Normal and clonal B lineage cells can be distinguished by their differential expression of B cell antigens and adhesion molecules in peripheral blood from multiple myeloma (MM) patients--diagnostic and clinical implications

Does Waldenstrom's macroglobulinemia also cause bone destruction? A rare case report

Waldenstrom's macroglobulinemia (WM) is a rare type of malignant B-cell lymphoma. The main feature of WM is elevated serum monoclonal immunoglobulin M, similar to multiple myeloma (MM). Unlike in MM, the rarity of destructive bone lesions in WM has been repeatedly emphasized. We report a unique case of WM with a vertebral compression fracture as the first symptom. This case highlights that the presence or absence of bone destruction may not clearly distinguish between WM and MM. The possibility of WM should be considered in patients with vertebral fracture and destruction as the first presentation. Performing vertebral bone marrow aspiration biopsy during percutaneous vertebroplasty is a convenient and effective method to assist in the diagnosis of WM.

Detection of Circulating Tumor Plasma Cells in Monoclonal Gammopathies: Methods, Pathogenic Role, and Clinical Implications

Cancer dissemination and distant metastasis most frequently require the release of tumor cells into the blood circulation, both in solid tumors and most hematological malignancies, including plasma cell neoplasms. However, detection of blood circulating tumor cells in solid tumors and some hematological malignancies, such as the majority of mature/peripheral B-cell lymphomas and monoclonal gammopathies, has long been a challenge due to their very low frequency. In recent years, the availability of highly-sensitive and standardized methods for the detection of circulating tumor plasma cells (CTPC) in monoclonal gammopathies, e.g., next-generation flow cytometry (NGF), demonstrated the systematic presence of CTPC in blood in virtually every smoldering (SMM) and symptomatic multiple myeloma (MM) patient studied at diagnosis, and in the majority of patients with newly-diagnosed monoclonal gammopathies of undetermined significance (MGUS). These methods set the basis for further detailed characterization of CTPC vs. their bone marrow counterpart in monoclonal gammopathies, to investigate their role in the biology of the disease, and to confirm their strong impact on patient outcome when measured both at diagnosis and after initiating therapy. Here, we review the currently available techniques for the detection of CTPC, and determine their biological features, physiopathological role and clinical significance in patients diagnosed with distinct diagnostic categories of plasma cell neoplasms.

Sialyltransferase inhibition leads to inhibition of tumor cell interactions with E-selectin, VCAM1, and MADCAM1, and improves survival in a human multiple myeloma mouse model

Aberrant glycosylation resulting from altered expression of sialyltransferases, such as ST3 β-galactoside α2-3-sialyltransferase 6, plays an important role in disease progression in multiple myeloma (MM). Hypersialylation can lead to increased immune evasion, drug resistance, tumor invasiveness, and disseminated disease. In this study, we explore the in vitro and in vivo effects of global sialyltransferase inhibition on myeloma cells using the pan-sialyltransferase inhibitor 3F_ax-Neu5Ac delivered as a per-acetylated methyl ester pro-drug. Specifically, we show in vivo that 3F_ax-Neu5Ac improves survival by enhancing bortezomib sensitivity in an aggressive mouse model of MM. However, 3F_ax-Neu5Ac treatment of MM cells in vitro did not reverse bortezomib resistance conferred by bone marrow (BM) stromal cells. Instead, 3Fax-Neu5Ac significantly reduced interactions of myeloma cells with E-selectin, MADCAM1 and VCAM1, suggesting that reduced sialylation impairs extravasation and retention of myeloma cells in the BM. Finally, we showed that 3F_ax-Neu5Ac alters the post-translational modification of the α4 integrin, which may explain the reduced affinity of α4β1/α4β7 integrins for their counter-receptors. We propose that inhibiting sialylation may represent a valuable strategy to restrict myeloma cells from entering the protective BM microenvironment, a niche in which they are normally protected from chemotherapeutic agents such as bortezomib. Thus, our work demonstrates that targeting sialylation to increase the ratio of circulating to BM-resident MM cells represents a new avenue that could increase the efficacy of other anti-myeloma therapies and holds great promise for future clinical applications.

Risk factors associated with early mortality in patients with multiple myeloma who were treated upfront with a novel agents containing regimen

Background

Although the introduction of novel agents improved the survival outcomes in patients with multiple myeloma (MM), some patients died within one year (early mortality, EM) following diagnosis. In this study, we evaluated the EM rate, and investigated the risk factors associated with EM in MM patients.

Methods

Retrospective data from 542 patients who were initially treated with a novel agent-containing regimen were analyzed.

Results

The median overall survival (OS) for the entire cohort was 56.5 months. The median OS in the 2010–2014 group was longer than in the 2002–2009 group (59.2 months vs. 49.1 months, P = 0.054). The rate of EM was 13.8 %, and the most common causes of EM were infection and comorbidity. In multivariate analysis, the age-adjusted Charlson comorbidity index (ACCI ≥ 4), low body mass index (BMI < 20 kg/m²), thrombocytopenia, and renal failure were significantly associated with EM. The presence of none, 1, or ≥ 2 factors was associated with a 4.1 %, 14.3 %, or 27.4 % risk of EM (P < 0.001), respectively. The median OS times were significantly different depending on the presence of factors associated with EM (P < 0.001).

Conclusions

In conclusion, the ACCI (≥ 4), low BMI, thrombocytopenia and renal failure were strong predictors for EM in the novel agent era. The results of this study will help to identify patients at high risk for EM, and may be helpful to more accurately predict prognosis of MM patients in the novel-agent era.

Detection and Characterization of Circulating Tumour Cells in Multiple Myeloma

Multiple myeloma (MM) remains an incurable disease despite recent therapeutic improvements. The ability to detect and characterize MM circulating tumour cells (CTCs) in peripheral blood provides an alternative to replace or augment invasive bone marrow (BM) biopsies with a simple blood draw, providing real-time, clinically relevant information leading to improved disease management and therapy selection. Here we have developed and qualified an enrichment-free, cell-based immunofluorescence MM CTC assay that utilizes an automated digital pathology algorithm to distinguish MM CTCs from white blood cells (WBCs) on the basis of CD138 and CD45 expression levels, as well as a number of morphological parameters. These MM CTCs were further characterized for expression of phospho-ribosomal protein S6 (pS6) as a readout for PI3K/AKT pathway activation. Clinical feasibility of the assay was established by testing blood samples from a small cohort of patients, where we detected populations of both CD138pos and CD138neg MM CTCs. In this study, we developed an immunofluorescent cell-based assay to detect and characterize CTCs in MM.

The use of MAGE C1 and flow cytometry to determine the malignant cell type in multiple myeloma

The malignant cell phenotype of Multiple Myeloma (MM) remains unclear with studies proposing it to be either clonotypic B or proliferating plasma cells. Cancer/testis antigen MAGE C1 is being extensively studied in MM and it has been suggested that it is involved in the pathogenesis of the cancer. Therefore, we report on the use of MAGE C1 to determine the malignant cell phenotype in MM using flow cytometry. Bone marrow aspirate (BM) and peripheral blood (PB) was collected from twelve MM patients at diagnosis, as well as three MM disease-free controls. Mononuclear cells were isolated using density-gradient centrifugation, and stabilized in 80% ethanol, before analysis via flow cytometry using relevant antibodies against B cell development cell-surface markers and nuclear MAGE C1. MAGE C1 expression was observed consistently in the early stem cells (CD34+) and early pro-B to pre-B cells (CD34+/-/CD19+), as well as the proliferating plasma cells in both the MM PB and BM, while no expression was observed in the corresponding control samples. Monoclonality indicated a common origin of these cell types suggesting that the CD34+/MAGE C1+ are the primary malignant cell phenotype that sustains the downstream B cell maturation processes. Furthermore, this malignant cell phenotype was not restricted to the BM but also found in the circulating PB cells.

The rapid generation of recombinant functional monoclonal antibodies from individual, antigen-specific bone marrow-derived plasma cells isolated using a novel fluorescence-based method

Single B cell technologies, which avoid traditional hybridoma fusion and combinatorial display, provide a means to interrogate the naturally-selected antibody repertoire of immunized animals. Many methods enable the sampling of memory B cell subsets, but few allow for the direct interrogation of the plasma cell repertoire, i.e., the subset of B cells responsible for producing immunoglobulin in serum. Here, we describe the use of a robust and simple fluorescence-based technique, called the fluorescent foci method, for the identification and isolation of antigen-specific IgG-secreting cells, such as plasma cells, from heterogeneous bone marrow preparations. Following micromanipulation of single cells, cognate pairs of heavy and light chain variable region genes were recovered by reverse transcription (RT)-polymerase chain reaction (PCR). During the PCR, variable regions were combined with a promoter fragment and a relevant constant region fragment to produce two separate transcriptionally-active PCR (TAP) fragments that were directly co-transfected into a HEK-293F cell line for recombinant antibody expression. The technique was successfully applied to the generation of a diverse panel of high-affinity, functional recombinant antibodies to human tumor necrosis factor (TNF) receptor 2 and TNF derived from the bone marrow of immunized rabbits and rats, respectively. Progression from a bone marrow sample to a panel of functional recombinant antibodies was possible within a 2-week timeframe.

Effect of levofloxacin prophylaxis for prevention of severe infections in multiple myeloma patients receiving bortezomib-containing regimens

Fluoroquinolone is recommended as a prophylactic antibiotic for high-risk patients with profound neutropenia. We previously reported that multiple myeloma (MM) patients who received bortezomib-based regimens were at higher risk of severe infections (30.9%) associated with lymphocytopenia. In the study, we evaluated whether severe infectious complications can be prevented by prophylactic administration of oral levofloxacin in MM patients treated with bortezomib-based regimens. A total of 80 patients received oral levofloxacin 500 mg daily during the median four cycles of treatment. The prophylactic group (n = 80) with levofloxacin showed significantly decreased severe infections compared to a historical control group (n = 139) without levofloxacin prophylaxis during treatment of bortezomib-based regimens (17.5 vs. 30.9%, P = 0.037). In the prophylactic group, two patients (2.5%) died of pneumonia and septic shock. Four patients (5%) stopped levofloxacin due to side effects that consisted of gastrointestinal discomfort (2.5%), itching sense (1.25%), and QTc prolongation (1.25%). In conclusion, prophylaxis with levofloxacin may be effective in the prevention of severe infection in MM patients receiving bortezomib-based regimens. A prospective randomized study is needed to test the prophylactic effect of levofloxacin in MM patients treated with bortezomib-based regimens.

Detection of monoclonal IGH rearrangements in circulating cells from healthy first-degree relatives of patients with multiple myeloma

Multiple myeloma (MM) is characterized by abnormal proliferation of clonal plasma cells or monoclonal plasmacytosis, resulting in accumulation of clonal immunoglobulins. Monoclonal gammopathy of unknown significance (MGUS) is considered a premorbid stage for developing MM. Studies have shown an increased risk of MGUS in first-degree relatives of patients with MM. Detection of immunoglobulin heavy chain gene (IGH) rearrangement provides a useful tool for assessing clonality. The aim of this study was to determine clonality in peripheral blood samples from 61 healthy first-degree relatives of MM probands by sorting circulating lymphocytes and detection of the IGH rearrangements in these cells. We detected 16 out of 61 (26.2%) relatives with monoclonal complete and incomplete IGH rearrangements; only three of them showed elevated monoclonal immunoglobulin in the serum protein electrophoresis. We conclude that this strategy is able to identify efficiently clonality in peripheral blood samples from first-degree relatives of patients with MM, who have a non-negligible risk of developing MGUS or other plasma cell dyscrasias.

Circulating clonotypic B cells in multiple myeloma and monoclonal gammopathy of undetermined significance

The B-cell compartment in which multiple myeloma stem cells reside remains unclear. We investigated the potential presence of mature, surface-membrane immunoglobulin-positive B lymphocytes clonally related to the tumor bone marrow plasma cells among different subsets of peripheral blood B cells from ten patients (7 with multiple myeloma and 3 with monoclonal gammopathies of undetermined significance). The presence of clonotypic immunoglobulin heavy chain gene rearrangements was determined in multiple highly-purified fractions of peripheral blood B-lymphocytes including surface-membrane IgM(+) CD27(-) naïve B-lymphocytes, plus surface-membrane IgG(+), IgA(+) and IgM(+) memory CD27(+) B cells, and normal circulating plasma cells, in addition to (mono)clonal plasma cells, by a highly-specific and sensitive allele-specific oligonucleotide polymerase chain reaction directed to the CDR3 sequence of the rearranged IGH gene of tumor plasma cells from individual patients. Our results showed systematic absence of clonotypic rearrangements in all the different B-cell subsets analyzed, including M-component isotype-matched memory B-lymphocytes, at frequencies <0.03 cells/μL (range: 0.0003-0.08 cells/μL); the only exception were the myeloma plasma cells detected and purified from the peripheral blood of four of the seven myeloma patients. These results indicate that circulating B cells from patients with multiple myeloma and monoclonal gammopathies of undetermined significance are usually devoid of clonotypic B cells while the presence of immunophenotypically aberrant myeloma plasma cells in peripheral blood of myeloma patients is a relatively frequent finding.

Immune dysfunction in multiple myeloma

SUMMARY Although there have been advances in the field, multiple myeloma, the second most common hematological malignancy, remains an incurable disease characterized by ever-shortening cycles of treatment and relapse. Myriad experimental and observational studies over the last few decades have comprehensively documented a state of profound immune dysfunction, which is progressive and correlated with disease stage. Nonetheless, immune responses against the tumor have demonstrated efficacy ex vivo, in animal models and in human disease. In this review we examine the immune defects in multiple myeloma and consider current and future approaches toward correction and manipulation of immune responses to affect clinically useful antitumor effects.

Competition between clonal plasma cells and normal cells for potentially overlapping bone marrow niches is associated with a progressively altered cellular distribution in MGUS vs myeloma

Disappearance of normal bone marrow (BM) plasma cells (PC) predicts malignant transformation of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) into symptomatic multiple myeloma (MM). The homing, behavior and survival of normal PC, but also CD34(+) hematopoietic stem cells (HSC), B-cell precursors, and clonal PC largely depends on their interaction with stromal cell-derived factor-1 (SDF-1) expressing, potentially overlapping BM stromal cell niches. Here, we investigate the distribution, phenotypic characteristics and competitive migration capacity of these cell populations in patients with MGUS, SMM and MM vs healthy adults (HA) aged >60 years. Our results show that BM and peripheral blood (PB) clonal PC progressively increase from MGUS to MM, the latter showing a slightly more immature immunophenotype. Of note, such increased number of clonal PC is associated with progressive depletion of normal PC, B-cell precursors and CD34(+) HSC in the BM, also with a parallel increase in PB. In an ex vivo model, normal PC, B-cell precursors and CD34(+) HSC from MGUS and SMM, but not MM patients, were able to abrogate the migration of clonal PC into serial concentrations of SDF-1. Overall, our results show that progressive competition and replacement of normal BM cells by clonal PC is associated with more advanced disease in patients with MGUS, SMM and MM.

Targeting and internalization of sterically stabilized liposome modified with ZCH-4-2E8

Sterically stabilized liposome (SL) modified with 2E8 monoclonal antibody (2E8-SL) was prepared in order to evaluate its targeting ability and internalization efficiency against tumor cells with high expression of CD19. 2E8 was coupled to the surface of SL using post-insertion technique. The shape of liposomes was observed under a transmission electronic microscope. The average size of liposomes was determined by using the Zetasizer instrument. The binding and internalization of 2E8-SL against tumor cells with higher expression of CD19 were tested by flow cytometry and confocal microscopy. The mean diameter of 2E8-SL was 121.25 nm. 2E8-SL was stable after up to 24 days in various buffers. 2E8-SL showed specific binding to tumor cells with high expression of CD19, including B cells in peripheral blood mononuclear cells (PBMCs). 2E8-SL could efficiently internalize into Nalm6 cells with CD19 high expression. It is suggested that 2E8-SL may serve as useful delivery carrier of anti-cancer drugs targeting to hematological malignant tumors with CD19 high expression.

Plasma cell purification from murine bone marrow using a two-step isolation approach

Interest in plasma cells has increased greatly in the past decade. While several studies have examined the longevity and transcriptional control of antibody secreting cells in vivo, few studies have examined freshly isolated plasma cells ex vivo. Studies of primary plasma cells have been limited primarily due to the difficulty of isolating the large numbers of plasma cells necessary for experiments. In this protocol, plasma cells are purified from murine bone marrow in approximately 5 hours, following a two-step isolation method utilizing column enrichment and FACS-sorting based on CD138 (Syndecan-1) surface expression.

Expression and purification of two anti-CD19 single chain Fv fragments for targeting of liposomes to CD19-expressing cells

Antibody-targeted liposomal anticancer drugs combine the specificity of antibodies with large payloads of entrapped drugs. We previously showed that liposomal doxorubicin (DXR) targeted via anti-CD19 monoclonal antibodies (mAb) or their Fab' fragments against the B-cell antigen CD19 led to improved therapeutic effects in murine B-cell lymphoma models relative to non-targeted liposomal DXR. We now are examining the use of anti-CD19 single chain fragments of the antibody variable region (scFv) as a targeting moiety, to test the hypothesis that scFv have advantages over full-sized mAb or Fab' fragments. We expressed two different anti-CD19 scFv constructs, HD37-C and HD37-CCH in E. coli, and purified the scFvs using two different methods. The HD37-CCH construct was selected for coupling studies due to its relative stability and activity in comparison to HD37-C. When coupled to liposomes, the HD37-CCH scFv showed increased binding in vitro to CD19-positive Raji cells, compared to non-targeted liposomes. Cytotoxicity data showed that HD37-CCH scFv-targeted liposomes loaded with DXR were more cytotoxic than non-targeted liposomal DXR. Our results suggest that anti-CD19 scFv constructs should be explored further for their potential in treating B-lymphoid leukemias and lymphomas.

Early mortality after diagnosis of multiple myeloma: analysis of patients entered onto the United kingdom Medical Research Council trials between 1980 and 2002--Medical Research Council Adult Leukaemia Working Party

PURPOSE

Early mortality in multiple myeloma (MM) is usually attributed to combined effects of active disease and comorbid factors. We have studied early deaths in a series of large multicenter trials to assess direct causes of death, their predictability, and whether current management strategies have reduced their frequency.

PATIENTS AND METHODS

A total of 3,107 newly diagnosed patients entered onto United Kingdom Medical Research Council MM trials from 1980 to 2002 were studied. Trial files, final clinical summaries, and postmortem reports were analyzed.

RESULTS

Death within 60 days of trial entry occurred in 299 patients (10%). Logistic regression modeling identified beta 2-microglobulin, performance status, and age as the most important predictors of early death, but only with 61% sensitivity and 73% specificity. Forty-five percent of deaths were attributable to infection, which was often associated with bone pain (particularly thoracic pain) and delay in presenting to medical care. Neutropenia was present at diagnosis in only 11 of the 135 deaths from infection. Renal failure was present in 28% of early deaths and was linked to light-chain MM, hypercalcemia, dehydration, and nonsteroidal anti-inflammatory drugs. There was no time related reduction in the percentage or nature of early deaths in 1,550 patients older than 65 years receiving similar therapy between 1982 and 2002.

CONCLUSION

A tenth of patients die within 60 days of diagnosis of MM. Infection and renal failure are the main direct causes of early mortality, which cannot be accurately predicted by presenting prognostic features. All patients should be considered at high risk of death during induction therapy.

Short-lived plasma blasts are the main B cell effector subset during the course of multiple sclerosis

Multiple sclerosis is a chronic inflammatory and demyelinating disorder of the CNS with an unknown aetiology. Although intrathecal immunoglobulin G (IgG) synthesis is a key feature of the disease, little is still known about the B cell response in the CNS of multiple sclerosis patients. We analysed the phenotype and kinetics of different B cell subsets in patients with multiple sclerosis, infectious disease (IND) and non-inflammatory neurological disease (NIND). B cells were detected in the CSF of multiple sclerosis and IND patients, but were largely absent in NIND patients. In the CSF, the majority of B cells had a phenotype of memory B cells and short-lived plasma blasts (PB); plasma cells were absent from the compartment. The proportion of PB was highest in multiple sclerosis patients and patients with acute CNS infection. While PB disappeared rapidly from the CSF after resolution of infection in IND patients, these cells were present at high numbers throughout the disease course in multiple sclerosis patients. CSF PB numbers in multiple sclerosis patients strongly correlated with intrathecal IgG synthesis and inflammatory parenchymal disease activity as disclosed by MRI. This study identifies short-lived plasma blasts as the main effector B cell population involved in ongoing active inflammation in multiple sclerosis patients.

Recapitulation of B cell differentiation in the central nervous system of patients with multiple sclerosis

Clonally expanded populations of B cells carrying somatic mutations of Ig variable (V) region genes have been detected in the CNS of subjects with multiple sclerosis (MS), suggesting that a process of B cell affinity maturation with ensuing production of potentially pathogenic autoantibodies may occur inside the CNS. Here, we have characterized the B cell subsets present in the cerebrospinal fluid (CSF) of MS patients and of individuals with other inflammatory neurological disorders by flow cytometry. CD19(+)CD38(high+)CD77(+), Ki67(+), Bcl-2(-) centroblasts, i.e., a B cell subset found exclusively in secondary lymphoid organs, were detected in the CSF but not in paired peripheral blood from both patient groups. CD27(+)IgD(-) memory B cells, i.e., cells with hyper-mutated IgV genes, were significantly increased in the CSF vs. paired peripheral blood and displayed up-regulation of the CD80 and CD86 costimulatory molecules and of CC chemokine receptor (CCR) 1, CCR2, and CCR4 in both patient groups. Lymphotoxin-alpha, CXC ligand (CXCL) 12, and CXCL13, key mediators of lymphoid neogenesis, were present in the CSF from patients with MS and other inflammatory neurological disorders and were expressed in MS brain tissue, with selective localization in the outer layer of the capillary vessel wall. In conclusion, this study suggests that a compartmentalized B cell response occurs within the CNS during an ongoing inflammatory reaction, through a recapitulation of all stages of B cell differentiation observed in secondary lymphoid organs. The presence of lymphotoxin-alpha, CXCL12, and CXCL13 in the CNS may provide favorable microenvironmental conditions for these events.

CD106 and activated-CD29 are expressed on myelomatous bone marrow plasma cells and their downregulation is associated with tumour progression

Malignant plasma cells (PC) from multiple myeloma (MM) patients characteristically home to the bone marrow (BM). High numbers of tumour cells are found in the peripheral blood (PB) only at end-stage disease (secondary plasma cell leukaemia, PCL) in a minority of patients. Using flow cytometric and fluorescence in situ hybridization (FISH) analysis, a high percentage of tumoral BM PC from untreated patients was found to express CD106. In addition, these cells also expressed an activated form of CD29, as determined using the CD29 activation reporter monoclonal antibody HUTS-21. Adhesion-binding experiments showed that CD106+-activated CD29+ BM PC from these patients adhered to fibronectin (FN) in a CD29/CD49d-dependent manner. In contrast, marrow PC from progressive patients and BM or circulating malignant cells from secondary PCL patients expressed lower levels or were negative for CD106 and activated CD29, respectively, with a decreased or zero ability to adhere to FN. The expression of constitutive CD29 and CD49d, however, was similar during disease progression. We conclude that BM myelomatous cells co-express CD106 and a functionally active form of CD29. Moreover, our results suggest that the loss of expression and/or function of these antigens are associated with the progression of MM and may explain the exit of tumoral cells from the BM.

Disturbed peripheral B lymphocyte homeostasis in systemic lupus erythematosus

In patients with active systemic lupus erythematosus (SLE), a marked B lymphocytopenia was identified that affected CD19(+)/CD27(-) naive B cells more than CD19(+)/CD27(+) memory B cells, leading to a relative predominance of CD27-expressing peripheral B cells. CD27(high)/CD38(+)/CD19(dim)/surface Ig(low)/CD20(-)/CD138(+) plasma cells were found at high frequencies in active but not inactive SLE patients. Upon immunosuppressive therapy, CD27(high) plasma cells and naive CD27(-) B cells were markedly decreased in the peripheral blood. Mutational analysis of V gene rearrangements of individual B cells confirmed that CD27(+) B cells coexpressing IgD were memory B cells preferentially using V(H)3 family members with multiple somatic mutations. CD27(high) plasma cells showed a similar degree of somatic hypermutation, but preferentially employed V(H)4 family members. These results indicate that there are profound abnormalities in the various B cell compartments in SLE that respond differently to immunosuppressive therapy.

Immunogenicity of vaccination against influenza, Streptococcus pneumoniae and Haemophilus influenzae type B in patients with multiple myeloma

Vaccination against influenza and Streptococcus pneumoniae is recommended for elderly and immunocompromised individuals. However, there is little information concerning the efficacy of vaccination in specific groups of patients. In this study, 52 patients underwent vaccination against influenza, S. pneumoniae and Haemophilus influenzae type b (Hib) as they attended hospital outpatient clinics. Serum was analysed prior to vaccination and 4-6 weeks afterwards. Antibody titres against S. pneumoniae and Hib were compared with reference values corresponding to the geometric mean titres of a healthy UK population. For influenza vaccination, haemagglutination inhibition (HI) titres were measured against three inactivated strains; a titre of > or = 1/40 was considered protective. No patient had protective titres to all three antigens prior to vaccination and 41 patients (85%) had titres < 1/40 to all 3 strains. Post vaccination only 9/48 patients (19%) achieved protective antibody titres. Resistance to S. pneumoniae and response to Pneumovax II was also poor: prevaccination, 45 patients (93%) had suboptimal antibody titres and in 26/43 patients (61%) titres remained low post vaccination. Resistance to Hib and response to vaccination was comparable with the healthy adult UK population. These results question the practice of routine influenza and pneumococcal vaccination in myeloma patients.

The role of adhesion receptors in the pathogenesis of multiple myeloma

There is now an improved understanding of the types of adhesion receptors present on normal and malignant plasma cells. This knowledge has been helpful in identifying plasma cells and in beginning to understand the pathogenesis of myeloma. Future research is needed to delineate the signaling pathways used by the plasma cell after the adhesion receptor binds to its ligands. This information should help in designing more effective therapy for this fatal disease.