Catatonia-related adverse outcomes after long-acting injectable antipsychotics: Case series.

Due to a lack of controlled, prospective trials examining the pathophysiology and treatment of catatonia, current guidelines vary regarding how and when to best use antipsychotics in the presence of catatonia and what factors to consider in a thorough risk-benefit analysis. The literature is especially limited in describing the risks and benefits of using long-acting injectable antipsychotics in the presence of catatonia. We describe four cases where patients with preexisting catatonia received long-acting injectable first generation antipsychotics and experienced severe adverse effects (three experienced worsening of catatonia and one experienced neuroleptic malignant syndrome). The evidence base for managing comorbid catatonia and psychosis remains underdeveloped and inconsistent, but there are numerous known risk factors for adverse antipsychotic reactions, which we describe in relation to these cases. Finally, we present best practices to consider when managing comorbid psychosis and catatonia, especially when considering the use of long-acting injectable antipsychotics.

Characterization of plasmablasts in the blood of HIV-infected viremic individuals: evidence for nonspecific immune activation.

Terminal differentiation of B cells and hypergammaglobulinemia are hallmarks of B-cell hyperactivity in HIV disease. Plasmablasts are terminally differentiating B cells that circulate transiently in the blood following infection or vaccination; however, in HIV infection, they arise early and are maintained at abnormally high levels in viremic individuals. Here we show that only a small fraction of plasmablasts in the blood of viremic individuals is HIV specific. Assessment of plasmablast immunoglobulin isotype distribution revealed increased IgG(+) plasmablasts in early and most prominently during chronic HIV viremia, contrasting with a predominantly IgA(+) plasmablast profile in HIV-negative individuals or in aviremic HIV-infected individuals on treatment. Of note, IgG is the predominant immunoglobulin isotype of plasmablasts that arise transiently in the blood following parenteral immunization. Serum immunoglobulin levels were also elevated in HIV-infected viremic individuals, especially IgG, and correlated with levels of IgG(+) plasmablasts. Several soluble factors associated with immune activation were also increased in the sera of HIV-infected individuals, especially in viremic individuals, and correlated with serum immunoglobulin levels, particularly IgG. Thus, our data suggest that while plasmablasts in the blood may contribute to the HIV-specific immune response, the majority of these cells are not HIV specific and arise early, likely from indirect immune-activating effects of HIV replication, and reflect over time the effects of chronic antigenic stimulation. Such B-cell dysregulation may help explain why the antibody response is inadequate in HIV-infected individuals, even during early infection.

Humans with chronic granulomatous disease maintain humoral immunologic memory despite low frequencies of circulating memory B cells.

CD27(+) memory B cells are reduced in the blood of patients with chronic granulomatous disease (CGD) for reasons and consequences that remain unclear. Here we confirm not only decreased CD27(+) but also IgG(+) B cells in the blood of CGD patients compared with healthy donors (HDs). However, among IgG(+) B cells, the ratio of CD27(-) to CD27(+) was significantly higher in CGD patients compared with HDs. Similar to conventional memory B cells, CD27(-)IgG(+) B cells of CGD patients expressed activation markers and had undergone somatic hypermutation, albeit at levels lower than their CD27(+) counterparts. Functional analyses revealed slight reductions in frequencies of total IgG but not influenza-specific memory B-cell responses, as measured by Elispot in CGD patients compared with HDs. Serum IgG levels and influenza-specific antibodies were also normal in these CGD patients. Finally, we provide evidence that influenza-specific memory B cells can be present within the CD27(-)IgG(+) B-cell compartment. Together, these findings show that, despite reduced circulating CD27(+) memory B cells, CGD patients maintain an intact humoral immunologic memory, with potential contribution from CD27(-) B cells.

Attenuation of HIV-associated human B cell exhaustion by siRNA downregulation of inhibitory receptors.

Chronic immune activation in HIV-infected individuals leads to accumulation of exhausted tissue-like memory B cells. Exhausted lymphocytes display increased expression of multiple inhibitory receptors, which may contribute to the inefficiency of HIV-specific antibody responses. Here, we show that downregulation of B cell inhibitory receptors in primary human B cells led to increased tissue-like memory B cell proliferation and responsiveness against HIV. In human B cells, siRNA knockdown of 9 known and putative B cell inhibitory receptors led to enhanced B cell receptor-mediated (BCR-mediated) proliferation of tissue-like memory but not other B cell subpopulations. The strongest effects were observed with the putative inhibitory receptors Fc receptor-like-4 (FCRL4) and sialic acid-binding Ig-like lectin 6 (Siglec-6). Inhibitory receptor downregulation also led to increased levels of HIV-specific antibody-secreting cells and B cell-associated chemokines and cytokines. The absence of known ligands for FCRL4 and Siglec-6 suggests these receptors may regulate BCR signaling through their own constitutive or tonic signaling. Furthermore, the extent of FCLR4 knockdown effects on BCR-mediated proliferation varied depending on the costimulatory ligand, suggesting that inhibitory receptors may engage specific pathways in inhibiting B cell proliferation. These findings on HIV-associated B cell exhaustion define potential targets for reversing the deleterious effect of inhibitory receptors on immune responses against persistent viral infections.

Enhancing effects of adjuvanted 2009 pandemic H1N1 influenza A vaccine on memory B-cell responses in HIV-infected individuals.

OBJECTIVE: To assess the humoral immune response to low-dose AS03-adjuvanted and standard-dose nonadjuvanted 2009 pandemic H1N1 influenza A vaccine in HIV-infected aviremic individuals receiving antiretroviral therapy and in uninfected individuals. DESIGN: A three-arm study. SETTING: Two clinics: one at the National Institutes of Health in Bethesda, Maryland, USA; and the other at the Maple Leaf Medical Clinic in Toronto, Ontario, Canada. PARTICIPANTS: HIV-infected and HIV-uninfected adults. INTERVENTION: Single intramuscular 15 µg dose of the monovalent inactivated 2009 pandemic H1N1 influenza A vaccine without adjuvant or 3.75 µg dose of the same strain with adjuvant AS03. MAIN OUTCOMES: Immunogenicity, as measured by hemagglutination inhibition (HAI) antibody titers and vaccine-specific memory B-cell responses. RESULTS: A total of 74 participants were enrolled. Twenty-one HIV-infected individuals received the low-dose adjuvanted 2009 pandemic H1N1 influenza A vaccine. Twenty-nine HIV-infected and 24 HIV-uninfected individuals received the standard-dose nonadjuvanted vaccine. There were no significant differences in antibody responses at 9 weeks postvaccination among the three groups studied. However, the IgG memory B-cell response against the vaccine was significantly higher in the HIV-infected group that received the low-dose adjuvanted vaccine when compared to the HIV-infected and uninfected groups that received the standard-dose nonadjuvanted vaccine. Conclusions remained unchanged after regression adjustment for age, gender, CD4 T-cell count, and baseline HAI titer. CONCLUSION: These data suggest that adjuvants could be used to expand coverage through dose sparing and improve humoral immune responses in immunocompromised individuals.

B cells in early and chronic HIV infection: evidence for preservation of immune function associated with early initiation of antiretroviral therapy.

Characterization of lymphocytes including B cells during early versus chronic HIV infection is important for understanding the impact of chronic viremia on immune cell function. In this setting, we investigated B cells before and after reduction of HIV plasma viremia by antiretroviral therapy (ART). At baseline, peripheral blood B-cell counts were significantly lower in both early and chronic HIV-infected individuals compared with uninfected controls. Similar to CD4(+) but not CD8(+) T cells, B-cell numbers in both groups increased significantly after ART. At baseline, B cells of early HIV-infected individuals were composed of a higher percentage of plasmablasts and resting memory B cells compared with chronic HIV-infected individuals whose B cells were composed of a higher percentage of immature/transitional and exhausted B cells compared with their early infection counterparts. At 1 year after ART, the percentage of resting memory B cells remained higher in early compared with chronic HIV-infected individuals. This difference translated into a better functional profile in that memory B-cell responses to HIV and non-HIV antigens were superior in early- compared with chronic-treated HIV infected individuals. These findings provide new insights on B cells in HIV infection and how early initiation of ART may prevent irreversible immune system damage.