Long-term persistence in patients with osteoporosis receiving denosumab in routine practice: 36-month non-interventional, observational study.

Persistence rates over 36 months with denosumab in patients diagnosed with osteoporosis in a real-world setting were examined, along with baseline patient characteristics predictive of persistence. This study represents the longest observational period with denosumab persistence and shows higher persistence rates when compared to bisphosphonates. INTRODUCTION: The study objective was to describe long-term persistence with denosumab among patients treated for osteoporosis in a real-world setting. We also sought to examine patient characteristics predictive of persistence. Lastly, this study attempted to place the results in context by conducting a literature review of published persistence data for denosumab. METHODS: This retrospective, non-interventional study analyzed 1158 patients from a specialty community private practice to assess patient persistence with denosumab in routine care. Persistence was defined as receiving seven denosumab injections, using an 8-week permissible gap, over 36 months. Non-persistent patients were further investigated retrospectively to identify reasons for discontinuation, when available. RESULTS: Demographic analysis showed a population of 1158 patients with mean age 68.4 years old and baseline T-score - 2.7; nearly half of which experienced a prior osteoporosis-related fracture. In a Kaplan-Meier survival analysis, 36-month persistence overall was 50.7%. Net persistence, as defined by receiving seven injections in the allowable time frame, was 64.2% of the cohort. In a multivariate analysis, prior vertebral fractures and recent osteoporosis therapy were associated with higher persistence; age greater than 75 years was associated with non-persistence. Reasons for discontinuation were available in 91.6% of non-persistent patients and categorized to include the ten most common explanations. CONCLUSION: This study to our knowledge represents the longest continuous observational period providing data on denosumab persistence in a real-world setting. The total persistence noted is quite robust when compared to bisphosphonates and is within the upper range of prior published studies of denosumab with shorter observation periods.

Patients with prior vertebral or hip fractures treated with teriparatide in the Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) observational study.

SUMMARY: In patients in the Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) observational study with and without a prior vertebral or hip fracture, the incidence of nonvertebral fractures was lower with >6 months of teriparatide treatment than during the first 6 months. INTRODUCTION: Clinical evidence on the effect of teriparatide in patients with prior fracture is limited. In the DANCE observational study, the incidence of nonvertebral fragility fractures (NVFX) decreased significantly in patients receiving teriparatide for >6 months (6-24 months) versus >0 to ≤6 months (reference period). METHODS: We performed a post hoc analysis to assess the effect of teriparatide 20 µg/day in patients who entered DANCE with prior vertebral or hip fractures. The incidence of patients experiencing a NVFX for four 6-month intervals during and after treatment was compared with the reference period. RESULTS: Overall, 4085 patients received ≥1 dose of teriparatide. Of 3720 with sufficient data for efficacy analysis, 692 had prior vertebral fracture, including 179 with previous kyphoplasty/vertebroplasty; 290 had prior hip fracture. These patients were older, and those with prior vertebral fractures had more comorbid conditions at baseline than those without prior vertebral fractures. The incidence of patients experiencing NVFX declined over time in all patient groups. The fracture incidence rate declined 49 and 46%, respectively, in patients with and without prior vertebral fracture and was 63 and 46% lower in patients with previous kyphoplasty/vertebroplasty and without prior vertebral fracture. NVFX declined 43 and 48% in patients with and without prior hip fracture. The reduced incidence over time was consistent in the subgroups (all interaction p values >0.05). Patients with prior fracture were more likely to experience serious adverse events. CONCLUSION: The incidence of NVFX decreased over time in patients receiving teriparatide in DANCE regardless of prior fracture status.

Successful treatment of sternal fracture nonunion with teriparatide.

SUMMARY: Fractures have a significant impact on the quality of life for the patient in addition to an enormous indirect cost in lost productivity for our economy. While majority of fractures heal uneventfully, some fail to heal even after many months resulting in nonunion. INTRODUCTION: Sternal nonunions, although rare, are particularly onerous for the patient given the magnitude of impact on quality of life. METHODS: Current treatment for fracture nonunions emphasizes various approaches to surgical fixation in addition to bone grafting. These treatments are aggressive and have a variety of drawbacks, rendering them suboptimal as a therapeutic approach. CONCLUSION: Based on the success of teriparatide in animal studies to accelerate fracture healing, there is growing interest in using this drug in humans for the same purpose. We report a case of what we believe to be the first successful use of teriparatide in the healing of a sternal nonunion fracture.

Synovial procollagenase activation by human mast cell tryptase dependence upon matrix metalloproteinase 3 activation.

Mast cells have been implicated in the pathogenesis of the matrix degradation observed in the cartilaginous and osseous structures of the rheumatoid joint. We previously reported that human mast cell tryptase, a 134-kD granule-associated neutral protease, is present in rheumatoid synovium and can activate collagenase in crude culture medium in vitro. the present study attempts to depict the precise mechanism of this activation. To express full activation of latent collagenase, matrix metalloproteinase 3 (MMP-3) or stromelysin, can be activated by tryptase in a time and dose-dependent manner. Tryptase was not capable of generating active collagenase in the crude media from cultured rheumatoid synoviocytes depleted of proMMP-3 by immunoadsorption. In addition, the function of the tissue inhibitor of metalloproteinases (TIMP) was not altered by tryptase, and SDS-PAGE analysis revealed no degradation of TIMP by tryptase. The tryptase dependent activation of synoviocyte procollagenase thereby appears to be entirely dependent upon its ability to activate proMMP-3.

Human mast cells stimulate vascular tube formation. Tryptase is a novel, potent angiogenic factor.

The presence of mast cells near capillary sprouting sites suggests an association between mast cells and angiogenesis. However, the role of mast cells in blood vessel development remains to be defined. In an attempt to elucidate this relationship, we investigated the effect of human mast cells (HMC-1) and their products on human dermal microvascular endothelial cell (HDMEC) tube formation. Coculture of HMC-1 with HDMEC led to a dose-response increase in the network area of vascular tube growth. Moreover, the extent of neovascularization was enhanced greatly when HMC-1 were degranulated in the presence of HDMEC. Further examination using antagonists to various mast cell products revealed a blunted response (73-88% decrease) in the area of vascular tube formation if specific inhibitors of tryptase were present. Tryptase (3 microg/ml) directly added to HDMEC caused a significant augmentation of capillary growth, which was suppressed by specific tryptase inhibitors. Tryptase also directly induced cell proliferation of HDMEC in a dose-dependent fashion (2 pM-2 nM). Our results suggest that mast cells act at sites of new vessel formation by secreting tryptase, which then functions as a potent and previously unrecognized angiogenic factor.

The differentiation and function of myofibroblasts is regulated by mast cell mediators.

Myofibroblasts are fibroblasts that express certain features of smooth muscle differentiation. Increased numbers of myofibroblasts and mast cells are frequently found together in a wide variety of settings, such as normal wound repair and scleroderma skin, which suggests that mediators produced by the mast cells could play a role in the regulation of myofibroblast differentiation and function. We used a human mast cell line, HMC-1, to determine if mast cells can induce normal human dermal fibroblasts to differentiate into functional myofibroblasts in vitro. We monitored the differentiation process by assaying two properties of the myofibroblast phenotype: expression of alpha-smooth muscle actin and functional capacity to contract a collagen matrix. In both a simple coculture system and in a skin-equivalent culture system, HMC-1 cells induced alpha-smooth muscle actin expression by fibroblasts. HMC-1 cells also stimulated fibroblast contraction of collagen gels, and the relative amount of contraction was dependent upon the number of HMC-1 cells present. To characterize the individual contributions made by specific mast cell products, we examined the effects of histamine, tumor necrosis factor alpha, and tryptase. Histamine induced a clear increase in alpha-smooth muscle actin expression, but it did not appear to stimulate fibroblast contraction. Tumor necrosis factor alpha had no effect in either assay. Purified human tryptase induced alpha-smooth muscle actin expression, and blocking the proteolytic activity of tryptase with specific inhibitors reduced that response. Tryptase inhibitors also eliminated the ability of HMC-1 cells to stimulate fibroblast contraction, suggesting that tryptase secreted by the HMC-1 cells may be one of the active mast cell mediators.

Prevalence and functional role of anti-IgE autoantibodies in urticarial syndromes.

The prevalence of autoantibodies of immunoglobulin G (IgG) and immunoglobulin M (IgM) classes directed against myeloma immunoglobulin E (IgE) were determined in distinct subsets of urticaria, using an enzyme immunoassay. IgG anti-IgE antibodies were found in five of nine patients (55%) with cold urticaria, four of eight patients (50%) with urticarial vasculitis, and three of six patients (50%) with chronic urticaria. IgM anti-IgE antibodies were found exclusively in cold urticaria (two of nine patients, 22%). Heating of these sera increased the binding to IgE, suggesting immune complex formation. Several positive sera were capable of inducing histamine release from normal peripheral basophils and caused a wheal-flare response upon intradermal injection. Sera containing such autoantibodies from three cold urticaria patients were studied for passive transfer of cold sensitivity. One serum containing IgG anti-IgE gave a strongly positive transfer test at 5 h but not 48 h, suggesting a pathogenic role for the IgG.

Mast cells induce T-cell adhesion to human fibroblasts by regulating intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression.

The capacity of mast cell products to mediate T-cell adhesion to fibroblasts was explored using heterotypic coculture systems or by exposing fibroblasts to mast-cell-conditioned media (MCCM), prepared by degranulating mast cells with calcium ionophore. Experimental results indicated that fibroblasts exposed to MCCM for 24 h bound fivefold more T cells than control fibroblasts. Binding was inhibited with intercellular adhesion molecule-1 (ICAM-1) or vascular cell adhesion molecule-1 (VCAM-1) neutralizing antibodies. Enzyme-linked immunosorbent assay and fluorescence-activated cell sorter analysis revealed that fibroblasts exposed to MCCM markedly increased ICAM-1 and VCAM-1 surface expression by 4 h, with levels maximal at 16 h and returning toward baseline by 48 h. A dose-dependent response of ICAM-1 and VCAM-1 expression was noted using serial dilutions of MCCM or by altering the ratio of degranulated mast cells cocultured with fibroblasts. Similar results were obtained using human fibroblasts derived from the dermis, synovium, and lung, although lung fibroblasts were generally less responsive. Northern analysis confirmed that MCCM regulated ICAM-1 and VCAM-1 expression at the mRNA level. In summary, mast cell products stimulated fibroblast surface expression, steady-state mRNA levels, and functional expression of ICAM-1 and VCAM-1. Experimental data suggest that mast-cell-derived tumor necrosis factor-alpha may be in large part responsible for these observations, although further studies using human mast cells will be required. Using a skin-equivalent organotypic coculture model with fibroblasts admixed with mast cells, we observed increased ICAM-1 expression in both keratinocytes and fibroblasts after activation of the mast cells.

L-tryptophan-associated eosinophilic perimyositis, neuritis, and fasciitis. A clinicopathologic and laboratory study of 25 patients.

We have described the spectrum and prevalence of the clinical and laboratory manifestations of a multisystem disorder associated with the ingestion of L-tryptophan. At least 3 subsets of clinical disease have been identified: 1) a neuromuscular disorder which may present with myalgias and mild weakness and then progress to quadriparesis related to an axonal neuropathy and interstitial myositis (perimyositis), 2) a syndrome of eosinophilic fasciitis with characteristic cutaneous induration, and 3) the Löffler syndrome consisting of pulmonary infiltrates with eosinophilia. Corticosteroids may be useful for patients with the Löffler syndrome and offer only a modest benefit in the majority of patients with neuromuscular disease. The clinical course appears to be chronic, and the long-term sequelae of this disorder are unknown. The etiologic agent remains undetermined; however, studies are in progress to examine the mechanism of eosinophilia, appropriate therapeutic intervention, and the long-term outcome of the affected individuals.

Effects of commonly prescribed nonsteroidal anti-inflammatory drugs on thyroid hormone measurements.

PURPOSE: To assess the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on thyroid function tests. PATIENTS AND METHODS: Eighty-nine patients receiving NSAIDs and 22 control subjects not taking NSAIDs were studied in a cross-sectional survey at Veterans Affairs and University hospitals. Measurements of serum thyroxine (T4), free T4 index, triiodothyronine (T3), and thyrotropin (thyroid-stimulating hormone [TSH]) were obtained for all subjects. RESULTS: Serum T4 measurements were lowered only in salsalate-treated patients, while serum T3 was depressed in patients receiving salsalate, diclofenac sodium, and naproxen. Serum T4 and T3 were unchanged in patients treated with diflunisal, ibuprofen, indomethacin, piroxicam, or sulindac. Serum TSH was normal in all subjects. CONCLUSIONS: Several NSAIDs can lower serum thyroid hormone concentrations, principally by interfering with the binding of T4 and T3 to serum carrier proteins; patients taking these drugs remain euthyroid. Awareness of these interactions may prevent unnecessary diagnostic or therapeutic interventions.

Immunoglobulin E, mast cells, endogenous antigens, and arthritis.

New aspects of the biology of the mast cell and its associated products may be important to the pathogenesis of arthritis. Mast cells may be activated in human arthritides as a result of a rapidly expanding list of peptides, including cytokines and neurotransmitters. The classic immunoglobulin E-coupled mast cell activation pathways may be used in the autoimmune diseases by way of autoantibody production involving the immunoglobulin E molecule itself. This can be shown to induce mediator release in vitro. The mast cell-derived products may play a role in both the early phases of synovitis as well as the chronic destructive phase.

Fibrogenic growth factors in the eosinophilia-myalgia syndrome and the toxic oil syndrome.

BACKGROUND AND DESIGN: We sought to determine if growth factors of potential pathogenetic significance are deposited in the skin, muscle, and peripheral nerve lesions of eosinophilia-myalgia (EMS) and toxic oil syndrome. Immunohistochemical studies using affinity-purified peroxidase-conjugated antibodies to detect transforming growth factor-beta, platelet-derived growth factorAA and growth factorBB, fibroblast growth factor, epidermal growth factor, and interleukin 4 were performed on formalin-fixed, paraffin-embedded specimens. Seven skin biopsy specimens from EMS, six skin biopsy specimens from toxic oil syndrome, nine muscle biopsy specimens from EMS, and one sural nerve biopsy specimen from EMS were studied. RESULTS: Growth factor staining was noted primarily in the epidermis and periappendageal locations of the dermis. The presence of TGF-beta and platelet-derived growth factorAA in the periappendageal dermis was significantly more prevalent in EMS than toxic oil syndrome (57% vs 0%). Prominent staining of transforming growth factor-beta was also present in the perimysial connective tissue of five (63%) of eight EMS muscle biopsy specimens and one sural nerve biopsy specimen. CONCLUSIONS: These studies implicate transforming growth factor-beta and platelet-derived growth factorAA as potentially important cytokines in EMS and suggest that the pathogenesis of tissue fibrosis in EMS and toxic oil syndrome may be dependent on different growth factors.

Growth factors in subglottic stenosis.

We sought to define the role of fibrogenic peptides in subglottic stenosis (SGS). Biopsy specimens were obtained from patients with stenosis following endotracheal intubation (group 1, n = 5, mean age 5), patients without a history of any precedent trauma, ie. idiopathic stenosis (group 2, n = 3, mean age 40), and those without stenosis (group 3, n = 3, mean age 70). Formalin-fixed biopsy specimens were analyzed following immunohistochemical staining to determine if epidermal growth factor (EGF), platelet-derived growth factor-AA and -BB (PDGF-AA/BB), transforming growth factor-beta 1 and -beta 2 (TGF-beta 1, beta 2), or basic fibroblast growth factor (bFGF) was deposited in these tissues. Blinded analysis revealed TGF-beta 2 and PDGF-AA to be present in seven of eight biopsy specimens from SGS and absent in controls. Staining for PDGF-BB was observed in the mucosa and submucosa and occasionally within vessel walls. Staining of individual growth factors appeared to correlate closely with the presence of granulation tissue. Essentially no bFGF or TGF-beta 1 was observed. Differences were found between patients in groups 1 and 2; tissue from group 1 revealed deposition of EGF and PDGF-BB in submucosa, epithelium, and vasculature. In summary, our experimental findings implicate PDGF and TGF-beta 2, perhaps acting in concert, in mediating the pathologic fibrotic process observed in subglottic stenosis. Epidermal growth factor, in conjunction with TGF-beta and PDGF, may also have a role, but further investigation is needed to more precisely define it.