Characterization of a myeloma patient with a life-threatening hemorrhagic diathesis: presence of a lambda dimer protein inhibiting shear-induced platelet aggregation by binding to the A1 domain of von Willebrand factor

Bleeding and Thrombosis in Multiple Myeloma: Platelets as Key Players during Cell Interactions and Potential Use as Drug Delivery Systems

Multiple myeloma (MM) is a hematological malignancy originated in the bone marrow and characterized by unhindered plasma cell proliferation that results in several clinical manifestations. Although the main role of blood platelets lies in hemostasis and thrombosis, platelets also play a pivotal role in a number of other pathological conditions. Platelets are the less-explored components from the tumor microenvironment in MM. Although some studies have recently revealed that MM cells have the ability to activate platelets even in the premalignant stage, this phenomenon has not been widely investigated in MM. Moreover, thrombocytopenia, along with bleeding, is commonly observed in those patients. In this review, we discuss the hemostatic disturbances observed in MM patients and the dynamic interaction between platelets and myeloma cells, along with present and future potential avenues for the use of platelets for diagnostic and therapeutic purposes.

Acquired von Willebrand syndrome and lymphoid neoplasms: A review of malignancy management, and propositions of practical recommendations

INTRODUCTION

Acquired von Willebrand syndrome (AWS) is a rare and potentially life-threatening bleeding disorder. AWS is primarily associated with lymphocyte-related disorders (AWS-LRD), such as lymphoma and IgM monoclonal gammopathy of undetermined significance (MGUS), and plasmocyte-related disorders (AWS-PRD), such as non-IgM MGUS and myeloma. Symptomatic treatments are important to control and prevent bleeding, but AWS-LRD and AWS-PRD can only be cured by targeting the responsible clonal cell. No reviews exist on this specific subgroup of AWS.

AIM

We performed a literature review to help manage these rare cases.

METHOD

Thirty-two AWS-PRD and 43 AWS-LRD cases with data on malignancy treatment were reported in 56 articles from the Medline database.

RESULTS

LRDs were exclusively indolent and primarily associated with IgM monoclonal compounds. LRDs and PRDs may be treated because of severe bleeding symptoms, but severe VWF deficiency did not necessarily correlate with severe bleeding. Immunosuppressive drugs in AWS-PRD, including rituximab, provided an overall response rate of AWS (AWS-ORR) of 30% (3/10), including short responses. Anti-myeloma drugs provided an AWS-ORR of 71.4% (20/28), with long-lasting remissions. Bortezomib was the most commonly used drug and provided an AWS-ORR of 66.7% (6/9), including therapeutic associations with other anti-myeloma drugs. Autologous and allogeneic stem cell transplantation was performed in eight and two patients, respectively, and some details on the management of AWS during these procedures were provided. Rituximab in AWS-LRD provided an AWS-ORR of 60% (3/5), and a chemotherapy + rituximab regimen increased the AWS-ORR to above 50%. Bleeding syndrome in AWS-PRD and AWS-LRD generally improved prior to AWS biological improvement.

CONCLUSION

Long term remission of AWS due to lymphoid neoplasms is attainable by treating the underlying clonal cell. Some data and recommendations are provided to help answer difficult questions, including treatment timing, choice of drug, and the timing of evaluations and treatment changes.

Platelet hyperactivation in multiple myeloma is also evident in patients with premalignant monoclonal gammopathy of undetermined significance

Thrombotic events are common in patients with multiple myeloma (MM), smouldering myeloma (SM) and monoclonal gammopathy of undetermined significance (MGUS). Previous studies have indicated platelet hyperactivation as a feature of thrombotic risk in MM, but there is a dearth of data in MGUS. In the present study, multiparameter analysis of platelet activation and responsiveness was investigated by flow cytometry in patients with MGUS, SM/MM and healthy controls (HCs). The median platelet surface CD63 levels, annexin V and PAC-1 antibody (specific for activated integrin αIIbβ3) binding were significantly elevated in patients with MGUS versus the HCs. These markers were also elevated in SM/MM, but not significantly. In all, 74% of MGUS and 38% of SM/MM patients had one or more elevated marker of platelet activation, compared to 19% of the HCs. Marker-specific hyporesponsiveness of platelets to agonist [adenosine diphosphate (ADP), thrombin receptor-activating peptide 6] stimulation in vitro was observed, with significantly reduced surface levels of P-selectin in response to ADP in patients with MGUS. Platelet-leucocyte aggregates were not altered in patients, while platelet-associated immunoglobulins were elevated in a subset of patients. Overall, we found that platelet hyperactivation is prevalent in both MGUS and SM/MM patients and is potentially related to hyporesponsiveness. These observations suggest that further investigation of the predictive and prognostic value of platelet hyperactivation in such patients is warranted.

Disease progression and defects in primary hemostasis as major cause of bleeding in multiple myeloma

BACKGROUND AND OBJECTIVES

In patients with multiple myeloma (MM), unexpected bleeding complications remain a major issue. Since routine coagulation parameters are often inconspicuous, diagnosis and treatment of the underlying coagulation disorders are challenging.

PATIENTS AND METHODS

In our single-center observational study, we analyzed 164 patients with MM for coagulation disorders and bleeding complications.

RESULTS

Prolonged closure times (CTs), measured by PFA-100, were the most common, abnormal coagulation test, found in 66% of bleeding patients vs 5% in non-bleeding, followed by qualitative defects of von Willebrand factor (VWF:CB/VWF:Ag ratios), found in 34% vs 1% in the non-bleeding group. Increased serum free light chains (SFLC) and SFLC ratios were significantly associated with prolonged CTs and acquired von Willebrand syndrome (AVWS). Prolonged CTs and AVWS were associated with disease progression, determined by dynamics of SFLC ratios (P < .001), serum creatinine level (P = .013), Beta-2 microglobulin (P = .03), LDH (P = .016), and bone marrow infiltration (P < .001). Of note, response to myeloma therapy was frequently correlated with normalization of coagulation parameters.

CONCLUSIONS

Bleeding complications in MM are predominantly caused by defects in primary hemostasis and associated with disease progression. In a peri-interventional workup, determination of CTs and VWF:CB/VWF:Ag ratios are of significant importance to assess bleeding risk.

Multiple Myeloma as the Underlying Cause of Thrombotic Microangiopathy Leading to Acute Kidney Injury: Revisiting a Very Rare Entity

Thrombotic microangiopathy (TMA) describes a pathological process of microvascular thrombosis, consumptive thrombocytopenia, and microangiopathic hemolytic anemia, leading to end-organ ischemia and infarction, affecting particularly the kidney and brain. TMA is a pathological feature of a number of clinical disorders including thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, and atypical hemolytic uremic syndrome. Rare but important, TMA may also occur in malignancy, connective tissue disease, malignant hypertension, and renal transplantation (rejection or drug toxicity). We present a very rare case where the patient developed acute kidney injury from TMA but found to have multiple myeloma as the possible underlying etiology.

Effect of serum monoclonal protein concentration on haemostasis in patients with multiple myeloma

Abnormalities in haemostasis are often detected in patients with multiple myeloma and the fundamental factors that lead to these abnormities are worthy of exploration. The objective of this study was to investigate bleeding diathesis and coagulopathy in different multiple myeloma types or stages and assess how paraprotein concentration contributes to differences in these conditions. Haemostasis screening tests and serum monoclonal protein (M protein) concentration were retrospectively analysed in 101 patients newly diagnosed with multiple myeloma from January 2012 to April 2014. No significant differences were found between bleeding diathesis and types or International Staging System (ISS) stages of multiple myeloma; however, prolonged thrombin time (TT) was found in most of patients (77.7%) and was positively related to light-chain concentration (P ≤ 0.01). Prolonged prothrombin time (PT) was more obvious in IgA and IgG-type multiple myeloma than in the light-chain type (P ≤ 0.01). With increased clinical staging, PT remarkably increased (P ≤ 0.01). M protein concentration was significantly higher in patients with prolonged PT than in those with normal PT (P ≤ 0.01). The D-dimer mean was significantly higher than normal (>0.5 μg/ml) (P ≤ 0.01). Fibrinogen was negatively related to M protein levels (P ≤ 0.01); however, there was no correlation between activated partial thromboplastin time (APTT) and multiple myeloma stages or types, M protein levels and serum light-chain concentration (P ≥ 0.05). Patients with light-chain type multiple myeloma were more likely to have prolonged TT than patients with other types. M protein levels had an obvious effect on PT. Prolonged PT was more common in IgA and IgG-type multiple myeloma. Abnormal haemostasis test results are not always accompanied by clinically apparent haemostatic complications.

Distinct mechanisms account for acquired von Willebrand syndrome in plasma cell dyscrasias

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that may cause life-threatening hemorrhages in patients with plasma cell dyscrasias (PCDs). Early diagnosis and treatment require a thorough understanding of its underlying pathophysiology. Two patients with IgG MGUS presented with dramatically decreased plasma von Willebrand factor (VWF) and a severe type-1 pattern on multimer analysis. A prompt response to intravenous immunoglobulins (IVIG), but not to VWF/FVIII, was consistent with accelerated immunologic clearance of plasma VWF. Another IgG MGUS patient showed a type-2 pattern and a less pronounced response to IVIG, suggesting that additional mechanism(s) contributed to AVWS evolution. In a patient with Waldenström's macroglobulinemia and severe depletion of plasma VWF, multimer analysis indicated association of the IgM paraprotein with VWF before, but not after plasmapheresis, resulting in destruction of the agarose gel and a characteristically distorted band structure of VWF multimers. A type-2 pattern with highly abnormal VWF triplets and laboratory evidence of excessive fibrinolytic activity suggested that plasmin-mediated VWF degradation contributed to AVWS in a patient with multiple myeloma (MM) and AL amyloidosis. Finally, in a patient with IgG MM, maximally prolonged PFA-100® closure times and a specific defect in ristocetin-induced platelet agglutination, both of which resolved after remission induction, indicated interference of the paraprotein with VWF binding to platelet GPIb. Importantly, in none of the six patients, circulating autoantibodies to VWF were detected by a specific in-house ELISA. In summary, when evaluating PCD patients with severe bleeding symptoms, AVWS due to various pathogenic mechanisms should be considered.

The effect of paraprotein on platelet aggregation

BACKGROUND

Some patients with paraproteinemia have platelet aggregation disorders and the aim of this study was to examine disturbance of platelet aggregation in healthy blood donors by isolated paraprotein in vitro.

METHODS

Using Rivanol, paraprotein was separated from the serum of ten patients with paraproteinemia, who had decreased platelet aggregation with several inducers. Platelet aggregation in ten healthy donors was measured with and without addition of the isolated induced paraprotein. The test was repeated with added human immunoglobulins for intravenous use.

RESULTS

Average of maximal levels of platelet aggregation has been significantly decreased in plasma rich in platelets (PRP) of healthy donors after addition of paraprotein when inducers are used: adenosine diphosphate (ADP) (P = 0.007), collagen (COL) (P = 0.008), ristocetin (RIS) (P = 0.001), and epinephrine (EPI) (P = 0.002). Average of latent time of platelet aggregation was significantly prolonged in healthy donors after addition of paraprotein with inducers: COL (P = 0.008), RIS (P = 0.008) and EPI (P = 0.006) while addition of human immunoglobulins caused no change in platelet aggregation. In comparison, when human immunoglobulins were added, maximal platelet aggregation and latent time did not change significantly. Paraprotein isolated from patients with paraproteinamia, who had decrease platelet aggregation, had significantly decreased platelet aggregation when added to PRP of healthy donors, in vitro.

CONCLUSION

Platelet aggregation was not significantly changed was confirmed with addition of human immunoglobulins.

Specific binding of paraprotein to platelet receptors as a cause of platelet dysfunction in monoclonal gammopathies

The study included 48 untreated patients with monoclonal gammopathies (MG). Paraprotein was isolated from the serum of 10 patients with decreased platelet aggregation. Platelet aggregation was measured before and after the addition of the isolated paraprotein to platelet-rich plasma (PRP) from 10 healthy donors, in vitro. Expression of platelet von Willebrand factor (vWF) receptor glycoprotein (GP)Ib and platelet collagen receptor GPVI was determined by flow cytometry in the PRP of healthy donors before and after the addition of isolated paraprotein using the monoclonal antibodies, CD42b (for GPIb) and CD36 (for GPVI). Flowcytometry showed that expression of CD42b and CD36 positive cells was reduced after the addition of isolated paraprotein to PRP from healthy donors (p < 0.001). These investigations demonstrated that paraprotein causes platelet dysfunction in patients with MG due to specific binding to the platelet vWF receptor GPIb and platelet collagen receptor GPVI.

Acquired von Willebrand syndrome in multiple myeloma

Acquired von Willebrand syndrome (AvWS) is an uncommon complication of multiple myeloma (MM), and it is believed to be connected with paraprotein. The aim of this study was to determine the incidence of AvWS in patients with MM, and estimate the role of paraprotein in its occurrence. The study included 40 patients with MM. The plasma level of paraprotein, platelet adhesion on glass pearls, plasma von Willebrand factor antigen concentration, and ristocetin-induced platelet aggregation (RIPA) were measured initially. Absence of RIPA was found in six patients with MM (15%); however, all six of them had normal levels of von Willebrand factor antigen. Paraprotein was isolated from the serum of these patients. Platelet aggregation was measured in six healthy donors before and after addition of the isolated paraprotein. RIPA was significantly decreased in healthy donors in the presence of paraprotein (P<0·001). The same test was repeated with added human immunoglobulins for intravenous use without any change in RIPA. A significant negative correlation between plasma paraprotein level and RIPA was found (P<0·001). These investigations have shown that paraprotein is associated with AvWS in patients with MM.

Pathogenesis and management of bleeding and thrombosis in plasma cell dyscrasias

Unexpectedly high rates of venous thromboembolic events (VTE) concurrent with the introduction of highly effective immune modulating drugs thalidomide and lenolidomide for treatment of multiple myeloma have focused attention on the incidence and underlying pathophysiology of VTE in patients with plasma cell dyscrasias, and on thromboprophylaxis approaches. While bleeding complications are relatively uncommon in patients with lymphoproliferative disorders, acquired von Willebrand syndrome, typically occurring in patients with monoclonal gammopathy of unknown significance, and acquired coagulopathies associated with primary amyloidosis can present with haemorrhagic complications and both are challenging to manage. This review highlights these important haemostasis-related complications of plasma cell dyscrasias and provides an overview of other uncommon bleeding and thrombotic events that can affect diagnostic and therapeutic management of clonal plasma cell disorders. Due to the infrequency of most of these haemostasis complications, available information is typically based on retrospective cases or series.

Bleeding and Thrombosis Risks in Plasma Cell Dyscrasias

Major, spontaneous bleeding is uncommon in patients with plasma cell dyscrasias despite frequent abnormal screening hemostasis tests. However, acquired von Willebrand deficiency and light-chain (AL) amyloidosis, and amyloidosis complicating multiple myeloma can present with serious hemorrhagic complications that are challenging to manage. While patients with monoclonal gammapathy of undetermined significance and multiple myeloma share an intrinsic increased risk of venous thromboembolic events (VTE), treatment with thalidomide and lenalidomide increases the incidence of VTE in certain multiple myeloma patient subsets. Our understanding of the complex interactions among malignant plasma cells, inflammatory and hemostasis pathways, and treatment modalities that combine to produce thrombotic complications is incomplete. Prospective, randomized trials are clearly needed to assist clinicians in providing optimal VTE prophylaxis to their patients with plasma cell dyscrasias.