The programed death-1 (PD1)/programed death-ligand 1 (PD-L1) pathway plays a critical role in balancing immunity and host immunopathology. During chronic HIV/SIV infection, there is persistent immune ...activation accompanied by accumulation of virus-specific cells with terminally differentiated phenotypes and expression of regulatory receptors such as PD1. These observations led us to hypothesize that the PD1/PD-L1 pathway contributes to the functional dysregulation and ineffective viral control, and its blockade may be a potential immunotherapeutic target.
Lymph node biopsies from HIV-infected patients (n = 23) were studied for expression of PD1 and PD-L1. In addition, we assessed the safety and biological activity of a human anti-PD-L1 antibody (Avelumab) in chronically SIV-infected rhesus macaques.
PD-L1 expression was observed in cells with myloid/macrophage morphology in HIV-infected lymph nodes. Administration of anti-PD-L1 was well tolerated, and no changes in body weights, hematologic, or chemistry parameters were observed during the study. Blockade of PD-L1 led to a trend of transient viral control after discontinuation of treatment.
Administration of anti-PD-L1 in chronic SIV-infected rhesus macaques was well tolerated. Overall, these data warrant further investigation to assess the efficacy of anti-PD-L1 treatment on viral control in chronic SIV infection as a prelude to such therapy in humans.
To determine the relapse rate and outcome in patients with Wegener’s granulomatosis treated with daily cyclophosphamide and glucocorticoids to induce remission followed by methotrexate for remission ...maintenance.
We performed an open-label prospective study in 42 patients with active Wegener’s granulomatosis. All patients were treated with a standardized regimen. Outcomes were assessed using predetermined definitions based on clinical characteristics and pathologic, laboratory, and radiographic findings.
All patients achieved disease remission. The median time to remission was 3 months, and the median time to discontinuation of glucocorticoids was 8 months. During a median of 32 months of follow-up, 1 patient died (of a myocardial infarction not related to vasculitis). Two patients (5%) had to withdraw from the study because of medication toxicity. Twenty-two patients (52%) relapsed, with glomerulonephritis occurring in 16 patients. Of these 16 patients, 4 had an increase of >0.2 mg/dL in serum creatinine level. All 4 patients returned to their prior level of renal function with treatment. None of the 22 relapses met the criteria for severe disease.
The use of cyclophosphamide and glucocorticoids for induction and methotrexate for maintaining remission is an effective and well-tolerated therapeutic approach in patients with active Wegener’s granulomatosis.
Mixed cryoglobulinemia (MC) is the most common extrahepatic manifestation of chronic hepatitis C virus (HCV) infection. Although the formation of inflammation‐triggering immune complexes is driven by ...clonal expansions of autoreactive B cells, we found total B cell numbers paradoxically reduced in HCV‐infected patients with MC. HCV patients with MC (n = 17) also displayed a reduced number and a reduced frequency of naïve B cells compared with HCV‐infected patients without MC (n = 19), hepatitis B virus–infected patients (n = 10), and uninfected controls (n = 50). This was due to an increased sensitivity of naïve B cells to apoptosis resulting in a reduction in the size of the naïve B cell subset. In addition, 4‐fold expansion and skewing (lower T1/T2‐ratio) of the immature B cell subset was noted in MC patients, suggesting that apoptosis of naïve B cells triggered the release of B cell precursors from bone marrow in an attempt to maintain normal B cell numbers. Following treatment of MC with the B cell–depleting antibody rituximab, the size of all B cell subsets, the T1/T2‐ratio, and the cyroglobulin levels all normalized. Cryoglobulin levels correlated with in vivo proliferation of T2 B cells, suggesting a link between the skewing of the T1/T2 ratio and the formation of immune complexes. Conclusion: This study provides insight into the mechanisms maintaining B cell homeostasis in HCV‐induced MC and the ability of rituximab therapy to restore normal B cell compartments. (HEPATOLOGY 2012;56:1602–1610)
People living with HIV (PLWH) with multidrug-resistant (MDR) viruses have limited therapeutic options and present challenges regarding clinical management. Recent studies have shown that passive ...transfer of combination broadly neutralizing antibodies (bNAbs) against HIV and anti-domain 1 CD4 antibody UB-421 can sustain virologic suppression in PLWH in the absence of antiretroviral therapy (ART). Yet studies addressing the therapeutic potential of these antibodies and/or detailed characterization of immunologic and virologic parameters in PLWH with MDR HIV are lacking.
We examined levels of immune activation and exhaustion markers on CD8+ T cells and the intact HIV proviral DNA burden in 11 PLWH with MDR viruses. For comparison purposes, we included a control group consisting of 27 ART-naïve viremic PLWH. In addition, we determined the sensitivity of infectious viral isolates obtained from the participants against eight bNAbs (3BNC117, 10-1074, VRC01, VRC07, N6, 10E8, PGDM1400, and PGT121) and two anti-CD4 antibodies (ibalizumab and UB-421) using a TZM-bl-based neutralization/suppression assay.
The level of intact HIV proviral DNA was comparable between the two groups (P = 0.29). The levels of activation and exhaustion markers PD-1 (P = 0.0019), TIGIT (P = 0.0222), 2B4 (P = 0.0015), CD160 (P = 0.0015), and CD38+/HLA-DR+ (P = 0.0138) were significantly lower in the MDR group. The infectious viral isolates from each study participant with MDR HIV were resistant to at least 2 bNAbs; however, they were sensitive to at least one of the CD4-binding and non-CD4-binding site antibodies. The majority of participants had ibalizumab-sensitive viruses although the isolates from some participants showed reduced sensitivity to ibalizumab. Notably, none of the 93 viral isolates obtained from the participants were resistant to UB-421.
Our data suggest that combination therapy with HIV-specific bNAbs and/or UB-421 in the presence of optimized background therapy could potentially provide sustained virologic suppression in PLWH with MDR HIV. However, this therapeutic strategy needs to be evaluated in human clinical trials.
Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health.
Minimal data exist on pregnancy following recovery from Ebola in people of child-bearing potential (females aged roughly 18–45 years). The aim of this study was to assess viral persistence or ...reactivation in pregnancy, the frequency of placental transfer of anti-Ebola IgG antibodies, and pregnancy outcomes in this population.
In this observational cohort study, we studied self-reported pregnancies in two groups: seropositive people who had recovered from Ebola virus disease (seropositive group) and seronegative people who had close contact with people with Ebola (seronegative group). Participants had enrolled in the PREVAIL III longitudinal study and were exposed during the 2014–2016 Liberian Ebola outbreak. The primary outcome was pregnancy result. We assessed rates of livebirths and other pregnancy results in both study groups, and presence of Ebola RNA by PCR in samples of placenta, maternal and cord blood, breastmilk, and vaginal secretions from people who had recovered from Ebola who conceived a median of 14 months after acute Ebola virus disease. Mixed-model logistic regression evaluated associations between first-reported pregnancy outcome, age, and study group. Growth and neurodevelopment in the infants born to people in the seropositive group were assessed at 6-month intervals for 2 years. Data were accrued by PREVAIL III study staff.
1566 participants were enrolled between June 17, 2015, and Dec 14, 2017, of whom 639 became pregnant (215 seropositive, 424 seronegative) and 589 reported pregnancy outcomes (206 seropositive, 383 seronegative). 105 infants born to 98 mothers in the seropositive group were enrolled in the birth cohort. Ebola RNA was not detected in 205 samples of placenta, cord blood, or maternal blood taken at birth from 54 mothers in the seropositive group, nor in 367 vaginal swabs. Viral RNA was found in two of 354 longitudinal breastmilk samples. All but one of 57 infants born during these 54 births were seropositive for anti-Ebola antibodies. Neonates showed high concentrations of anti-Ebola IgG, which declined after 6 months. Odds of adverse pregnancy outcome among the two groups were indistinguishable (OR 1·13, 95% CI 0·71–1·79). Compared with WHO standards, infants born to those in the seropositive group had lower median weight and length, and larger median head circumference over 2 years. Compared with a cohort from the USA accrual of gross motor developmental milestones was similar, whereas attainment of pincer grasp and early vocalisation were mildly delayed.
The risks of Ebola virus reactivation in the peripartum and postpartum period and of adverse birth outcomes are low in those who have recovered from Ebola virus disease and become pregnant approximately 1 year after acute Ebola virus disease. The implication for clinical practice is that care of people who are pregnant and who have recovered from Ebola can be offered without risks to health-care providers or stigmatisation of the mothers and their offspring. The implication for prospective mothers is that safe pregnancies are entirely possible after recovery from Ebola.
National Institute of Allergy and Infectious Diseases and Liberia Ministry of Health.
Changes in CD4+ T-cell surface marker phenotype and antigen receptor (TCR) repertoire were examined during the course of HIV infection and following therapy. A preferential decline in naive CD4+ T ...cells was noted as disease progressed. Following protease inhibitor therapy, naive CD4+ T cells increased only if they were present before initiation of therapy. Disruptions of the CD4+ TCR repertoire were most prevalent in patients with the lowest CD4+ T-cell counts. Antiviral or IL-12 therapy-induced increases in CD4+ T-cell counts led to only minor changes in previously disrupted repertoires. Thus, CD4+ T-cell death mediated by HIV-1 infection may result in a preferential decline in the number of naive CD4+ T cells and disruptions of the CD4+ T-cell repertoire that are not immediately corrected by antiviral or immune-based therapies.
The pathogenesis of granulomatous inflammation is complex and involves a variety of mechanisms acting in concert to bring about an inflammatory lesion that is able to contain and destroy ...intracellular pathogens. While this process is crucial to host defense, it is also a two-edged sword in that excessive or inappropriate granulomatous inflammation results in considerable damage to normal tissue. In recent years, there has been significant progress in dissecting the immunologic events involved in granuloma formation and maintenance. A better understanding of these events will allow us to more precisely modulate the granulomatous inflammatory response to the benefit of patients with both infectious and autoimmune diseases.
Objective
To examine the safety of mycophenolate mofetil (MMF) for remission maintenance in patients with Wegener's granulomatosis (WG) who had been treated with daily cyclophosphamide (CYC) and ...glucocorticoids to induce remission.
Methods
Fourteen patients were treated for active WG using a standardized regimen of CYC and glucocorticoids for induction of remission and MMF for remission maintenance. Outcome was assessed using predetermined definitions based on clinical characteristics and pathologic, laboratory, and radiographic findings.
Results
Remission occurred in all 14 patients (100%) at a median time of 3 months. The median time to discontinuation of glucocorticoids was 8 months. No patients died during protocol treatment and 6 patients (43%) relapsed at a median of 10 months after achieving remission. MMF was well tolerated and no patients had to be withdrawn as a result of medication toxicity.
Conclusion
The use of CYC and glucocorticoids for induction of remission and MMF for remission maintenance was well tolerated, but disease relapses were observed.
A substantial proportion of persons who develop COVID-19 report persistent symptoms after acute illness. Various pathophysiologic mechanisms have been implicated in the pathogenesis of postacute ...sequelae of SARS-CoV-2 infection (PASC).
To characterize medical sequelae and persistent symptoms after recovery from COVID-19 in a cohort of disease survivors and controls.
Cohort study. (ClinicalTrials.gov: NCT04411147).
National Institutes of Health Clinical Center, Bethesda, Maryland.
Self-referred adults with laboratory-documented SARS-CoV-2 infection who were at least 6 weeks from symptom onset were enrolled regardless of presence of PASC. A control group comprised persons with no history of COVID-19 or serologic evidence of SARS-CoV-2 infection, recruited regardless of their current health status. Both groups were enrolled over the same period and from the same geographic area.
All participants had the same evaluations regardless of presence of symptoms, including physical examination, laboratory tests and questionnaires, cognitive function testing, and cardiopulmonary evaluation. A subset also underwent exploratory immunologic and virologic evaluations.
189 persons with laboratory-documented COVID-19 (12% of whom were hospitalized during acute illness) and 120 antibody-negative control participants were enrolled. At enrollment, symptoms consistent with PASC were reported by 55% of the COVID-19 cohort and 13% of control participants. Increased risk for PASC was noted in women and those with a history of anxiety disorder. Participants with findings meeting the definition of PASC reported lower quality of life on standardized testing. Abnormal findings on physical examination and diagnostic testing were uncommon. Neutralizing antibody levels to spike protein were negative in 27% of the unvaccinated COVID-19 cohort and none of the vaccinated COVID-19 cohort. Exploratory studies found no evidence of persistent viral infection, autoimmunity, or abnormal immune activation in participants with PASC.
Most participants with COVID-19 had mild to moderate acute illness that did not require hospitalization. The prevalence of reported PASC was likely overestimated in this cohort because persons with PASC may have been more motivated to enroll. The study did not capture PASC that resolved before enrollment.
A high burden of persistent symptoms was observed in persons after COVID-19. Extensive diagnostic evaluation revealed no specific cause of reported symptoms in most cases. Antibody levels were highly variable after COVID-19.
Division of Intramural Research, National Institute of Allergy and Infectious Diseases.
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