Inhibition of autoantibody binding to platelet glycoprotein IIb/IIIa by anti-idiotypic antibodies in intravenous gammaglobulin

Intravenous immunoglobulin (IVIgG) causes an acute rise in the platelet count in the majority of patients with chronic immune thrombocytopenic purpura (ITP) but the mechanism(s) of action is still unknown. We evaluated the ability of three different IVIgG preparations to inhibit the in vitro binding of autoantibody to platelet glycoprotein (GP) IIb/IIIa. ITP plasma, known to contain anti-GPIIb/IIIa antibodies, was incubated overnight with either IVIgG or bovine serum albumin (BSA) followed by measurement of the autoantibody titer. Binding of autoantibody from eight ITP patients was inhibited by IVIgG in proportion to the IVIgG concentration. Using 3.2% IVIgG, compatible with therapeutic concentrations expected in vivo, mean inhibition of autoantibody binding ranged from 20.2% to 41.3%. No inhibition by IVIgG of alloantibody binding to the same or different molecules was detected (five patients with anti-GPIIb/IIIa and two with anti-HLA alloantibodies). F(ab')2 fragments of IVIgG also inhibited the binding of both plasma autoantibodies and purified anti-GPIIb/IIIA autoantibodies prepared by elution from antigen affinity columns. A portion of the anti-idiotypic antibodies could be adsorbed from IVIgG using insolubilized, purified anti-GPIIb/IIIa autoantibody. These results show that IVIgG preparations from normal donors contain anti-idiotypic antibodies directed against idiotypes located on GPIIb/IIIa autoantibodies but do not have anti-idiotypes to platelet alloantibodies against the same or different molecules. The importance of these anti-idiotypic antibodies in the therapeutic response to IVIgG remains to be established.     

Social Anxiety Disorder Is Associated With PTSD Symptom Presentation: An Exploratory Study Within A Nationally Representative Sample

Posttraumatic stress disorder (PTSD) and social anxiety disorder (SAD) demonstrate a high degree of comorbidity (ranging from 14.8% to 46.0%); however, little is known about the nature of this association. Contemporary research has largely focused on treatment‐seeking or veteran samples, and may not generalize to the population as a whole. Large‐scale epidemiological studies are needed to fill existing gaps in the literature and to clarify this association for the general population. The current study examined whether the presence of comorbid SAD influenced PTSD symptom presentation. The rate of individual PTSD symptoms was investigated among individuals with PTSD and SAD in comparison to those with PTSD alone. Data were obtained from Wave 2 of the National Epidemiological Survey of Alcohol and Related Conditions, a large, nationally representative survey of American adults (n = 34,653). Analyses revealed elevated rates of PTSD symptoms among those with comorbid PTSD and SAD across all symptom clusters, with significant odds ratios ranging from 1.5 to 4.87. Adjusting for depression and other Axis I disorders did not substantially alter study findings. Results suggest that the presence of SAD is associated with differences in the expression of PTSD symptoms.     

Nurses’ engagement with power,voice and politics amidst restructuring efforts

Change is inevitable, and increasingly rapid and continuous in healthcare as organizations strive to adapt, improve and innovate. Organizational change challenges healthcare providers because it restructures how and when patient care delivery is provided, changing ways in which nurses must carry out their work. The aim of this doctoral study was to explore frontline nurses’ experiences of living with rapid and continuous organizational change. A critical hermeneutic approach was utilized. Participants described feeling voiceless, powerless and apolitical amidst rapid and continuous organizational changes which fuelled apathy, cynicism and disengagement from the organization. However, critical analysis of the data showed that nurses actively engaged with power, voice and politics through resistant and transgressive behaviours in micro‐ethical moments of practice. There is a need to reconceptualize the concepts of voice, power and politics in nursing as there is dissonance between nurses’ beliefs about these concepts and what they are enacting in practice. Recognizing their enactment of power, voice and political agency at the micro‐level may empower nurses. Empowerment would mitigate the high levels of reports of powerlessness experienced in practice during organizational changes.     

Depression in patients referred for psychiatric consultation A need for a new diagnosis

The authors analyzed 329 referrals for psychiatric consultation from medical and surgical wards. They found depression to be the most prevalent diagnosis (34%), with Major Depression being the most common DSM-III subtype (49%). Depression was predominant in the elderly (p<0.05), in women (p<0.05), and in patients with a high degree of psychosocial stressors (p<0.01). There were significant differences among the DSM-III subtypes of depression in some of these correlates. The authors emphasize the importance of DSM-III in differentiating among the subtypes of depression in referred patients but they suggest the need for a new diagnosis for depression in the physically ill.     

Caprine arthritis-encephalitis virus-infected goats can generate human immunodeficiency virus-gp120 cross-reactive antibodies(1)

Lentiviruses display surprisingly disparate clinical manifestations in their specific hosts, share complex genetic structures, and exhibit extensive diversity, particularly in their envelope genes. The envelope protein, gp135, of caprine arthritis-encephalitis virus (CAEV) has minimal primary sequence homology to gp120, the envelope protein of human immunodeficiency virus (HIV). Nevertheless, they bear certain similarities in that they both possess five variable regions, both are heavily glycosylated, and both share short sequence motifs. We establish a further relationship and demonstrate that some goats, infected with CAEV, possess gp135-specific antibodies which cross-react with gp120 from several HIV strains, provided the protein is expressed in insect cells. We show that, although the cross-reactivity of these immunoglobulins depends on the level of glycosylation, nevertheless, some antibodies recognize the protein epitopes on gp120, at least some of which are linear in character. Further characterization of this unexpected cross-reaction will define its potential therapeutic utility.