Dealing With High-Risk AL Amyloidosis Patients: A Single Hematologic Center Experience.

PURPOSE: To assess the feasibility and the results of Bortezomib-based treatment of "high-risk" AL-amyloidosis patients in a hematology ward. METHODS: We report on 52 high-risk amyloidosis patients treated with first-line bortezomib-based chemotherapy. RESULTS: At day 30 from the beginning of the therapy, 23 patients (44%) achieved a hematological response (complete response plus very good partial response); 14 patients (27%) achieved a partial response; 15 patients (29%) were non-responders. After a median follow-up of 28.5 months, the survival rates were 18/23 (78%) for responders; 9/14 (64%) for partial responders and 3/15 (20%) for nonresponders with a median overall survival of 43, 24 and 11 months, respectively (log-rank test: P < .001). NHYA class I-II, NTproBNP < 6500 ng/L, the hematologic response, and the partial hematological response at day 30 independently predicted the survival. There has been no significant difference (P = .173) in survival between revised Mayo stage III and IV patients although there was a trend toward a better prognosis for Mayo stage III. A suboptimal hematological response at day 30 allowed a later organ response in 12/14 patients (85%) even without therapy change and no modification of the hematological status. CONCLUSIONS: These results show that high-risk AL-amyloidosis patients can be managed safely and effectively in a hematology ward. A partial hematologic response may herald a later better response, organ response, and can allow a subsequent second-line therapy and a good survival.

The small GTPase RhoU lays downstream of JAK/STAT signaling and mediates cell migration in multiple myeloma.

Multiple myeloma is a post-germinal center B-cell neoplasm, characterized by the proliferation of malignant bone marrow plasma cells, whose survival and proliferation is sustained by growth factors and cytokines present in the bone marrow microenvironment. Among them, IL-6 triggers the signal downstream of its receptor, leading to the activation of the JAK/STAT pathway. The atypical GTPase RhoU lays downstream of STAT3 transcription factor and could be responsible for mediating its effects on cytoskeleton dynamics. Here we demonstrate that RHOU is heterogeneously expressed in primary multiple myeloma cells and significantly modulated with disease progression. At the mRNA level, RHOU expression in myeloma patients correlated with the expression of STAT3 and its targets MIR21 and SOCS3. Also, IL-6 stimulation of human myeloma cell lines up-regulated RHOU through STAT3 activation. On the other hand, RhoU silencing led to a decrease in cell migration with the accumulation of actin stress fibers, together with a decrease in cyclin D2 expression and in cell cycle progression. Furthermore, we found that even though lenalidomide positively regulated RhoU expression leading to higher cell migration rates, it actually led to cell cycle arrest probably through a p21 dependent mechanism. Lenalidomide treatment in combination with RhoU silencing determined a loss of cytoskeletal organization inhibiting cell migration, and a further increase in the percentage of cells in a resting phase. These results unravel a role for RhoU not only in regulating the migratory features of malignant plasma cells, but also in controlling cell cycle progression.

Idelalisib plus rituximab is effective in systemic AL amyloidosis secondary to chronic lymphocytic leukaemia.

Light chain amyloidosis is characterized by the progressive deposition of immunoglobulin light chains into the extracellular tissue, leading to organ dysfunction. Usually, it is associated with an underlying clonal plasma cell dyscrasia and rarely with chronic lymphocytic leukaemia. Herein, we described the first report of a patient with relapsed chronic lymphocytic leukaemia harbouring TP53 abnormalities who developed, histologically proven, systemic light chain amyloidosis who was treated with the PI3K inhibitor, idelalisib, and rituximab. Unfortunately, the patient had sudden death during sleep, likely caused by arrhythmia secondary to amyloid cardiomyopathy. Idelalisib was at least effective in reducing secretory free light chain, chronic lymphocytic leukaemia burden, and to improve the survival of patient.

Lenalidomide and dexamethasone in patients with POEMS syndrome: results of a prospective, open-label trial.

Given its anti-angiogenic activity, lenalidomide may have a role in the treatment of POEMS (Peripheral neuropathy, Organomegaly, Endocrinopathy, Monoclonal plasma cell disorder and Skin changes) syndrome. This prospective, open-label, pilot study evaluated the combination of lenalidomide + dexamethasone (RD) in 18 POEMS syndrome patients (13 pre-treated, 5 newly-diagnosed but ineligible for high-dose therapy). Treatment consisted of six cycles of lenalidomide (25 mg/day for 21 days followed by 7 days rest) plus dexamethasone (40 mg/once a week). Patients responding after six cycles continued treatment until progression or unbearable toxicity. The primary endpoint was the proportion of patients with either neurological or clinical improvement. The RD combination was considered as deserving further evaluation if 9 of the first 15 patients responded. Ten responses were observed among the first 15 enrolled patients, meeting the primary endpoint. Fifteen of 18 patients (83%) completed six RD cycles: 13 (72%) patients responded and nine had both clinical and neurological improvement. Among the 15 patients who completed the six RD cycles, four were still on treatment after a 25-month follow-up. At 39 months of follow-up, all patients were alive with a 3-year progression-free survival of 59%. No patient discontinued RD for toxicity. Overall, the RD regimen showed a high incidence of prolonged symptoms improvement and was well tolerated in most POEMS patients.

Application of confocal laser scanning microscopy for the diagnosis of amyloidosis.

We analysed specificity and sensitivity of confocal laser microscopy (CLSM) on tissue sections for a diagnosis of amyloidosis, in an attempt to reduce technical errors and better standardise pathological diagnosis. We first set up a protocol for the use of CLSM on this type of specimen, using a group of 20 amyloid negative and 20 positive samples. Of all specimens, 2, 4 and 8-µm sections were cut. Sections were stained with Congo red (CR) and thioflavin-T (ThT) and observed by cross-polarised light microscopy (CR-PL), epifluorescence microscopy (CRF-epiFM and ThT-epiFM) and CLSM (CRF-CLSM and ThT-CLSM). To validate the method in a diagnostic setting, we examined tissue samples from 116 consecutive patients with clinical suspicion of amyloidosis, selected from the period 2005 to 2014 from the database of the Pathology Unit of the University of Padua. The results were compared with those of transmission electron microscopy (TEM), which we consider as reference. We found that with CRF-CLSM, the false negative rate was reduced from 17 to 5%, while the sensitivity of detection increased to 12%. The results were in complete agreement with those of TEM ThT-CLSM; both sensitivity and specificity were 100%. Finally, ThT-CLSM results did not vary with section thickness, and small amounts of amyloid could even be detected in 2-µm sections. In conclusion, we found ThT-CLSM to be more sensitive as a screening method for amyloidosis than CR and ThT epifluorescence optical imaging. The method was easier to standardise, provided images with better resolution and resulted in more consistent pathologist diagnoses.

Free light chains and heavy/light chains in monitoring POEMS patients.

BACKGROUND: POEMS syndrome is defined by Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy and Skin changes. The vascular endothelial growth factor (VEGF) appears to play a key role in the pathogenesis of the syndrome, and its concentrations are deemed to correlate to disease activity. The aim of the present study was to verify whether other biochemical markers including serum free light chains (FLC) and heavy/light chains (HLC) would be of value in monitoring POEMS patients. METHODS: Fifty-three serum samples were collected from seven POEMS patients at diagnosis and during a follow-up period (range 14-56 months). VEGF was measured using an ELISA method, while FLC and HLC concentrations were measured using Binding Site reagents on a BNII (Siemens) nephelometer. RESULTS: At diagnosis all patients presented high VEGF concentrations, while the κ/λFLC ratio (FLCr) was within the reference range. Four patients had abnormal HLC, HLCκ/HLCλ (HLCr) and FLC values. The relationship between the trend of VEGF and both HLC and FLC during the follow-up was analysed by means of Cohen's κ coefficient. VEGF and HLC values displayed a significant κ-Cohen (0.537, p=0.002) in all chemotherapy-responder patients while in non-responders it did not. Conversely, in both responders and non-responders, VEGF and FLC values did not attain a significance on κ-Cohen analysis. In three out of four responders HLCr values increased, thus reflecting an improved clinical condition. CONCLUSIONS: The findings made in the present study indicate that HLC, either as intact immunoglobulin or as HLCr, may provide useful information, particularly in identifying responders and confirm that the role of FLC is unreliable in monitoring patients with POEMS syndrome.

Spontaneous splenic rupture following stem cell mobilization with G-CSF and plerixafor in AL amyloidosis.

BACKGROUND: AL amyloidosis is a rare plasma cell dyscrasia with multiorgan involvement. Good risk patients are candidate to high dose chemotherapy and autologous stem cell transplantation. However both transplantation and stem cell collection entail significant risk in such patients. Plerixafor is a novel mobilizing agent approved for use in "poor mobilizer" patients with lymphoma and multiple myeloma; experience in systemic amyloidosis patients is limited. CASE REPORT: We describe a case of spontaneous splenic rupture following administration of G-CSF and plerixafor in a patient with AL amyloidosis who previously underwent heart transplantation due to amyloid heart involvement. RESULTS AND CONCLUSION: This is the first report of spontaneous splenic rupture following stem cell mobilization with G-CSF and plerixafor in AL amyloidosis. The role of plerixafor has to be established. AL amyloidosis patients undergoing stem cell mobilization need careful monitoring of signs and symptoms of spontaneous splenic rupture.

Pentraxin-3 and VEGF in POEMS syndrome: a 2-year longitudinal study.

Circulating Pentraxin 3 (PTX3) and vascular endothelial growth factor (VEGF) levels were measured longitudinally (mean follow-up 2 years) by ELISA in 6 patients with polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome and 16 controls. Expression of PTX3 was also assessed (immunohistochemistry) on sural nerve biopsies from POEMS and vasculitic neuropathy patients. No correlation was found between PTX3 and VEGF levels in POEMS or controls. Sural nerve biopsies from vasculitic neuropathy patients, but not those from POEMS syndrome, showed strong PTX3 staining. PTX3, expression of vessel inflammation/remodeling, and VEGF, crucial pro-angiogenic cytokine, appear to be independently regulated in POEMS syndrome.

Inhibition of protein kinase CK2 with the clinical-grade small ATP-competitive compound CX-4945 or by RNA interference unveils its role in acute myeloid leukemia cell survival, p53-dependent apoptosis and daunorubicin-induced cytotoxicity.

BACKGROUND: The involvement of protein kinase CK2 in sustaining cancer cell survival could have implications also in the resistance to conventional and unconventional therapies. Moreover, CK2 role in blood tumors is rapidly emerging and this kinase has been recognized as a potential therapeutic target. Phase I clinical trials with the oral small ATP-competitive CK2 inhibitor CX-4945 are currently ongoing in solid tumors and multiple myeloma. METHODS: We have analyzed the expression of CK2 in acute myeloid leukemia and its function in cell growth and in the response to the chemotherapeutic agent daunorubicin We employed acute myeloid leukemia cell lines and primary blasts from patients grouped according to the European LeukemiaNet risk classification. Cell survival, apoptosis and sensitivity to daunorubicin were assessed by different means. p53-dependent CK2-inhibition-induced apoptosis was investigated in p53 wild-type and mutant cells. RESULTS: CK2a was found highly expressed in the majority of samples across the different acute myeloid leukemia prognostic subgroups as compared to normal CD34+ hematopoietic and bone marrow cells. Inhibition of CK2 with CX-4945, K27 or siRNAs caused a p53-dependent acute myeloid leukemia cell apoptosis. CK2 inhibition was associated with a synergistic increase of the cytotoxic effects of daunorubicin. Baseline and daunorubicin-induced STAT3 activation was hampered upon CK2 blockade. CONCLUSIONS: These results suggest that CK2 is over expressed across the different acute myeloid leukemia subsets and acts as an important regulator of acute myeloid leukemia cell survival. CK2 negative regulation of the protein levels of tumor suppressor p53 and activation of the STAT3 anti-apoptotic pathway might antagonize apoptosis and could be involved in acute myeloid leukemia cell resistance to daunorubicin.

Cobalamin deficiency: clinical picture and radiological findings.

Vitamin B12 deficiency causes a wide range of hematological, gastrointestinal, psychiatric and neurological disorders. Hematological presentation of cobalamin deficiency ranges from the incidental increase of mean corpuscular volume and neutrophil hypersegmentation to symptoms due to severe anemia, such as angor, dyspnea on exertion, fatigue or symptoms related to congestive heart failure, such as ankle edema, orthopnea and nocturia. Neuropsychiatric symptoms may precede hematologic signs and are represented by myelopathy, neuropathy, dementia and, less often, optic nerve atrophy. The spinal cord manifestation, subacute combined degeneration (SCD), is characterized by symmetric dysesthesia, disturbance of position sense and spastic paraparesis or tetraparesis. The most consistent MRI finding is a symmetrical abnormally increased T2 signal intensity confined to posterior or posterior and lateral columns in the cervical and thoracic spinal cord. Isolated peripheral neuropathy is less frequent, but likely overlooked. Vitamin B12 deficiency has been correlated negatively with cognitive functioning in healthy elderly subjects. Symptoms include slow mentation, memory impairment, attention deficits and dementia. Optic neuropathy occurs occasionally in adult patient. It is characterized by symmetric, painless and progressive visual loss. Parenteral replacement therapy should be started soon after the vitamin deficiency has been established.

Protein kinase CK2 inhibition down modulates the NF-κB and STAT3 survival pathways, enhances the cellular proteotoxic stress and synergistically boosts the cytotoxic effect of bortezomib on multiple myeloma and mantle cell lymphoma cells.

CK2 is a pivotal pro-survival protein kinase in multiple myeloma that may likely impinge on bortezomib-regulated cellular pathways. In the present study, we investigated CK2 expression in multiple myeloma and mantle cell lymphoma, two bortezomib-responsive B cell tumors, as well as its involvement in bortezomib-induced cytotoxicity and signaling cascades potentially mediating bortezomib resistance. In both tumors, CK2 expression correlated with that of its activated targets NF-κB and STAT3 transcription factors. Bortezomib-induced proliferation arrest and apoptosis were significantly amplified by the simultaneous inhibition of CK2 with two inhibitors (CX-4945 and K27) in multiple myeloma and mantle cell lymphoma cell lines, in a model of multiple myeloma bone marrow microenvironment and in cells isolated from patients. CK2 inhibition empowered bortezomib-triggered mitochondrial-dependent cell death. Phosphorylation of NF-κB p65 on Ser529 (a CK2 target site) and rise of the levels of the endoplasmic reticulum stress kinase/endoribonuclease Ire1α were markedly reduced upon CK2 inhibition, as were STAT3 phospho Ser727 levels. On the contrary, CK2 inhibition increased phospho Ser51 eIF2α levels and enhanced the bortezomib-dependent accumulation of poly-ubiquitylated proteins and of the proteotoxic stress-associated chaperone Hsp70. Our data suggest that CK2 over expression in multiple myeloma and mantle cell lymphoma cells might sustain survival signaling cascades and can antagonize bortezomib-induced apoptosis at different levels. CK2 inhibitors could be useful in bortezomib-based combination therapies.

Serum free light chain reference values: a critical approach.

OBJECTIVES: The clinical usefulness of serum free light chain (FLC) measurement in the management of patients with plasma cell proliferative disorders has been reported in several papers, and most clinical studies use the reference ranges declared by the manufacturer. The aim of the present study was to evaluate the reproducibility of FLCs immunoassay and to validate the reference range, before introducing it in routine setting. DESIGN AND METHODS: Internal quality control materials and a pool of fresh serum samples were used to evaluate imprecision; 162 fresh sera from healthy blood donors were analyzed to evaluate the reference range for FLCs. In order to verify the κ/λ FLC ratio, 43 sera from patients with polyclonal hypergammaglobulinemia were tested. The FLC immunoassay was performed using a nephelometer with the Freelite reagents. RESULTS: The imprecision studies performed using a serum pool tested with two different lots of reagents showed a mean CV of 16.09% for κFLC and of 16.72% for λFLC. Lower CV%s and different mean values were found by calculating the results from each specific lot separately, while different results were obtained using the control materials provided by the manufacturer. In reference subjects, the 2.5-97.5th percentiles were found to be 4.52-22.33 and 4.84-21.88mg/L for κFLC and λFLC, respectively. The range for κ/λ ratio (0.65-2.36) was validated with the values obtained from subjects with polyclonal hypergammaglobulinemia. In retesting 15 samples from blood donor subjects with a different lot of reagents, mean bias percentages of 17.60 for κFLC and 15.26 for λFLC were obtained. CONCLUSIONS: These findings confirm the lot-to-lot variability of the FLC assays also in the measurement of polyclonal light chains, as well as the need to carefully validate the reference values.