Effect of omalizumab on angioedema in H1 -antihistamine-resistant chronic spontaneous urticaria patients: results from X-ACT, a randomized controlled trial.

BACKGROUND: Chronic spontaneous urticaria (CSU) severely impacts quality of life (QoL), especially in patients with wheals and angioedema. Omalizumab is approved as add-on therapy for CSU patients; however, its effect on patients who are double-positive for wheals and angioedema has not been systematically studied. OBJECTIVE: The primary objective was to evaluate the efficacy of omalizumab vs placebo at week 28 using the Chronic Urticaria Quality of Life (CU-Q2oL) questionnaire. Number of angioedema-burdened days, time interval between successive angioedema episodes, disease activity, angioedema-specific and overall QoL impairment were secondary objectives. METHODS: X-ACT was a phase III, randomized, double-blind study conducted in 24 centres (Germany), which selectively included CSU patients with angioedema and wheals. Patients were randomized (1 : 1) to omalizumab 300 mg or placebo (every 4 weeks up to week 24) (ClinicalTrials.gov number: NCT01723072). RESULTS: Of the 91 patients randomized to omalizumab (n = 44) or placebo (n = 47) at baseline, 68 completed the 28-week treatment phase (omalizumab, 35; placebo, 33). Omalizumab was superior to placebo in improving CU-Q2oL scores at week 28 (P < 0.001). There was a threefold improvement in angioedema-burdened days/week with omalizumab (0.3) vs placebo (1.1). The median time to first recurrence of angioedema was 57-63 days with omalizumab and <5 days with placebo. Omalizumab significantly improved angioedema-specific QoL (P < 0.001). The adverse events reported are in line with the established safety profile of omalizumab. CONCLUSION: Omalizumab was an effective treatment option for patients with moderate-to-severe CSU symptoms and angioedema unresponsive to high doses of antihistamine treatment.

Infrared spectroscopy: shedding light on synovitis in patients with rheumatoid arthritis.

OBJECTIVES: It is difficult to determine the extent of synovial involvement early in the course of rheumatoid arthritis. A spectroscopic technique was used to characterize the synovium of the small finger joints in both early and late rheumatoid arthritis. This synovium was also compared against normal joints. METHODS: Near-infrared spectroscopy assesses the absorption of near-infrared light by specific joints, giving a characteristic "fingerprint" of the properties of the underlying tissues. Triple measurements by infrared spectroscopy were taken at the bilateral second and third metacarpophalangeal joints. Multivariate analysis was applied. RESULTS: Analysis was able to demonstrate relationships between the specific sources of spectral variation and joint tenderness or swelling as well as radiographic damage. Further use of multivariate analysis allowed recognition of the spectral patterns seen in early disease vs late rheumatoid arthritis and correct classification of over 74% of the joints. CONCLUSIONS: The spectral regions where differences occurred were in the absorption bands related to tissue oxygenation status, allowing the provocative implication that this technique could be detecting ischaemic changes within the joint. Near-infrared spectroscopy may thus be able to provide us with some information about the biochemical changes associated with synovitis.

Contact activation in shock caused by invasive group A Streptococcus pyogenes.

OBJECTIVES: The aim of this study was to characterize abnormalities of coagulation in mice with experimental, invasive group A, streptococcal shock, in an attempt to explain the prolongation of the activated partial thromboplastin time identified in patients with streptococcal toxic shock syndrome. DESIGN: A longitudinal descriptive animal model study of coagulation times and single coagulation factors in mice infected with Streptococcus pyogenes. This was followed by an experimental study to determine whether streptococci or streptococcal products could activate the human contact system in vitro. SETTING: University infectious diseases and hemostasis molecular biology laboratories. SUBJECTS: CD1 outbred mice. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Coagulation times, single factor assays, and bradykinin assays were conducted on murine plasma at different times after streptococcal infection and compared with uninfected mice. In experiments in which streptococcal products were co-incubated with human plasma, we compared coagulation times, single factor assays, and activities against a range of chromogenic substrates with control plasma. In a murine model of streptococcal necrotizing fasciitis, the activated partial thromboplastin times were significantly prolonged in infected mice compared with controls, whereas prothrombin times were normal, suggesting an isolated abnormality of the intrinsic pathway. Bleeding was not seen. Prolongation of activated partial thromboplastin time was associated with reduced factor XII and prekallikrein, whereas levels of factors VIII, IX, XI, and high molecular weight kininogen were elevated. In vitro studies suggested that streptococcal supernatants can activate prekallikrein, in addition to causing plasminogen activation through the action of streptokinase. CONCLUSIONS: Prolongation of activated partial thromboplastin time in streptococcal toxic shock syndrome is associated with activation of the contact system, possibly contributing to the profound shock associated with streptococcal toxic shock syndrome.

Anti-inflammatory therapy.

The inflammatory response involves a complex set of stereotyped biochemical and cellular reactions that aim to eliminate pathogens. Systemic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, feature a persistent, uncontrolled inflammatory response that typically culminates in tissue damage. The control of this inflammatory response is of paramount importance in preventing irreversible tissue damage, as well as in controlling symptoms. NSAIDs and corticosteroids are the most effective agents currently available to control the clinical manifestations of inflammation, although they usually need to be used in conjunction with other "disease modifying" strategies in order to achieve optimum control of chronic inflammatory disorders. As with all pharmacologic therapy, the risk to benefit ratio of each agent needs to be considered carefully before embarking on extended courses of therapy. Strategies to minimize the long-term risks of NSAIDs and corticosteroids are continuing to evolve and hold the promise of greater safety without loss of efficacy.

HLA associations of seropositive rheumatoid arthritis in a Cree and Ojibway population.

OBJECTIVE: To determine the HLA associations of seropositive rheumatoid arthritis (RA) in a Cree and Ojibway population; to determine whether specific alleles distinguish juvenile or adult onset. METHODS: HLA-A, B, C, and DRB1 alleles were analyzed in 23 Ojibway and Cree patients with RA seen in a single tertiary care center. Comparisons were made with published results of controls and with results of 18 patients with rheumatoid factor (RF) positive polyarticular juvenile rheumatoid arthritis (JRA) from the same population. RESULTS: Comparisons among patients with RA, patients with RF positive polyarticular JRA, and controls showed increased frequencies of the RA shared epitope in patients with RA and of DRB1*0901 in patients with seropositive polyarticular JRA, while the frequency of DRB1*08 alleles was decreased in patients with RF positive polyarticular JRA. CONCLUSION: In this population, DRB1*0901 may promote while DRB1*08 alleles may protect against a juvenile onset of RA specifically. In contrast, the RA shared epitope may have a greater effect on the risk of adult onset seropositive RA. Due to the small patient numbers, these results require confirmation.

Neuropsychiatric systemic lupus erythematosus and the syndrome of inappropriate secretion of antidiuretic hormone: a case report with very late onset systemic lupus erythematosus.

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with neuropsychiatric lupus (NP-SLE) is rare. We report a case of SIADH associated with the new onset of SLE in an 88-yr-old female. The unique features of this case include the extreme age of onset of SLE presenting with neuropsychiatric manifestations and positive antiribosomal P antibody titres. Both the NP manifestations of SLE and SIADH were highly correlated with the SLE disease activity. This case illustrates a novel presentation of NP-SLE with SIADH which may develop due to antibody-mediated hypothalamic dysfunction.

Rapid growth mutants of Escherichia coli.

If rapid growth (rap) mutants of Escherichia coli could be obtained, these might prove a valuable contribution to fields as diverse as growth rate control, biotechnology and the regulation of the bacterial cell cycle. To obtain rap mutants, a dnaQ mutator strain was grown for four and a half days continuously in batch culture. At the end of the selection period, there was no significant change in growth rate. The result means that selecting rap mutants may require an alternative strategy and a number of such alternatives are discussed.

Bacterial copper- and zinc-cofactored superoxide dismutase contributes to the pathogenesis of systemic salmonellosis.

Copper/zinc-cofactored superoxide dismutase ([Cu,Zn]-SOD) has been found in the periplasm of many bacterial species but its biological function is unknown. Here we report the cloning and characterization of sodC, encoding [Cu,Zn]-SOD, from Salmonella typhimurium. The predicted protein sequence shows only 58% identity to Escherichia coil SodC, and from this its chromosomal location and its immediate proximity to a phage gene, sodC, in Salmonella is speculated to have been acquired by bacteriophage-mediated horizontal transfer from an unknown donor. A sodC mutant of S. typhimurium was unimpaired on aerobic growth in rich medium but showed enhanced sensitivity in vitro to the microbicidal action of superoxide. S. typhimurium, S. choleraesuis and S. dublin sodC mutants showed reduced lethality in a mouse model of oral infection and persisted in significantly lower numbers in livers and spleens after intraperitoneal infection, suggesting that [Cu,Zn]-SOD plays a role in pathogenicity, protecting Salmonella against oxygen radical-mediated host defences. There was, however, no observable difference compared with wild type in the interaction of sodC mutants with porcine pleural, mouse peritoneal or J774 macrophages in vitro, perhaps reflecting the hierarchical capacity of different macrophage lines to kill Salmonella, the most efficient overwhelming the proposed protective effect of periplasmic SOD.

Artefactual cleavage of E coli H-NS by OmpT.

In the bacterium Escherichia coli, H-NS-(H1, H1a) is a heat-stable protein with a molecular mass of 15.5 kDa involved in nucleoid organisation and gene regulation linked to certain signal transduction pathways. We have shown that, following addition of preparations of everted inner membrane vesicles, heat-stable cleavage products of approximately 10 kDa of H-NS are formed in vitro from newly synthesised, radio-labelled H-NS and from purified H-NS. The 15.5 kDa protein and its cleavage products were also recovered from a minicell system. These results raised the possibility that cleavage of H-NS is physiologically significant. However, the cleavage of H-NS observed appears to occur during cell breakage and to depend on the method of protein extraction and the presence of the outer membrane protease, OmpT. Nevertheless, the results indicate that H-NS may contain at least two separate domains with cleavage occurring between these domains at a preferred OmpT site. Failure to take account of H-NS cleavage in sample preparation and analysis can lead to serious underestimation of H-NS levels.

Streptococcus pneumoniae produces a second haemolysin that is distinct from pneumolysin.

Pneumococci are described as alpha-haemolytic but under certain circumstances they produce zones of beta-haemolysis on blood-containing medium. This observation was investigated using wild type strains and a genetically-modified strain unable to produce the haemolytic toxin, pneumolysin. beta-haemolysis was produced by all pneumococci tested. It was not inhibited by anti-pneumolysin antibody but could be inactivated by cholesterol. These data confirm that pneumococci elaborate a second haemolysin, distinct from pneumolysin.

Persistence of Staphylococcus aureus as detected by polymerase chain reaction in the synovial fluid of a patient with septic arthritis.

Septic arthritis commonly occurs in the rheumatoid arthritis population. The diagnosis is frequently delayed and the associated mortality is high. In this brief report, we present a patient with rheumatoid arthritis and prosthetic knee joints who developed septic arthritis and had persisting evidence of Staphylococcus aureus DNA in synovial fluid, from his knees, which was detected by polymerase chain reaction (PCR) and a gene probe. This was detected until 10 weeks of therapy despite adequate antibiotic treatment and a sterile synovial fluid. In the future, it may be found that PCR of the synovial fluid will be a valuable investigation for the diagnosis and management of septic arthritis.

Synovial distribution of alpha d/CD18, a novel leukointegrin. Comparison with other integrins and their ligands.

OBJECTIVE: To define the synovial distribution of the novel leukointegrin alpha d/CD18, and compare this with other members of the beta 2-integrin family of adhesion molecules, and their counter-receptors. METHODS: Monoclonal antibodies to the CD3, CD14, CD29, CD68, beta 2-integrin, and immunoglobulin supergene families were used to immunohistologically define the distribution of these molecules in synovial tissue samples from normal subjects and osteoarthritis (OA) and rheumatoid arthritis (RA) patients. RESULTS: The normal synovial lining cell layer (SLC) expresses CD68, vascular cell adhesion molecule 1, beta 1-integrin (CD29), the beta 2-integrins CD11b/CD18 (alpha m/beta 2, Mac-1), and alpha d/CD18, whereas CD11a/CD18 (alpha L/beta 2, lymphocyte function-associated antigen 1) and CD11c/CD18 (alpha x/beta 2, gp150/95) expression is generally absent. In RA synovitis, expression of beta 2-integrins in the SLC increases in proportion to the degree of hyperplasia. The ratio of cells in the SLC which express CD11c/CD18 increases substantially, approaching that of CD11b/CD18 and alpha d/CD18, while there is minimal increase in CD11a/CD18 expression. In the sublining areas of the tissues, aggregates and diffuse infiltrates of CD3/CD11a/ICAM-3+ lymphocytes are interspersed among CD68/CD14/CD11b/alpha d+ macrophages. A number of aggregates demonstrate intense alpha d staining of the lymphocytes. The synovial endothelium variably expresses intercellular adhesion molecule-1 (ICAM-1), ICAM-2, and vascular cell adhesion molecule 1 (VCAM-1), with minimal evidence of ICAM-3 expression. CONCLUSION: The leukointegrin alpha d/CD18 is expressed constitutively by synovial macrophages and macrophage-like lining cells. In rheumatoid synovitis, the intense coexpression of this integrin and its known counter-receptor, ICAM-3, in the inflammatory infiltrates, suggests a potential role for this adhesion pathway in cellular interactions occurring the synovium.

Identification of sodC encoding periplasmic [Cu,Zn]-superoxide dismutase in Salmonella.

sodC, encoding [Cu,Zn]-cofactored superoxide dismutase, once thought to be virtually confined to eukaryotes, has now been described in many Gram-negative pathogens that have their primary niche of colonization in the upper respiratory tract. Their role in host-parasite interactive biology is unknown. We here show that members of the major human and animal enteric pathogenic species Salmonella harbour a version of sodC most closely resembling that found in Brucella abortus. The enzyme it encodes is a novel candidate determinant of virulence in Salmonella, an intracellular pathogen potentially exposed to toxic oxygen free radicals within its intracellular niche.