[Identification of transcriptional features and surface markers of plasma cell clones in POEMS syndrome by single-cell RNA sequencing].

POEMS syndrome is a rare monoclonal plasma cell disorder with unique symptoms distinct from other plasma cell neoplasms. To identify and find the transcriptional features of clonal plasma cells in POEMS syndrome (POEMS clones), single-cell RNA sequencing was performed on patient-derived bone marrow plasma cells. POEMS clones were identified in 5 out of 10 patients, and the proportions of POEMS clones in the plasma cells were markedly smaller than that of other plasma cell malignancies such as multiple myeloma and MGUS. The transcriptional features of POEMS clones differed from those of other plasma cell diseases, and representative MM-related oncogenes were not upregulated in POEMS clones. Notably, POEMS clones are negative for CD19 and express significantly lower MHC-II levels than normal plasma cells; thus, CD19- HLA-DRlo is confirmed as a useful marker to identify POEMS clones in patients. These findings unveil the unique features of POEMS clones and contribute to the understanding of the pathogenesis of POEMS syndrome.

Immunoglobulin variable domain high-throughput sequencing reveals specific novel mutational patterns in POEMS syndrome.

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare multisystem disease resulting from an underlying plasma cell (PC) dyscrasia. The pathophysiology of the disease remains unclear, but the role of the monoclonal immunoglobulin (Ig) light chain (LC) is strongly suspected because of the highly restrictive usage of 2 λ variable (V) domains (IGLV1-40 and IGLV1-44) and the general improvement of clinical manifestations after PC clone-targeted treatment. However, the diagnostic value of Ig LC sequencing, especially in the case of incomplete forms of the disease, remains to be determined. Using a sensitive high-throughput Ig repertoire sequencing on RNA (rapid amplification of cDNA ends-based repertoire sequencing [RACE-RepSeq]), we detected a λ LC monoclonal expansion in the bone marrow (BM) of 83% of patients with POEMS syndrome, including some in whom BM tests routinely performed to diagnose plasma cell dyscrasia failed to detect λ+ monoclonal PCs. Twenty-four (83%) of the 29 LC clonal sequences found were derived from the IGLV1-40 and IGLV1-44 germline genes, as well as 2 from the closely related IGLV1-36 gene, and all were associated with an IGLJ3*02 junction (J) gene, confirming the high restriction of VJ region usage in POEMS syndrome. RACE-RepSeq VJ full-length sequencing additionally revealed original mutational patterns, the strong specificity of which might crucially help establish or eliminate the diagnosis of POEMS syndrome in uncertain cases. Thus, RACE-RepSeq appears as a sensitive, rapid, and specific tool to detect low-abundance PC clones in BM and assign them to POEMS syndrome, with all the consequences for therapeutic options.

Cereblon expression is a prognostic marker in newly diagnosed POEMS syndrome treated with lenalidomide plus dexamethasone.

POEMS syndrome is a rare plasma cell disorder. Lenalidomide has recently emerged as a therapeutic option for POEMS syndrome. Cereblon has been identified as the direct target of lenalidomide, and high cereblon expression is associated with better response and outcome to lenalidomide therapy in multiple myeloma patients. Here, we analyzed the predictive value of cereblon, IKZF1, and IKZF3 in CD138+ selected plasma cells from forty-one newly diagnosed POEMS syndrome patients treated with lenalidomide in combination with dexamethasone at both gene and protein levels. We found that patients with high cereblon expression tended to achieve better hematologic response compared to those with low expression (p = 0.024 for gene expression; p = 0.01 for protein expression). Multivariate Cox regression analysis revealed high cereblon mRNA expression as an independent prognostic marker for longer progression-free survival (hazard ratio 0.542; 95% CI 0.337-0.871; p = 0.011). In conclusion, our results emphasized the role of cereblon mRNA expression as a unique biomarker for predicting the clinical response and outcome of lenalidomide-based therapy in newly diagnosed POEMS syndrome patients.

Mass cytometry identifies expansion of double positive and exhausted T cell subsets in the tumour microenvironment of patients with POEMS syndrome.

We sought to dissect the tumour microenvironment in a small cohort (N = 10) of patients with POEMS at diagnosis and after therapy using mass cytometry. We included 10 MGUS patients as controls. We identified 29 immune cell subsets in the CD45+ and CD3+ compartments. Double positive T cells and PD-1 positive CD4 T cells were expanded and naïve CD4 T cells were decreased in the bone marrow of patients with newly diagnosed/progressing POEMS. These findings provide evidence for possible antigenic-driven selection as a driver of disease pathogenesis in POEMS.

Clonal immunoglobulin λ light-chain gene rearrangements detected by next generation sequencing in POEMS syndrome.

Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome is a rare plasma cell dyscrasia characterized by polyneuropathy, organomegaly, endocrinopathy, extravascular fluid overload, M protein, and a myriad of skin changes. The pathogenesis is poorly understood, but monoclonal plasma cells are λ-restricted and these immunoglobulin λ light chain variable (IGLV) region genes are derived from only two germlines, either IGLV1-44 or 1-40. Here we analyzed the clonal IGLV gene rearrangements of genomic DNA samples of bone marrow mononuclear cells using next-generation sequencing (NGS) to understand the clonal composition of IGLV genes in patients with POEMS syndrome (n = 30). The dominant IGLV gene rearrangement of POEMS syndrome-specific germline sequences were significantly increased in 11 POEMS patients (36.7%; IGLV1-44: n = 9, IGLV1-40: n = 2). In some cases, IGLV gene rearrangement clone was not detected as significant increase but was detected using cDNA samples by heteroduplex (HD) analysis and Sanger sequencing, suggesting that the quite small number of monoclonal plasma cells may produce large quantity of mRNA of monoclonal proteins. However, significant increase of dominant clone sizes was not directly linked to the initial disease status. On the other hand, in cases with significantly increased dominant clones, they decreased and increased accompanying with disease remission and relapse. These data demonstrate that monoclonal plasma cells are related to the pathogenesis of POEMS syndrome.

Bone marrow histopathology in POEMS syndrome: a distinctive combination of plasma cell, lymphoid, and myeloid findings in 87 patients.

POEMS is an uncommon syndromic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. There are few descriptions of the bone marrow pathology of POEMS; therefore, peripheral blood smears and bone marrow aspirates and biopsies from 87 patients (143 total, 67 pretreatment, 76 posttreatment cases) with POEMS were studied. Plasma cell clonality was analyzed by flow cytometry, immunohistochemistry, and/or in situ hybridization. Monotypic plasma cells were detected in 44 pretreatment cases (66%); the majority of plasma cells expressed λ light chain (91%). The monotypic plasma cells typically were present in a background of increased polytypic plasma cells. Lymphoid aggregates were found in 33 (49%) pretreatment cases and in most cases were rimmed by plasma cells (97%). Megakaryocyte hyperplasia (36 cases) and clusters (62 cases) were frequent; however, none of the 43 cases tested had the JAK2(V617F) mutation. In summary, we have identified a novel constellation of features that should strongly suggest POEMS syndrome as part of the differential diagnosis. The constellation of λ-restricted monoclonal gammopathy, plasma cell rimming around lymphoid aggregates, and megakaryocytic hyperplasia in a bone marrow is highly suggestive of this diagnosis, especially in the context of a peripheral neuropathy.

Multiple angiogenetic factors are upregulated in POEMS syndrome.

Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome is a multisystem disorder associated with plasma cell dyscrasia. Elevated serum levels of vascular endothelial growth factor (VEGF), which strongly promotes neovascularization and vasopermeability, are considered to be responsible for the characteristic symptoms such as angiomata, pleural effusion/ascites, edema, and organomegaly in the disorder. To study whether other angiogenetic factors are upregulated in POEMS syndrome, we measured serum levels of basic fibroblast growth factor and hepatocyte growth factor (HGF), as well as VEGF, in 17 patients with POEMS syndrome. All these factors were significantly upregulated in the POEMS syndrome patients. After the treatment with anti-VEGF antibody, the levels of HGF did not change, suggesting that elevation of HGF levels is not secondary to VEGF overproduction. These results suggest that different angiogenetic factors might contribute to the pathogenesis of POEMS syndrome, and this fact might contribute to the insufficient clinical effects obtained by suppression of VEGF alone.

14q32 translocations and 13q14 deletions are common cytogenetic abnormalities in POEMS syndrome.

OBJECTIVE: POEMS syndrome is a paraneoplastic syndrome characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell (PC) proliferative disease, and skin changes. Although chromosomal aberrations have been found and extensively described for other PC disorders, whether POEMS syndrome shares similar cytogenetic profiles has been rarely reported. In this study, we aimed to clarify the cytogenetic abnormalities of patients with POEMS syndrome in our center. METHODS: Purified CD138(+) PCs from bone marrow samples of twenty patients with POEMS syndrome were studied by interphase fluorescence in situ hybridization (FISH). FISH results were analyzed for an association between cytogenetic changes and clinical features. RESULTS: A majority of patients (65%) were found to bear cytogenetic aberrations commonly seen in multiple myeloma. The 14q32 (IGH) translocation was observed in 45% of the cases and included the t(4;14) and t(11;14) translocation (15% and 25% of the cases, respectively). In addition, 25% of the patients had deletions of 13q14 and 20% had an amplification of 1q21. No significant correlation between clinical features with cytogenetic abnormalities was observed, although patients with IGH translocations were more likely to exhibit papilledema (P = 0.018). CONCLUSION: Cytogenetic aberrations in POEMS syndrome were similar to other PC dyscrasias, but at different percentages.

Characterization of immunoglobulin λ light chain variable region (IGLV) gene and its relationship with clinical features in patients with POEMS syndrome.

The M protein of POEMS syndrome is essentially λ light chain restricted. Several studies have demonstrated the restrict usage of immunoglobulin λ light chain variable region (IGLV) genes in patients with POEMS syndrome. However, these studies only included a limited number of cases, and it is not clear whether the clinical features are influenced by the IGLV gene in POEMS syndrome. Here we demonstrated that the clonal IGLV genes were strictly derived from IGLV 1-40 (11 patients, 36.7 %) and IGLV 1-44 (19, 63.3 %) gene in 30 patients with POEMS syndrome. We further evaluated the relationship between clinical features and IGLV genes. Our study showed that patients with IGLV 1-44 were older than those with IGLV 1-40, and patients with IGLV 1-40 had more severe neuropathy, hypertrichosis, and papilledema. It was suggested that the IGLV gene influenced clinical characteristics in POEMS syndrome.

Polymorphisms of F2 (G20210A), F5 (G1691A), F 7 (G10976A), F 13(G13T), FGB, ITGA2, ITGB3, PAI-I genes and its association with thrombotic complications in patients suffering from Takayasu aortoarteritis of Urals population.

OBJECTIVE: Cardiovascular complications, especially thrombotic events, are characteristic for Takayasu arteritis (TA). These events significantly deteriorate the patients' quality of life and cause disability and preterm death. Coagulation factor II (F2, G20210A), coagulation factor V (F5, G1691A, Leiden), coagulation factor VII (F7, G10976A), coagulation factor XIII (F13, G13T), fibrinogen (FGB), platelet alpha subunit of transmembrane receptor for collagens and related proteins (ITGA2), platelet glycoprotein (ITGB3), and plasminogen activator inhibitor-1 (PAI-I) gene polymorphisms coexist with TA, and their pathophysiologic interaction needs to be studied. METHODS: A total of 43 patients with TA were examined for nucleotides polymorphism in F2 (G20210A), F5 (G1691A, Leiden), F7 (G10976A), F13 (G13T), FGB, ITGA2, ITGB3, and PAI-I genes using polymerase chain reaction. Moreover, 130 sex- and age-adjusted healthy controls without a history of any thrombotic complications were enrolled. RESULTS: Among the patients with TA, there were 34 women aged between 17 and 77 (mean 49, median 49; Q1-Q3, 36-61) years and 9 men aged between 20 and 66 (mean 37.8, median 38; Q1-Q3: 31-45) years. Thrombotic complications were recorded in 22 (51%) patients with TA. Comparison of thrombophilia markers genotypes in patients with TA and healthy controls revealed homozygous and heterozygous mutation in ITGA2 (p<0.0001) and PAI-I genes (p=0.026). The frequency of occurrence of hereditary thrombophilia markers in patients with TA was assessed. Detection of the PAI-I gene mutation was significantly more frequent (p=0.032) in patients with TA with a history of thrombotic events than in those with no thrombosis history. Detection of multiple (more than 4 genes) simultaneous mutations of thrombophilia markers was significantly (p=0.0001) more frequent in patients with TA with a history of thrombotic events. CONCLUSION: Assessment of hereditary thrombophilia genetic markers reveals additional (genetic) risk markers of thrombotic complications in patients with TA and may help in decision making for antiplatelet and/or anticoagulant treatment in patients with TA to reduce the risk of thrombotic complications.

A highly heterogeneous mutational pattern in POEMS syndrome.

POEMS syndrome is a rare plasma cell dyscrasia. Little is known about its pathogenesis and genetic features. We analyzed the mutational features of purified bone marrow plasma cells from 42 patients newly diagnosed with POEMS syndrome using a two-step strategy. Whole exome sequencing of ten patients showed a total of 170 somatic mutations in exonic regions and splicing sites, with paired peripheral blood mononuclear cells as a control. Three significantly mutated genes-LILRB1 (10%), HEATR9 (20%), and FMNL2 (10%)-and eight mutated known driver genes (MYD88, NFKB2, CHD4, SH2B3, POLE, STAT3, CHD3, and CUX1) were identified. Target region sequencing of 77 genes were then analyzed to validate the mutations in an additional 32 patients. A total of 32 mutated genes were identified, and genes recurrently mutated in more than three patients included CUX1 (19%), DNAH5 (16%), USH2A (16%), KMT2D (16%), and RYR1 (12%). Driver genes of multiple myeloma (BIRC3, LRP1B, KDM6A, and ATM) and eleven genes reported in light-chain amyloidosis were also identified in target region sequencing. Notably, VEGFA mutations were detected in one patient. Our study revealed heterogeneous genomic profiles of bone marrow plasma cells in POEMS syndrome, which might share some similarity to that of other plasma cell diseases.

Genetic and transcriptional landscape of plasma cells in POEMS syndrome.

POEMS syndrome is a rare paraneoplastic disease associated with monoclonal plasma cells; however, the pathogenic importance of plasma cells remains unclear. We performed comprehensive genetic analyses of plasma cells in 20 patients with POEMS syndrome. Whole exome sequencing was performed in 11 cases and found a total of 308 somatic mutations in 285 genes. Targeted sequencing was performed in all 20 cases and identified 20 mutations in 7 recurrently mutated genes, namely KLHL6, LTB, EHD1, EML4, HEPHL1, HIPK1, and PCDH10. None of the driver gene mutations frequently found in multiple myeloma (MM) such as NRAS, KRAS, BRAF, and TP53 was detected. Copy number analysis showed chromosomal abnormalities shared with monoclonal gammopathy of undetermined significance (MGUS), suggesting a partial overlap in the early development of MGUS and POEMS syndrome. RNA sequencing revealed a transcription profile specific to POEMS syndrome when compared with normal plasma cells, MGUS and MM. Unexpectedly, disease-specific VEGFA expression was not increased in POEMS syndrome. Our study illustrates that the genetic and transcriptional profiles of plasma cells in POEMS syndrome are distinct from MM and MGUS, indicating unique function of clonal plasma cells in its pathogenesis.

A novel report of cig-FISH and cytogenetics in POEMS syndrome.

POEMS syndrome is a plasma cell proliferative disorder whose pathogenesis is poorly understood. We provide the first report of cytoplasmic immunoglobulin/FISH testing (cIg-FISH) in POEMS syndrome using established myeloma markers. We reviewed all 37 POEMS cases seen at our institution in which cIg-FISH testing had been obtained. Monosomy 13 was seen in 14 of the 37 (38%) cIg-FISH samples. One patient had trisomy 3 and 7. Three patients had IgH translocation t(11;14)(q13;q32). No abnormalities were seen at 17p13(p53). The monosomy 13 is in line with other plasma cell disorders while the low prevalence of hyperdiploidy and abnormalities at 14q32 is unique.

Rapidly Progressive Polyneuropathy in a Patient With Monoclonal Gammopathy: A Case Report of POEMS Syndrome and Beyond.

Neuropathy, the dominant clinical feature of POEMS syndrome, is typically distal, symmetric, and slowly progressive with demyelinating changes. After a gradual proximal spread, it usually results in severe muscle weakness and functional disabilities. Cases characterized by acute onset polyneuropathy are rarely described. In the present report, we describe a 32-year-old male diagnosed as POEMS syndrome, but presenting with a rapidly evolving polyneuropathy. Detailed clinical, electrophysiological, and genetic studies revealed a coexisting underdiagnosed inherited axonal neuropathy, namely Charcot-Marie-Tooth disease 2A2. The patient received lenalidomide-based chemotherapy and consolidated by autologous stem cell transplantation for his POEMS syndrome, which improved the neurological disability. In most conditions, only 1 cause is responsible for a patient's polyneuropathy. However, an insidious inherited neuropathy can be overlooked, when an acquired condition is present. The case illustrated here, to the best of our knowledge, is the first one with coexistent axonal type Charcot-Marie-Tooth disease and POEMS syndrome, suggesting that an unrecognized inherited neuropathy may change the disease course of a further acquired neuropathy.

Remarkable expression of vascular endothelial growth factor in bone marrow plasma cells of patients with POEMS syndrome.

Vascular endothelial growth factor (VEGF) is pathognomonically elevated in patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) syndrome. However, its source of overproduction is unclear. As clinical improvement is almost always associated with VEGF reduction after anti-plasma cell therapy, its increase at diagnosis has been attributed to the underlying monoclonal gammopathy, although direct evidence is still lacking. In the current study, we systemically measured VEGF levels in POEMS patients, before and after treatment. Bone marrow plasma cells showed remarkable VEGF expression, in both mRNA and protein levels, which decreased gradually in response to therapy. Of note, statistically linear correlations were observed between serum and bone marrow plasma cell VEGF levels (mRNA vs. serum, rho 0.343, p=0.003; protein vs. serum, rho 0.644, p<0.0001), supporting bone marrow plasma cells as the main source of circulating VEGF. Intriguingly, immunophenotyping revealed that bone marrow plasma cells were polyclonal in most patients at diagnosis. A clear monoclonal population, coexistent with polytypic cells, was only detectable in 11 cases (18%), in which comparable intracellular VEGF expression was observed between these two plasma cell populations (p=0.594), while monoclonal cells showed higher intracellular interleukin-6 expression (p=0.006). These patients had more serum monoclonal protein, less post-therapeutic complete remission, and inferior overall (p=0.027) and progression-free survival (p=0.002). Collectively, bone marrow plasma cells, mainly polyclonal population, are the major source of VEGF overproduction in POEMS patients.

[Autoimmune polyendocrine syndromes and related diseases: pathogenesis and clinical features]. / Autoimmun poliendokrin szindrómák es rokon kórképek: patogenezis es klinikai kép.

Autoimmune processes are involved in the pathogenesis of diseases of several endocrine organs. There are also syndromes, where autoimmune diseases of multiple endocrine and other organs occur simultaneously. The pathogenesis of certain syndromes belonging to this group has been clarified recently and this made possible the discovery of previously unknown aspects of autoimmunity. In this review the authors present a brief synopsis of the pathogenesis and clinical features of autoimmune polyendocrine syndrome type 1 and the IPEX syndrome that are inherited as monogenic traits. Although the etiology of type 2 autoimmune polyendocrine syndrome and POEMS syndrome are not as well characterized as that of the aforementioned monogenic diseases, considering their clinical importance, the authors summarize the main features of these syndromes, as well.