High dose chemotherapy in light chain or light and heavy chain deposition disease

BACKGROUND: Conventional chemotherapy for myeloma yield unsatisfactory results in light and/or heavy chain deposition disease [(H)CDD] Because of the well-established dose-response effect of high dose melphalan in multiple myeloma, aiming to dramatically reduce the pathogenic monoclonal immunoglobulin (MIg) level, high dose therapy is a tempting alternative approach. METHODS: We treated 11 young patients with L(H)CDD by high dose therapy with the support of autologous blood stem cell transplantation. All had renal symptoms, including four who required dialysis and seven who had various, mainly cardiac, extrarenal manifestations. RESULTS: No toxic deaths occurred. A decrease in the MIg level was observed in eight patients, with complete disappearance from serum and urine in six cases. Improvement in manifestations related to MIg deposits were observed in six patients, including renal, cardiac, and hepatic responses in 4/11, 4/4, and 2/2 cases, respectively. Histologic regression of MIg deposits was documented in cardiac, hepatic, and skin biopsies. In contrast, examination of the kidney still showed light chain deposits in one patient who had renal transplantation 3 years after high dose therapy, at a time when he was in persisting remission. Within a median follow-up of 51 months, three patients were retreated because of multiple myeloma relapse, of whom one died and one required hemodialysis, and renal function secondarily deteriorated in a patient who had resistant multiple myeloma. Otherwise, no manifestations related to MIg deposits occurred or recurred in any patient. CONCLUSION: Present results of this retrospective study argue in favor of a benefit of high dose therapy with stem cell support in young patients with L(H)CDD.     

Pathological characteristics of light chain crystalline podocytopathy

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Membranous nephropathy with light chain restricted deposits

The literature on membranous nephropathy (MN) with monoclonal deposits on immunofluorescence (IF) and their outcome is very scarce. We report our experience of managing five patients with this clinical entity. The mean age of the patients was 33.2 ± 6.55 years. The mean proteinuria, serum albumin and serum creatinine was 5.73 ± 2.17 g/day, 2.86 ± 0.51 g/dL and 1.34 ± 1.19 mg/dL, respectively. None of the patients had a lymphoproliferative disorder. Only one patient had an elevated free light chain ratio. Four (80%) patients were M‐type phospholipase A2 receptor (PLA2R) negative (tissue and serum), and one (20%) was PLA2R related. Three (60%) cases had monoclonal IgG3/k, one IgG3/λ, whereas one patient with PLA2R positivity had an IgG3/IgG4k subtype. Two (67%) patients treated with cyclical cyclophosphamide and steroids (cCYC/GC) achieved complete remission and one patient (33%) with elevated baseline creatinine had a reduction in serum creatinine with persistent proteinuria at the end of the 12th month of follow‐up. One patient with PLA2R positive MN was treated with Rituximab and is in complete remission. The patient with an elevated free light chain at baseline was treated with Bortezomib/Thalidomide/Dexamethasone, had complete remission at 12 months, however, had a progressive rise in creatinine over the next 40 months of follow‐up. The current series, though limited by numbers, documents the efficacy of conventional therapies in non‐malignant associated MN with monoclonal deposits on IF.     

Lymphoplasmacytic lymphoma causing light chain cast nephropathy

Plasma cell dyscrasias are frequently associated with kidney disease through the production of monoclonal immunoglobulin but with a diverse set of pathologic renal patterns. While almost all patients with a renal biopsy showing a cast nephropathy have myeloma, kidney involvement associated with pathological immunoglobulin light chains and lymphoma is rare. To our knowledge, this is the first report of a cast nephropathy associated with lymphoplasmacytic lymphoma. We emphasize the relation between light chain deposition and renal dysfunction in this disease with production of light chains. A therapeutic approach that decreases light chain production appears to be warranted in these patients.     

Clonal light chain restricted primary intrapulmonary nodular amyloidosis

Primary intrapulmonary nodular amyloidosis is a rare form of immunoglobulin associated amyloidosis, also falling under the alternative appellation of amyloidoma. Although amyloidomas in other organ sites may be reflective of a localized or more generalized plasma cell dyscrasia, in the context of its presentation in the lung the presumptive basis has long been held to be one of chronic inflammation. We encountered 2 patients with nodular amyloidosis in whom the pathologic examination disclosed the basis to be one of a light chain restricted clonal lymphocytic plasma cell infiltrate, although without morphologic features of coexisting pulmonary lymphoma. These 2 patients serve to underscore the potential categorization of some cases of pulmonary nodular amyloidosis as a form of low grade B cell lymphoproliferative disease.     

Kidney and liver involvement in monoclonal light chain disorders

Monoclonal light chains (LCs) are responsible for a wide spectrum of renal and hepatic diseases, that above all include amyloid light-chain (AL) amyloidosis and light chain deposition disease (LCDD). Amyloid deposits stain for Congo red on light microscopy and have fibrillar aspect on electron microscopy, whereas deposits in LCDD are positive using monotypic LCs on immunofluorescence and have a granular aspect on electron microscopy. Sometimes fibrillar and granular deposits are observed in the same organ or in different organs of the same patient. Kidney and liver involvement is a frequent finding, both in primary amyloidosis (AL amyloidosis) or in LCDD. Renal manifestations include proteinuria, nephrotic syndrome, and progressive renal failure. End-stage renal disease requiring dialysis is observed in about 20% of patients with AL amyloidosis and in 70% of patients with LCDD. The mean survival time is about 12 to 18 months in AL amyloidosis and 34 months in LCDD. The most important prognostic factor is severe cardiac involvement, which reduces the mean survival to only 6 months. Hepatic manifestations include hepatomegaly, portal hypertension, ascites, intrahepatic cholostatic jaundice, and hepatic insufficiency. The mean survival of patients with liver damage is 14 months, but it is reduced to 5 months in patients with cholostatic jaundice. Contemporary kidney and liver involvement is usually observed on histologic examination, less frequently as clinical manifestation. No specific treatment exists for AL amyloidosis and LCDD, and the prognosis remains severe. The aim of treatment is to suppress proliferation of the abnormal clone of plasma cells and remove tissue deposits. The regimens, including melphalan-prednisone (MP) or vincristine-doxorubicin-dexamethasone (VAD), are used both in AL amyloidosis or in LCDD with some effectiveness. New approaches, especially the use of 4'-iodo-4'deoxydoxorubicin, could achieve better results. Dialysis seems to not worsen the outcome in both diseases because survival of patients on dialysis is not different from that of patients not reaching uremia. Also, kidney and liver transplantation is effective, though amyloidosis or LCDD may occur in transplanted organs. The most interesting therapeutic approach is autologous-blood stem-cell transplantation, which may produce a complete remission of the plasma-cell dyscrasia and a substantial improvement of clinical manifestations related to LC deposits.     

An in vitro model of light chain deposition disease

Nodular glomerulosclerosis results from increased deposition of extracellular matrix proteins and monotypic light chains. The inability of mesangial cells to degrade abnormal levels of tenascin-C--along with the increased expression of some growth factors such as platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta)--is crucial to the pathogenesis of light chain deposition disease (LCDD). In order to study the molecular processes contributing to LCDD, we grew mesangial cells in three-dimensional matrices and incubated the cells with free light chains purified from the urine of patients with biopsy-proven LCDD, immunoglobulin-associated amyloid deposits, or myeloma cast nephropathy. Light chains of the latter two cohorts served as controls. Mesangial cells incubated with light chains from patients with LCDD show a significant increase in tenascin-C expression, centrally located within newly formed nodules, along with increased expression of PDGF and TGF-betas, compared to mesangial cells incubated with control light chains. There was less extracellular MMP-7 even though its intracellular expression is markedly increased compared to the control. Addition of active MMP-7 degraded this excess tenascin-C in vitro, a process that could be prevented by an exogenous MMP inhibitor. Our in vitro model recapitulates in vivo findings in patients with LCDD, thus allowing definition of the sequential pathologic processes associated with glomerulopathic light chain interactions with mesangial cells.     

早期轻链沉积病的诊断

目的探讨早期轻链沉积病(LCDD)的诊断方法。方法对临床怀疑LCDD,但肾活检光镜表现不特异的4例患者进行了肾组织免疫电镜的κ及λ轻链检查,并与免疫荧光、电镜结果及临床资料进行了对照分析。结果免疫电镜标记的胶体金颗粒与电镜下见到的电子致密物沉积一致;所标记的κ或λ与血、尿免疫电泳及免疫荧光结果一致,证明了LCDD的诊断。结论早期LCDD的诊断更应该强调免疫荧光及电镜检查的作用,免疫电镜检查有助于明确LCDD的诊断。     

Clinicopathological significance of light chain deposition in IgA nephropathy

Background

Clinicopathological significance of light chain deposition in IgA nephropathy and the relation of monotypic IgA deposition to bone marrow abnormalities are important issues to be clarified.

Methods

We retrospectively investigated light chain deposition in 526 patients with IgA nephropathy. We divided the patients into 5 groups according to the balance of intensity of both light chain deposition: lambda monotypic, lambda dominant, polytypic, kappa dominant and kappa monotypic. Clinicopathological parameters were compared among the groups. The relation of monotypic IgA deposition to hematological malignancy was also evaluated.

Results

The prevalence of monotypic IgA deposition was 6.3%, 33 patients (21 lambda and 12 kappa). Thirty-two (4.0%) and 10 patients (1.9%) were classified into lambda and kappa dominant groups, respectively. Polytypic IgA deposition was observed in 455 patients (85.7%). Age of onset, age at biopsy, urinary protein creatinine ratio, the percentage of global glomerulosclerosis, and the degree of IgA and C3 deposition were different among the groups. However, there was no gradual difference according to the groups. No patient with monotypic IgA deposition showed hematological abnormality at biopsy and during follow-up.

Conclusions

The prevalence of IgA monotypic deposition was extremely low. Clinicopathologically, we could not differentiate patients with monotypic IgA deposition from those with polytypic one and no hematological disorder was documented in patients with monotypic IgA deposition. Whether IgA nephropathy with monotypic IgA deposition and that with polytypic one is the same entity or not, and relation between monotypic IgA deposition and hematological malignancy should be clarified by further investigations.

     

Lambda light chain deposition disease in a renal allograft

Light chain deposition disease (LCDD) of the kidney is characterized by deposition of monoclonal light chains predominantly in glomeruli and in tubular basement membranes. The disease is frequently associated with a lymphoproliferative disorder, and the majority of cases are caused by deposition of kappa light chains. Although the occurrence of de novo multiple myeloma after renal transplantation is uncommon, there are several reports of LCDD involving renal allografts, either de novo or in patients with a diagnosis of LCDD prior to transplantation. To the best of our knowledge, all previously described cases in allografts have been in patients with kappa chain deposition. The relative importance of intrinsic properties of the kidney in predisposing to either kappa or lambda light chain deposition is not known. We present a case of LCDD caused by deposition of lambda light chains in a patient who received a cadaveric renal transplant.     

Histopathological atlas of renal diseases: light chain deposition disease

Monoclonal diseases of B-cell lineage, often referred to as plasma cell dyscrasias, are characterized by abnormal and uncontrolled proliferation of a single clone of B cells at different maturation stages, with a more or less marked differentiation to immunoglobulin (Ig)-secreting plasma cells. Thus B-cell proliferation is usually associated with the production and secretion in blood of a monoclonal Ig or a fragment thereof. An ominous consequence of secretion of monoclonal Ig products is their deposition in tissue. These proteinaceous deposits can take the form of casts (in myeloma cast nephropathy), cristals (in myeloma-associated Fanconi's syndrome), fibrils (in light-chain [LC] amyloidosis), or granular precipitates (in monoclonal Ig deposition disease [LCDD]).     

轻链沉积病肾损害的诊断与治疗

轻链沉积病(LCDD)为单克隆免疫球蛋白轻链在肾脏、心脏、肝脏等组织的沉积。LCDD肾损害起病时多伴有慢性肾功能不全。典型的LCDD肾损害有相对特殊的临床表现,血、尿蛋白电泳及游离轻链定量有助于诊断,确诊需行肾组织病理学检查,包括光镜、荧光显微镜及电镜等检查。LCDD肾损害的治疗应综合考虑B细胞增殖程度和单克隆免疫球蛋白对肾功能造成的损害。应积极控制B细胞增殖,但治疗时应选择肾毒性较小的药物如硼替佐米,必要时改用大剂量马法兰＋周围血干细胞移植(HDM/ASCT)方案。     

Calmodulin-myosin light chain kinase inhibition changes fibroblast-populated collagen lattice contraction, cell migration, focal adhesion formation, and wound contraction

Wound healing requires fibroblast migration, synthesis of new extracellular matrix, and organization of that matrix, all of which depend upon myosin ATPase activation and subsequent cytoplasmic actin-myosin contraction. Myosin ATPase activity is optimized by phosphorylation of myosin light chain at serine 19. Several different signaling pathways can perform that phosphorylation, the focus here is calcium saturated calmodulin dependent -myosin light chain kinase (CaM-MLCK). It is proposed that CaM-MLCK phosphorylation of myosin light chain and subsequent myosin ATPase activation affects granulation tissue fibroblast behavior and contributes to wound contraction. Myosin ATPase activity generates actin-myosin contraction within fibroblasts. Myosin ATPase activity is involved in ATP-induced cell contraction, the generation of focal adhesions, fibroblast migration, fibroblast populated collagen lattice (FPCL) contraction, and wound contraction. The MLCK inhibitors ML-9 and ML-7 inhibited ATP-induced cell contraction, fibroblast migration, FA formation, and FPCL contraction. The calmodulin inhibitors W7 and fluphenazine blocked rat open wound contraction. In addition, fluphenazine delayed re-epithelialization. These findings support the idea that fibroblast CaM-MLCK activity is essential for tissue repair. We speculate that inhibition of CaM-MLCK may reduce or prevent detrimental fibrotic contracture.     

Changes in serum myosin light chain I following aortocoronary bypass operations

The changes in myosin light chain I (MLC I) following aortocoronary bypass were studied in 31 patients and the curves of these changes were classified into three different patterns. A peak level of 14.7±1.54 ng/ml was seen in seven patients on postoperative day (POD) 2 which decreased suddenly to less than twice the normal value by POD 7 (group 1). Another 19 patients showed a peak level of 20.7±16.5 ng/ml on POD 5, which decreased slowly and was still high even by POD 7 (group 2). The remaining five patients developed only a slight increase in the MLC I level after the operation, with a peak value of 5.5±0.8 ng/ml (group 3). Creatine kinase myocardial band and glutamic oxaloacetic transaminase also remained low in this group. No correlation existed between the peak value of MLC I and the aortic cross-clamping time, or between the peak value of MLC I and the cardiopulmonary bypass time. Furthermore, the difference in cardiac output before and after the operation did not significantly differ among the three groups. These findings indicate that the measurement of MLC I is useful for diagnosing perioperative myocardial damage and may also be useful in the study of myocardial protection.