Follicular lymphoma immunoglobulin κ light chains are affected by the antigen selection process, but to a lesser degree than their partner heavy chains

Follicular lymphoma cells carry surface immunoglobulin whose heavy chain variable (V_H) regions exhibit considerable divergence from the aminoacid sequence predicted by the germline nucleotide sequence as a result of the somatic hypermutation process. The present study examined the extent of somatic hypermutation in follicular lymphoma κ light chain variable region (Vκ) genes about which the available data is limited. DNA extracted from fresh frozen lymph node tissue of 14 patients with follicular lymphoma at diagnosis was subjected to polymerase chain reaction (PCR) amplification aimed at detecting clonal V_H and V_L (L; light chain) gene rearrangements. Clonal Vκ gene rearrangements were detected in 10/14 cases. Amplified V_H and Vκ genes of these 10 cases were directly sequenced by the dideoxy-chain termination method. In all cases, rearranged V_H genes demonstrated numerous mutations clustering in the complementarity determining regions (CDRs), in keeping with previous reports. The degree of divergence of the rearranged Vκ genes from the closest homologous germline Vκ genes varied significantly. Furthermore, two patterns of mutations were observed: (i) in six cases (60%), mutations were most often of the replacement (R) type (changing the aminoacid sequence of the encoded polypeptide) in the CDRs and of the silent (S) type (leaving the aminoacid sequence of the encoded polypeptide unchanged) in the framework regions (FWRs) resulting in R:S ratios significantly greater than would have occurred by chance; (ii) in four cases (40%), very few or no mutations were observed and the distribution of mutations as well as the R:S mutation ratios did not differ significantly from what would have occurred by chance alone. These findings imply that, compared to their partner heavy chains, the κ light chains of follicular lymphoma neoplastic B-cells' surface immunoglobulin (sIg): (i) are less affected by somatic hypermutation; (ii) play a less significant role in the antigen selection process.     

Prognostic value of serum free light chain ratio at diagnosis in multiple myeloma

The prognostic value of baseline serum free light chain ratio (sFLCR) was investigated in 94 multiple myeloma (MM) patients. sFLCR was calculated as kappa/lambda or lambda/kappa, depending on the patients' dominating monoclonal light chain. Median baseline sFLCR was 3.57 in kappa-MM patients, 45.09 in lambda-MM. 'High' sFLCR (> or = the observed median value for kappa- and lambda-MM respectively) correlated with elevated serum creatinine and lactate dehydrogenase, extensive marrow infiltration and light chain type MM. The 5-year disease-specific survival was 82% and 30% in patients with sFLCR lower than and equal or greater than the median, respectively (P = 0.0001). sFLCR was an independent prognostic factor.     

Antibody reactivities to skeletal muscle proteins in a patient with λ light chain secreting multiple myeloma, generalised amyloidosis and rhabdomyolysis

Rhabdomyolysis is a rare complication in haematological malignancies, and a diverse range of factors has been implicated in the etiology of the syndrome. In the present study we analysed muscle morphology and antibody reactivities to skeletal muscle proteins in a patient diagnosed with lambda (lambda) light chain-secreting multiple myeloma (MM) and amyloidosis, who developed a progressive rhabdomyolysis. The muscle tissue analysis showed focal amyloid depositions and a low degree of atrophy and inflammation. Antibody reactivities against muscle proteins of approximately 42, 51 and 66 kD, respectively, were present in the patient's serum. The antibody specificities were revealed by lambda light chain- or IgM-specific antibodies. The results indicate a possible etiologic link between antibody reactivities towards muscle proteins and muscle tissue disorder in a patient with the unique combination of rhabdomyolysis, amyloidosis and MM of the light chain type.     

Signet ring-like light chain myeloma with systemic spread

The morphological presentation of malignant plasma cells in multiple myeloma (MM) varies from mature to anaplastic plasma cells with only one reported case of signet ring variant. We describe here another case of signet ring-like lambda light chain MM associated with extra-skeletal spread to lymph nodes, spleen and liver. The clinical and pathological presentations were atypical with no evidence of bone-lytic lesions or monoclonal component on protein electrophoresis, leading to a delay of several years in the diagnosis. Recognition of this morphological entity of MM may help in an early diagnosis of this rare variant.     

Redefining the prognostic likelihood of chronic lymphocytic leukaemia patients with borderline percentage of immunoglobulin variable heavy chain region mutations

In chronic lymphocytic leukaemia (CLL), caution is warranted regarding the clinical implications of immunoglobulin variable heavy chain region (IGHV) rearrangements with a ‘borderline’ (BL) percentage of mutations (i.e. 97–97·9% IGHV identity). We analysed the IGHV mutational status in 759 untreated CLL patients (cohort 1). BL-CLL (n = 36, 5%) showed a time to first treatment (TFT) similar to that of M-CLL (n = 338) and significantly longer than that of UM-CLL (n = 385), despite the enrichment in subset #2 cases. In fact, CLLs belonging to subset #2 (n = 15/759, 2%) were significantly more frequent among BL-CLLs (n = 5/36, 14%), with a brief TFT. TFT of BL-CLL remained comparable to that of M-CLL also considering the 327 CLL patients evaluated at diagnosis. These findings were then validated in an independent cohort 2 of 759 newly diagnosed CLL patients (BL-CLL: n = 11, 1·4%) and in all newly diagnosed patients from cohorts 1 and 2 (n = 1 086, 84% stage A; BL-CLL: n = 47, 4·3%). BL-CLL at diagnosis showed a biological profile comparable to that of M-CLL with a low frequency of unfavourable prognostic markers, except for a significant enrichment in subset #2. Our data suggest that the prognosis of BL-CLL is good and similar to that of M-CLL, with the exception of subset #2 cases.     

Development of rapidly progressive liver light chain deposition under VAD chemotherapy in multiple myeloma

Light chain deposition disease (LCDD) is a multisystemic disorder seen in the setting of plasma cell dyscrasias. The histological characteristic of this disorder is the deposition of a homogeneous, granular, slightly eosinophilic and non-Congophilic material that shows immunostaining for monoclonal light chains (kappa or gamma), while in primary amyloidosis (AL) the proteinaceous substance is fibrillar and Congo red positive. In contrast with AL, the light chain in LCDD is usually of the kappa-type. Renal involvement, resulting in nephrotic syndrome, is usually the prominent feature of LCDD. Patients with this disease may also have heart, liver or other organ involvement, mimicking the picture of primary systemic amyloidosis. However, liver failure has rarely been described in patients with LCDD. A patient with myeloma-associated LCDD who developed rapidly progressive liver kappa light chain deposition with fatal outcome after undergoing the first cycle of vincristine/doxorubicin/dexamethasone chemotherapy is reported.     

Heavy/light chain ratio for the assessment of minimal residual disease in myeloma patients achieving complete response

To prevent relapse, high risk paediatric acute lymphoblastic leukaemia (ALL) is treated very intensively. However, most patients who eventually relapse have standard or medium risk ALL with low minimal residual disease (MRD) levels. We analysed recurrent microdeletions and other clinical prognostic factors in a cohort of 475 uniformly treated non‐high risk precursor B‐cell ALL patients with the aim of better predicting relapse and refining risk stratification. Lower relapse‐free survival at 7 years (RFS) was associated with IKZF1 intragenic deletions (P < 0·0001); P2RY8‐CRLF2 gene fusion (P < 0·0004); Day 33 MRD>5 × 10⁻⁵ (P < 0·0001) and High National Cancer Institute (NCI) risk (P < 0·0001). We created a predictive model based on a risk score (RS) for deletions, MRD and NCI risk, extending from an RS of 0 (RS0) for patients with no unfavourable factors to RS2 +  for patients with 2 or 3 high risk factors. RS0, RS1, and RS2 +  groups had RFS of 93%, 78% and 49%, respectively, and overall survival (OS) of 99%, 91% and 71%. The RS provided greater discrimination than MRD‐based risk stratification into standard (89% RFS, 96% OS) and medium risk groups (79% RFS, 91% OS). We conclude that this RS may enable better early therapeutic stratification and thus improve cure rates for childhood ALL.     

Potential pitfalls of serum free light chain analysis to assess treatment response for multiple myeloma

Response to treatment in patients with a plasma cell disorder is typically measured by evaluating the bone marrow and myeloma markers, including monoclonal protein spike and immunofixation (IFE) in blood and urine, and serum free light chains (sFLCs). Stringent complete response criteria for Multiple Myeloma (MM) patients require a normal FLC ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence. We performed a retrospective chart review to further evaluate these criteria. A total of 142 patient charts were analysed. Of these, 17 patients were found to have an abnormal sFLC ratio, but no other evidence of disease, including normal flow cytometry and normal fluorescence in situ hybridization (FISH) analysis on highly selected plasma cells. In all patients, the abnormal sFLC ratio was caused by abnormalities in the serum kappa light chains. These results suggest that current definitions may need to be revised to take aberrancies related to abnormal immune recovery into account.     

Increased serum levels of β2m-free HLA class I heavy chain in multiple myeloma

Serum levels of beta2-microglobulin (beta2m)-free HLA class I heavy chain (FHC) in 94 patients with multiple myeloma (MM) were higher than in 29 patients with monoclonal gammopathy of undetermined significance (MGUS) (P = 0.023) and in 97 sex- and age-matched healthy controls (P < 0.0001). Spearman correlation analysis indicated that in MM, FHC correlated with beta2m (r = 0.31, P = 0. 003) and the percentage of bone marrow plasma cells (BMPC%) (r = 0. 36, P = 0.002), whereas beta2m, in addition to BMPC% (r = 0.43, P = 0.0003), also correlated with creatinine levels (r = 0.63, P < 0.0001), haemoglobin levels (r = -0.35, P = 0.0007) and patient age (r = 0.34, P < 0.0011). Furthermore, MM patients with poor prognosis (beta2m >/= 6 mg/l) displayed higher FHC levels than those with a better prognosis (beta2m < 6mg/l) (P < 0.021). At variance from beta2m, these levels were not influenced by renal failure, as indicated by the lack of Spearman correlation of FHC with creatinine concentration and of statistical significance between the median FHC concentration of MM patients with creatinine < 176.6 micromol/l and those with creatinine >/= 176.6 micromol/l (P = 0.3). Stratification of patients according to disease activity and stage showed that FHC levels were only statistically different (P = 0.04) for disease activity, whereas beta2m and C-reactive protein were not. Taken together, our data indicate that serum FHC may be a useful disease marker in MM.     

Multiple myeloma: light chain isotype suppression--a marker of stable disease at presentation

Prognosis in multiple myeloma (MM) is related to the establishment of an immunologically and kinetically characteristic plateau phase. Patients who present with this state may not benefit from immediate chemotherapy. We assessed 20 patients with MM who were staged according to the Salmon and Durie classification at diagnosis and monitored throughout the course of their disease. Patients with a lambda paraprotein and a kappa/lambda lymphocyte ratio in the blood greater than 4.0 were considered to demonstrate light chain isotype suppression (LCIS). Similarly, patients with a kappa paraprotein and a kappa/lambda ratio of less than 0.55 were also considered to have LCIS (1). 14 patients had LCIS; of these, 6 were classified as stage IA, 2 as stage IB, 3 as stage IIA, and 3 as stage IIIA. 6 patients did not have LCIS; 3 were classified as stage IIA, 1 as stage IIIA and 2 as stage IIIB. 10 patients with LCIS were assessed for treatment benefit following administration of melphalan and prednisone, as defined by a fall in the serum paraprotein level of greater than 50% over 6 months. In 8 patients the serum paraprotein levels did not fall, and the patients remained in good health without clinical deterioration. Thus LCIS at presentation may indicate patients in whom treatment can be safely deferred or in whom aggressive therapy is not indicated.     

Light-heavy chain deposition disease progressing to multiple myeloma

Light chain deposition disease (LCDD) and light and heavy chain deposition disease (LHCDD) are rare clinical entities that have been associated with multiple myeloma, with monoclonal gammopathy of unknown significance (MGUS), or without any detectable protein abnormality. Renal failure is common, the diagnosis is difficult and prolonged survival is rare. The first patient with LHCDD and MGUS who progressed to multiple myeloma after 11 years is presented. A rising level of monoclonal IgA immunoglobulin, bone marrow plasmacytosis, and the presence of multiple bone marrow lesions on magnetic resonance imaging provided the first evidence of disease evolution. When management of serious complications permits a long survival, some patients with LCDD or LHCDD will develop multiple myeloma.     

Multiple myeloma shows no intra-disease clustering of immunoglobulin heavy chain genes

Background

Characterization of the immunoglobulin gene repertoire has improved our understanding of the immunopathogenesis of lymphoid tumors. Early B-lymphocyte precursors of multiple myeloma are known to exist and might be susceptible to antigenic drive.

Design and Methods

To verify this hypothesis, we collected a database of 345 fully readable multiple myeloma immunoglobulin sequences. We characterized the immunoglobulin repertoire, analyzed the somatic hypermutation load, and investigated for stereotyped receptor clusters.

Results

Compared to the normal immunoglobulin repertoire, multiple myeloma displayed only modest differences involving only a few genes, showing that the myeloma immunoglobulin repertoire is the least skewed among mature B-cell tumors. Median somatic hypermutation load was 7.8%; median length of complementarity determining-region 3 was 15.5 amino acids. Clustering analysis showed the absence of myeloma specific clusters and no similarity with published chronic lymphocytic leukemia or lymphoma subsets.

Conclusions

Analysis of multiple myeloma immunoglobulin repertoire does not support a pathogenetic role for antigen selection in this tumor.     

The prognostic value of diagnosing concurrent multiple myeloma in immunoglobulin light chain amyloidosis

The prevalence and prognostic value of a concomitant diagnosis of symptomatic or asymptomatic multiple myeloma (MM), as defined by the current International Myeloma Working Group (IMWG) criteria, in patients with immunoglobulin light chain amyloidosis (AL), are unknown. We studied 46 consecutive patients with AL who underwent quantification of serum M‐protein and clonal bone marrow plasma cells, as well as a comprehensive evaluation for end organ damage by MM. Using standard morphology and CD138 immunohistochemical staining, 57% and 80% of patients were found to have concomitant MM, respectively. Nine patients exhibited end organ damage consistent with a diagnosis of symptomatic MM. While overall survival was similar between AL patients with or without concurrent myeloma (1‐year overall survival 68% vs. 87%; P = 0·27), a diagnosis of symptomatic myeloma was associated with inferior outcome (1‐year overall survival 39% vs. 81%; P = 0·005). Quantification of bone marrow plasma cells by both standard morphology and CD138 immunohistochemistry identified a much higher prevalence of concurrent MM in patients with AL than previously reported. Evaluation of bone marrow plasma cell infiltration and presence of myeloma associated end organ damage could be clinically useful for prognostication of patients with AL.     

轻链型多发性骨髓瘤一例

患者,女性,61岁。因反复头昏,乏力,加重2个月入院。一年前,患者无明显诱因感头昏、乏力,伴活动后心悸,当时未行诊治。2个月前患者因受凉后出现咳嗽、咳痰,并发热,自服感冒药症状无缓解。且头昏、乏力加重,上一层楼即感心悸不适。查体:中度贫血貌,胸骨压痛,浅表淋巴结肿大,心肺(-),肝脾不大。实验室检查:Ｈｂ71ｇ/Ｌ,尿蛋白(),尿本周氏蛋白阳性;ＷＢＣ4.8×109/Ｌ,ＢＰＣ73×1012/Ｌ;ＩｇＧ6.14ｇ/Ｌ(8.00～15.50ｇ/Ｌ),ＩｇＡ0.16ｇ/Ｌ(0.74～2.86ｇ/Ｌ),ＩｇＭ0.21ｇ/Ｌ(0.62～2.26ｇ/Ｌ);抗λ血清和尿之间均出现一条明显沉淀线;尿素4.63ｍ…