Immunoglobulin repertoire sequencing and de novo sequencing - Powerful tools for identifying free light chains from patients with light chain cast nephropathy.

In patients with light chain cast nephropathy (LCCN), abundantly produced monoclonal immunoglobulin free light chains (FLCs) play a vital role in pathogenesis. Determining the precise sequences of patient-derived FLCs is therefore highly desirable. Although immunoglobulin repertoire sequencing (5' RACE-seq) has been proven to be sensitive enough to provide full-length V(D)J region (variable, diversity and joining genes) of FLCs using bone marrow samples, an invasive and bone marrow independent method is still in demand. Here a de novo sequencing workflow based on the bottom-up proteomics for patient-derived FLCs was established. PEAKS software was used for the de novo sequencing of peptides that were further assembled into full-length FLC sequences. This de novo protein sequencing method can obtain the full-length amino acid sequences of FLCs, and had been shown to be as reliable as 5' RACE-seq. The two LCCN sequences derived from above the two methods were identical, and they possessed more hydrophobic or nonpolar amino acids compared with the corresponding germline, which may be associated with the pathogenesis.

Proteinase­3­antineutrophil cytoplasmic antibody­associated vasculitis secondary to subacute infective endocarditis: A case report.

A 58-year-old male patient was admitted to Peking University First Hospital (Beijing, China) due to recurrent hematuria, proteinuria and kidney dysfunction. The patient was positive for proteinase-3 (PR3)-antineutrophil cytoplasmic antibody (ANCA). Pathology of the kidney showed focal proliferative necrotizing glomerulonephritis with crescent formation and immune complex-mediated glomerulonephritis. The patient was diagnosed with PR3-ANCA-associated vasculitis (AAV), received intensive immunosuppressive therapy and experienced two relapses within 1 year. After admission, aortic valve vegetation was observed via echocardiography. The patient subsequently received antibiotic treatment and valve replacement, and achieved complete remission of kidney and cardiac function. The present case emphasized the importance of identifying secondary reasons for ANCA formation, especially infective endocarditis in patients with PR3-AAV.

Light-chain proximal tubulopathy: a retrospective study from a single Chinese nephrology referral center.

Background: Light-chain proximal tubulopathy (LCPT) is a rare disease characterized by the accumulation of monoclonal light chains within proximal tubular cells. This study aimed to investigate the clinical characteristics of LCPT from a single Chinese nephrology referral center.Methods: Patients with kidney biopsy-proven isolated LCPT between 2016 and 2022 at Peking University First Hospital were retrospectively included. Clinical data, kidney pathological type, treatment, and prognosis were analyzed.Results: Nineteen patients were enrolled, the mean age at diagnosis was 57 ± 11 and the sex ratio was 6/13 (female/male). Mean proteinuria was 2.44 ± 1.89 g/24 hr and the mean estimated glomerular filtration rate (eGFR) at the point of biopsy was 59.640 ± 27.449 ml/min/1.73 m2. κ-restriction (84%) was dominant among LCPTs. An abnormal free light chain ratio was observed in 86% of the patients. Proximal tubulopathy with cytoplasmic inclusions accounted for the majority (53%), followed by tubulopathy associated with interstitial inflammation reaction (26%), proximal tubulopathy without cytoplasmic inclusions (16%), and proximal tubulopathy with lysosomal indigestion/constipation (5%). One patient presented with acute kidney injury and 16 patients presented with chronic kidney disease. Regarding follow-up, patients received bortezomib-based or R-CHOP chemotherapy or supportive treatment only. The mean follow-up time was 22 ± 16 months, and the mean eGFR was 63.098 ± 27.439 ml/min/1.73 m2 at the end of follow-up. These patients showed improved or stable kidney function.Conclusions: This is the first case series report of LCPT in four different pathological types in northern China. Clone-targeted chemotherapy may help preserve the kidney function in these patients.

Fatal Case of Pneumocystis Jirovecii Pneumonia (PJP) During Treatment for Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) Syndrome.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is an acute, rare and potentially fatal drug reaction. To date, limited studies have reported secondary Pneumocystis jirovecii pneumonia (PJP) infection during the treatment of DRESS syndrome. A 53-year-old man was admitted to the hospital due to a persistent fever lasting for 5 days. He had a medical history of hypertension, psoriasis, urticaria, and had recently been treated with carbamazepine for nerve spasm two weeks ago. After admission, the patient presented with a high fever accompanied by chills, abdominal pain, bilateral upper limb muscle pain, and generalized lymph nodes enlargement. Laboratory tests revealed elevated eosinophils and atypical lymphocytes. Subsequently, the patient developed multiple internal organ complications, including oliguria, elevated serum creatinine, liver enzymes, and cardiac troponin I. Based on diagnostic criteria, the patient was diagnosed with DRESS syndrome. To manage the DRESS syndrome, the patient was successively or simultaneously prescribed methylprednisolone, cyclosporin and intravenous immunoglobulin, resulting in an improvement of the condition. However, during the treatment, the patient was infected with Pneumocystis jirovecii. Despite targeted therapy with trimethoprim/sulfamethoxazole, primaquine and clindamycin successively, no remission was observed. Chest CT scans exhibited multiple exudations in both lungs, indicative of interstitial pneumonia. Unfortunately, the patient's oxygenation progressively declined, leading to his untimely demise. This rare case further highlights the need for clinicians to be aware of the risk of Pneumocystis jirovecii infection in DRESS syndrome patients treated with long-term and high-dose glucocorticoid therapy.

Characteristics of Complement Protein Deposition in Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposition.

BACKGROUND: Hypocomplementemia and complement co-deposition with monoclonal immunoglobulins in glomeruli are not rare in proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID). Deposition of monoclonal immunoglobulins in glomeruli has been suggested to activate complement and cause kidney injury. However, the profiles of complement activation in PGNMID and their clinical and pathologic significance need to be clarified. METHODS: Forty-six patients with PGNMID were enrolled. Proteomic analysis of glomeruli using laser microdissection and mass spectrometry was performed for ten patients with PGNMID to determine the composition of glomerular deposits. Kidney deposition of complement components was detected by immunohistochemistry and immunofluorescence. Urinary and plasma levels of complement components were measured by an enzyme-linked immunosorbent assay. Group differences were assessed using t tests or Mann-Whitney U tests depending on the distribution. Correlation analysis was performed using Spearman rank correlation or Pearson correlation. RESULTS: Laser microdissection and mass spectrometry-based proteomic analysis showed that complement components were the most enriched proteins deposited in the glomeruli of patients with PGNMID. Glomerular deposition of C3c, C4d, and C5b-9 was detected in most patients. Levels of urinary and plasma C3a, C5a, soluble C5b-9, C4d, Bb, and C1q as well as urinary mannose-binding lectin were significantly higher in patients with PGNMID compared with healthy controls. The intensity of C3c and C4d deposition in glomeruli correlated with serum creatinine and the percentage of crescents, respectively. Furthermore, levels of urinary complement components correlated positively with serum creatinine, urinary protein excretion, percentage of crescents, and global glomerulosclerosis in kidney biopsies, whereas plasma levels of most complement components did not show a significant correlation with clinicopathologic parameters. In multivariable analysis, a higher level of urinary C4d was identified as an independent risk factor of kidney failure. CONCLUSIONS: The complement system was found to be overactivated in PGNMID, and levels of urinary complements correlated with disease severity. A higher level of urinary C4d was identified as an independent risk factor of kidney failure.

Clinicopathological and immunological features of new onset kidney disease: a rare event after SARS-CoV-2 vaccination.

The onset of various kidney diseases has been reported after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. However, detailed clinical and pathological features are lacking. We screened and analyzed patients with newly diagnosed kidney diseases after inactivated SARS-CoV-2 vaccination in Peking University First Hospital from January 2021 to August 2021, and compared them with the reported cases in the literature. We obtained samples of blood, urine and renal biopsy tissues. Clinical and laboratory information, as well as light microscopy, immunostaining and ultrastructural observations, were described. The SARS-CoV-2 spike protein and nucleoprotein were stained using the immunofluorescence technique in the kidney biopsy samples. SARS-CoV-2 specific antibodies were tested using magnetic particle chemiluminescence immunoassay. The study group included 17 patients with a range of conditions including immune-complex-mediated kidney diseases (IgA nephropathy, membranous nephropathy and lupus nephritis), podocytopathy (minimal change disease and focal segmental glomerulosclerosis) and others (antineutrophil-cytoplasmic-antibody-associated vasculitis, anti-glomerular basement membrane nephritis, acute tubulointerstitial nephritis and thrombotic microangiopathy). Seven patients (41.18%) developed renal disease after the first dose and ten (58.82%) after the second dose. The kidney disease spectrum as well as clinicopathological features are similar across different types of SARS-CoV-2 vaccines. We found no definitive evidence of SARS-CoV-2 spike protein or nucleoprotein deposition in the kidney biopsy samples. Seropositive markers implicated abnormal immune responses in predisposed individuals. Treatment and follow-up (median = 86 days) showed that biopsy diagnosis informed treatment and prognosis in all patients. In conclusion, we observed various kidney diseases following SARS-CoV-2 vaccine administration, which show a high consistency across different types of SARS-CoV-2 vaccines. Our findings provide evidence against direct vaccine protein deposition as the major pathomechanism, but implicate abnormal immune responses in predisposed individuals. These findings expand our understanding of SARS-CoV-2 vaccine renal safety.

Primary membranous nephropathy in two siblings with one combined with anti-glomerular basement membrane disease: a case report.

BACKGROUND: The phospholipase A2 receptor (PLA2R) associated with membranous nephropathy (MN) is an organ-specific autoimmune disease associated with PLA2R and human leukocyte antigen (HLA) genes. Familial PLA2R-related MN is rarely reported. The combination of anti-GBM disease and MN has been well documented, though the mechanism behind it remains unclear. CASE PRESENTATION: We describe two siblings diagnosed with pathology-confirmed PLA2R-related MN 1 year apart. And one of the two siblings developed an anti-GBM disease. The high-resolution HLA typing showed identical alleles in both siblings, specifically heterozygotes of DRB1*15:01/*03:01. CONCLUSION: We describe a familial case of PLA2R-related MN supporting the role of genetic factors that HLA-DRB1*15:01 and DRB1*03:01 predispose patients in the development of PLA2R-related MN in the Han Chinese population. The combination of MN and anti-GBM disease may also partially be associated with the same susceptible HLA allele DRB1*15:01.

Clinical characteristics and prognosis of a Chinese cohort with systemic light chain amyloidosis: a single-center study.

Light chain amyloidosis is a plasma cell dyscrasia characterized by deposition of misfolded amyloid fibrils in tissues, leading to multi-organ dysfunction. We retrospectively analyzed 335 patients (median age, 60 years) with systemic light chain amyloidosis in the First Hospital of Peking University from 2011 to 2021. Involved organs were the kidney (92.8%), heart (57.9%), liver (12.8%) and peripheral nervous system (6.3%). Chemotherapy was administered to 55.8% (187/335) of patients, among whom 94.7% received novel agent-based regimens. Hematologic response (≥ very good partial response) was achieved in 63.4% of patients who received chemotherapy. Only 18.2% of patients received autologous hematopoietic stem cell transplant (ASCT). Among transplant-eligible patients, the overall survival of ASCT recipients was better than those who received chemotherapy only. The median overall survival of the patients with light chain amyloidosis was 77.5 months. Estimated glomerular filtration rate and Mayo 2012 stage were independent prognostic factors for overall survival in multivariate analysis. Although the younger age and high ratio of renal involvement might contribute to the favorable prognosis of this cohort, the role of novel agents and ASCT is also discernible. This study will provide a comprehensive perspective on progress in treatment of light chain amyloidosis in China.

Daratumumab plus bortezomib, cyclophosphamide, and dexamethasone in Asian patients with newly diagnosed AL amyloidosis: subgroup analysis of ANDROMEDA.

Subcutaneous daratumumab plus bortezomib/cyclophosphamide/dexamethasone (VCd; D-VCd) improved outcomes versus VCd for patients with newly diagnosed immunoglobulin light-chain (AL) amyloidosis in the phase 3 ANDROMEDA study. We report a subgroup analysis of Asian patients (Japan; Korea; China) from ANDROMEDA. Among 388 randomized patients, 60 were Asian (D-VCd, n = 29; VCd, n = 31). At a median follow-up of 11.4 months, the overall hematologic complete response rate was higher for D-VCd versus VCd (58.6% vs. 9.7%; odds ratio, 13.2; 95% confidence interval [CI], 3.3-53.7; P < 0.0001). Six-month cardiac and renal response rates were higher with D-VCd versus VCd (cardiac, 46.7% vs. 4.8%; P = 0.0036; renal, 57.1% vs. 37.5%; P = 0.4684). Major organ deterioration progression-free survival (MOD-PFS) and major organ deterioration event-free survival (MOD-EFS) were improved with D-VCd versus VCd (MOD-PFS: hazard ratio [HR], 0.21; 95% CI, 0.06-0.75; P = 0.0079; MOD-EFS: HR, 0.16; 95% CI, 0.05-0.54; P = 0.0007). Twelve deaths occurred (D-VCd, n = 3; VCd, n = 9). Twenty-two patients had baseline serologies indicating prior hepatitis B virus (HBV) exposure; no patient experienced HBV reactivation. Although grade 3/4 cytopenia rates were higher than in the global safety population, the safety profile of D-VCd in Asian patients was generally consistent with the global study population, regardless of body weight. These results support D-VCd use in Asian patients with newly diagnosed AL amyloidosis. ClinicalTrials.gov Identifier: NCT03201965.

A pedigree with COL4A5 mutation presenting with Alport syndrome and focal segmental glomerulosclerosis lesions: a case report.

Alport syndrome (AS) is a heterogeneous hereditary nephropathy which can be caused by the COL4A3/COL4A4/COL4A5 gene. Patients with AS present with many phenotypes associated with kidney defects, and commonly develop secondary focal segmental glomerulosclerosis (FSGS) late in the course of AS. Evidence supports the pathogenic role of COL4A3/COL4A4/COL4A5 mutations in FSGS. We report a familial hematuria pedigree with two members that have AS and FSGS, respectively. The proband presented with microhematuria, proteinuria, renal dysfunction and sensorineural hearing loss. Pathological examination of his renal biopsy samples revealed FSGS lesions and massive foam cells by light microscopy, irregular GBM, and focal podocyte foot process effacement under electron microscopy, as well as negative α5 (IV) staining by immunofluorescence detection so he was diagnosed as AS. The proband's younger brother had only renal manifestations without obvious extrarenal lesions. Light microscopy examination of renal biopsy samples showed only FSGS lesion without foam cells. Electron microscopy and α5 (IV) staining were not performed and he was diagnosed with FSGS. Using whole-exome sequencing, we identified a novel COL4A5 mutation (c.4456G>A:p.G1486S) in this pedigree, which affected two males (the proband and his brother) and three female family members. The three female family members were heterozygous or the COL4A5 mutation and only presented with microhematuria. Our findings suggest importance of electron microscopy analysis and COL4A3/COL4A4/COL4A5 mutation screening in patients with FSGS lesions under light microscopy.

Clinicopathological Spectrum of Cryoglobulinemic Glomerulonephritis without Evidence of Autoimmunity Disorders: A Retrospective Study from a Single Institute of China.

Background: Cryoglobulinemic glomerulonephritis (Cryo-GN), caused by circulating cryoglobulins, has varied etiology and clinical-pathologic manifestations. This study aimed to investigate the clinicopathological spectrum and outcome of patients with various Cryo-GN in China. Methods: A retrospective review of 74 Chinese patients with biopsy-proven cryoglobulin-related renal lesions in Peking University First Hospital from 2010 to 2020 was performed. Results: The mean age at diagnosis was 52.9 ± 15.0 years, and the female-to-male ratio was about 2/5. For the etiology screening, serum/urine monoclonal immunoglobulin could be detected on immunofixation electrophoresis in 34% of patients, including 6 patients who had hematological malignancies. Fifty-seven percent of patients had HBV infection, far more than HCV infection (5%). Ten percent of patients had other infections, and 27% of patients were classified as essential or idiopathic. Eleven out of the 15 patients with type II cryoglobulinemia had a consistent monotype of serum monoclonal immunoglobulins and monoclonal cryoprecipitate. The clinical manifestations were similar between various types of cryoglobulinemia. Hematuria, proteinuria, hypertension, anemia, and chronic renal insufficiency were the most common features. Fifty-three percent of patients presented with nephrotic syndrome, and 32% experienced acute kidney injury. Hypocomplementemia, serum-positive rheumatoid factor activity, and skin lesions were reported in 45%, 29%, and 28% of patients, respectively. After a median of 24 months follow-up, 18 patients reached end-stage kidney disease. The clone-targeted treatment could retard the renal deterioration compared with immunosuppressive therapy. Conclusions: This was the largest single-center, clinicopathological retrospective study of Cryo-GN in China. Our data strongly support the association between monoclonal gammopathy and type II Cryo-GN. The renal responsive rate of immunosuppressant therapy is still suboptimal. The clone-targeted treatment shows promising effects in patients with type I or II Cryo-GN.

Fibrinogen A Alpha-Chain Amyloidosis in Two Chinese Patients.

Objectives: Fibrinogen A alpha-chain amyloidosis (AFib amyloidosis) is the most common form of hereditary renal amyloidosis in the United Kingdom and Europe, but has rarely been reported in Asia. In this study, we reported two AFib amyloidosis patients in China, reviewing the literature and summarizing main characteristics of AFib amyloidosis in Asia. Methods: Two unrelated Chinese patients were diagnosed with AFib amyloidosis by clinical presentation, renal biopsy, mass spectrometry and DNA sequencing in Peking University First Hospital of China from 2014 to 2016. Results: Both of the patients presented with proteinuria, edema and hypertension. Renal biopsies of two patients showed extensive amyloid deposits (Congo red positive) in glomeruli, and focal tubulointerstitial amyloid deposits was also found in patient 1. Besides, hepatic involvement of amyloidosis has been detected by liver biopsy in patient 1. By electron microscopy, randomly arranged fibrils in a diameter of 8-12 nm was identified in mesangial matrix and subendothelial area of glomeruli. Immunohistochemistry demonstrated amyloid deposits were strongly positive for fibrinogen Aα in glomeruli and positive for LECT2 in the interstitium of renal medulla and the liver in Patient 1. Unevenly positive staining for both fibrinogen Aα and ApoA-I were found in Patient 2. Fibrinogen Aα was the most abundant amyloidogenic protein in both patients identified by laser microdissection and mass spectrometry-based proteomic analysis. Genetic analysis revealed the fibrinogen A a-chain gene (FGA) mutation in both patients, including a new deletion mutation [c.1639delA (p.Arg547Glyfs*21; NM_000508)] in Patient 2. Genetic analysis of the LECT2 gene in patient 1 revealed a codon change from ATC to GTC at position 172 [c.172A>G (p.Ile58Val; NM_002302)], which is a common polymorphism (SNP rs31517) in all ALECT2 amyloidosis patients. Conclusions: We reported two AFib amyloidosis patients in China, one of them coexisted with ALECT2 amyloidosis simultaneously.

Proliferative glomerulonephritis with monoclonal immunoglobulin deposits: an entity associated with distinct diseases and comparison between IgG1 and IgG3 subtypes.

OBJECTIVES: The aim of the study was to investigate the clinicopathological characteristics and prognosis of proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) and determine the differences between PGNMID associated with extrarenal disease and without clear etiology as well as the differences between IgG1 and IgG3 subtypes. METHODS: Data from 46 patients with PGNMID observed from January 2014 to September 2021 in Peking University First Hospital were retrospectively analyzed, including 36 patients without clear etiology (Group A) and 10 patients with extrarenal disease (Group B). RESULTS: At presentation patients showed proteinuria (95.7%), hematuria (89.1%), renal insufficiency (73.9%), and hypocomplementemia of C3 or C4 (35.6%). Monoclonal immunoglobulin or cell clones were detected in 22.2% of patients (10/45). The monoclonal immunoglobulins deposited in kidney were IgG3 in 40 patients, IgG1 in 5, and IgM in one. Monoclonal IgG1 deposits were more common in Group B than in Group A (4/10 vs. 1/36, p = 0.006). The intensity of glomerular C3 deposition and the frequency of subendothelial deposits in IgG3 subtype were significantly higher than those in IgG1 subtype. During a median follow-up time of 12.2 (range 1-61) months, a higher level of serum creatinine at biopsy and a higher percentage of global glomerulosclerosis were independent predictors of end-stage kidney disease. CONCLUSIONS: PGNMID associated with extrarenal disease was more likely to have monoclonal IgG1 deposits. PGNMID of IgG3 subtype differs from IgG1 subtype by higher intensity of glomerular C3 deposition and higher frequency of subendothelial deposits. Serum creatinine and global glomerulosclerosis were independent prognostic predictors of ESKD in PGNMID.

Kidney Histopathologic Spectrum and Clinical Indicators Associated with MGRS.

BACKGROUND AND OBJECTIVES: Patients with monoclonal gammopathy and concomitant kidney diseases are frequently found in clinical practice. Some of them are diagnosed with monoclonal gammopathy of renal significance (MGRS) due to the presence of monoclonal Ig-related kidney injuries. This study aimed to investigate the histopathologic spectrum and clinical characteristics associated with MGRS in a large cohort of patients with monoclonal gammopathy and biopsy-proven kidney diseases from a single Chinese nephrology referral center. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients who presented with monoclonal gammopathy (monoclonal spike on serum and/or urine immunofixation tests) and underwent kidney biopsy in the Peking University First Hospital from January 1, 1999 to December 31, 2020 were enrolled in this retrospective study. Patients with malignant hematologic diseases were excluded. Clinical and laboratory data were collected from the electronic medical record system. Comparisons of patients with and without MGRS and with and without amyloidosis were performed. The clinical characteristics associated with MGRS were identified using multivariable logistic regression. RESULTS: A total of 700 patients with monoclonal gammopathy and kidney biopsy were identified. Thirteen patients with repeat kidney biopsies were analyzed separately. For the remaining 687 patients with one kidney biopsy, 261 patients (38%) had MGRS lesions, and the rest (426 patients, 62%) had non-MGRS kidney diseases. Ig-related amyloidosis accounted for the most MGRS cases (n=164, 63%), followed by monoclonal Ig deposition disease (n=23, 9%) and thrombotic microangiopathy (n=22, 8%). In the non-MGRS group, membranous nephropathy was the most common diagnosis (n=171, 40%). In the multivariable logistic regression model, the presence of abnormal serum free light chain ratio, older age, and greater proteinuria were independently associated with MGRS. CONCLUSIONS: Monoclonal Ig amyloidosis is the leading cause of MGRS in Chinese patients with monoclonal gammopathy. The presence of abnormal free light chain ratio, older age, and greater proteinuria were associated with MGRS.

Case Report: A Rare Case of Lupus Nephritis Associated With Mantle Cell Lymphoma.

In this research, we described a very rare case of secondary lupus nephritis associated with B-cell lymphoma. An 84-year-old man was hospitalized at our institute for lower extremity edema persisting for over 2 months. He was diagnosed with systemic lupus erythematosus based on clinical and laboratory criteria, which showed impaired renal function and nephrotic syndrome with predominant hematuria. Renal biopsy showed IV+V lupus nephritis with highly infiltrated lymphoid cells in the kidney. Secondary lupus nephritis was suspected based on the possible pathogenesis of glomerular injury due to mantle cell lymphoma. Low-dose dexamethasone, rituximab, and lenalidomide were immediately started on the patient, and his renal function was improved after the first cycle of chemotherapy.

Case Report: Lenalidomide as a Second-Line Treatment for Bortezomib-Ineffective Nephrotic Syndrome Caused by LCDD: 2 Case Reports and a Literature Review.

Background: Light-chain deposition disease (LCDD) is a rare systemic disorder characterized by the deposition of monoclonal light chains in organs. The kidney is a prominent target of light-chain deposition, with a median time to end-stage renal disease (ESRD) of 2.7 years and 5-year ESRD-free survival of 37%. The therapeutic management of LCDD remains ill-defined. In addition to bortezomib-based therapy as first-line therapy, the effect of lenalidomide on LCDD is rarely reported. Case Presentation: This study describes two male LCDD patients in their 60s with nephrotic syndrome and moderately impaired renal function. One patient had monoclonal IgGλ with underlying MGRS, and another had monoclonal IgGκ with underlying monoclonal gammopathy that developed into symptomatic MM during follow-up. The hallmarks of this disease were consistent with previous reports. Both patients initially received BCD therapy, but no hematological response was observed. Consequently, the nephrotic syndrome was refractory. Sequential Rd therapy was initiated, and partial hematological response and nephrotic remission were observed in the IgGλ patient but absent in the IgGκ patient. Conclusion: Limited reports have demonstrated the effect of lenalidomide in LCDD. We report the outcome of lenalidomide in two cases of bortezomib-resistant LCDD. This treatment might be a beneficial supplement for those unresponsive or intolerant to bortezomib in LCDD, but the effect should be prospectively investigated.