and the excess light chain deposits in the renal tubule results in renal damage. Most of LCMM patients are in StageⅢaccording to D-S staging system in that the renal damage, osteolytic lesion and the bad differentiation of tumor cell. In order to improve the diagnosis and treatment, We studied the clinical and laboratary feature of 42 LCMM patients compared with 67 IgG MM by retrospective analysis.Objective:To summarize the clinical and laboratory features of newly diagnosed light chain multiple myeloma, and do the comparative analysis of LC and IgG MM groups.Method:Records of 42 light chain MM patients and 67 IgGκ/λMM in whom MM was initially diagnosed at the hospitals attached to Jilin University, from February 1998 to January 2008 were reviewed. Diagnosis of multiple myeloma was based on the WHO diagnostic criteria, Staging of MM is according to the Durie-Salmon staging system. Compared renal function, blood calcium, serum free light chain, urine free light chain,β2-microglobulin, urine protein, Bence-Jones protein with IgG MM. Measurement data and enumeration data were compared with t test andχ2 test, if P<0.05, the difference was significant.Results:(1) Of the 297 multiple myeloma, 14.1% were diagnosed as light chain, the median age was 55.5 years; there were 25 males and 17 females, the sex ratio is 1.47:1. The common clinical manifestation was ostealgia and fatigue, the incidence was 54.8%, 47.6% respectively. Amyloidosis was present in 4.8% of LCMM, which is the uncommon clinical manifestation in MM.(2) Anemia was present initially in 81.0% of LCMM, the average of hemoglobin was 83.27±24.57g/L, hypercalcemia in 10.0%, the serum creatinine level of 176.8μmol/L or more in 52.4%, the serum creatinine level of 455.1μmol/L or more in 31.0%. there were 18 cases has the increasedβ2-microglobulin level in 24 cases who initially took the test.(3) Compared with IgG MM, LCMM has the high rate in renal function damage, severe renal function damage, the blood calcium level and the high incidence about urine protein, the difference is significant.Conclusion:Compared with IgG MM, the higher incidence of renal function damage and severe renal function damage in LCMM, The average blood calcium level and incidence of protein urine were more commonly occurred in LCMM than IgG.