Scarcity of published studies on osteopetrosis reduce the ability to develop evidence-based guidelines for the management of these patients. Expert opinion-based guidelines for this rare condition are nevertheless important to enable improved care.

BackgroundThe current knowledge of immunological responses to schistosomiasis, a major tropical helminthic disease, is insufficient, and a better understanding of these responses would support vaccine development or therapies to control granuloma-associated immunopathology. CD4+ T cells play critical roles in both host immune responses against parasitic infection and immunopathology in schistosomiasis. The induction of T helper (Th)1, Th2 and T regulatory (Treg) cells and their roles in schistosome infections are well-illustrated. However, little in vivo data are available on the dynamics of Th17 cells, another important CD4+ T cell subset, after Schistosoma japonicum infection or whether these cells and their defining IL-17 cytokine mediate host protective responses early in infection.MethodologyLevels of Th17 and the other three CD4+ T cell subpopulations and the cytokines related to induction or repression of Th17 cell generation in different stages of S. japonicum infection were observed. Contrary to reported in vitro studies, our results showed that the Th17 cells were induced along with the Th1, Th2, Treg cells and the IFN-γ and IL-4 cytokines in S. japonicum infected mice. The results also suggested that S. japonicum egg antigens but not adult worm antigens preferentially induced Th17 cell generation. Furthermore, decreasing IL-17 with a neutralizing anti-IL-17 monoclonal antibody (mAb) increased schistosome-specific antibody levels and partial protection against S. japonicum infection in mice.ConclusionsOur study is the first to report the dynamics of Th17 cells during S. japonicum infection and indicate that Th17 cell differentiation results from the integrated impact of inducing and suppressive factors promoted by the parasite. Importantly, our findings suggest that lower IL-17 levels may result in favorable host protective responses. This study significantly contributes to the understanding of immunity to schistosomiasis and may aid in developing interventions to protect hosts from infection or restrain immunopathology.

Objectives: This study retrospectively compares the effectiveness of methylprednisolone to dexamethasone in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or COVID-19) requiring intensive care. Design: This is an institutional review board approved cohort study in patients with COVID-19 requiring intensive care unit (ICU) admission. Patients admitted and requiring oxygen supplementation were treated with no steroids, methylprednisolone, or dexamethasone. Setting: This study takes place in the ICU’s at a large, tertiary, public teaching hospital serving a primarily low-income community in urban Los Angeles. Patients: All eligible patients admitted to the ICU for COVID-19 respiratory failure from March 1 to July 31, 2020 were included in this study. Interventions: A total of 262 patients were grouped as receiving usual care (n = 75), methylprednisolone dosed at least at 1mg/kg/day for ≥ 3 days (n = 104), or dexamethasone dosed at least at 6 mg for ≥7 days (n = 83). Measurements and Main Results: All-cause mortality within 50 days of initial corticosteroid treatment as compared to usual care was calculated. The mortality effect was then stratified based on levels of respiratory support received by the patient. In this cohort of 262 patients with severe COVID-19, all-cause mortalities in the usual care, methylprednisolone, and dexamethasone groups were 41.3%, 16.4% and 26.5% at 50 days ( P < 0.01) respectively. In patients requiring mechanical ventilation, mortality was 42% lower in the methylprednisolone group than in the dexamethasone group (hazard ratio 0.48, 95% CI: 0.235-0.956, P = 0.0385). Conclusions: In COVID-19 patients requiring mechanical ventilation, sufficiently dosed methylprednisolone can lead to a further decreased mortality as compared to dexamethasone.

Chronic schistosome infection results in the suppression of host immune responses, allowing long-term schistosome survival and restricting pathology. Current theories suggest that Treg play an important role in this regulation. However, the mechanism of Treg induction during schistosome infection is still unknown. The aim of this study was to determine the mechanism behind the induction of CD4 1 CD25 1 T cells by Schistosoma japonicum HSP60 (SjHSP60)-derived peptide SJMHE1 as well as to elucidate the cellular and molecular basis for the induction of CD4 1 CD25 1 T cells during S. japonicum infection. Mice immunized with SJMHE1 or spleen and LN cells from naïve mice pretreated with SJMHE1 in vitro all displayed an increase in CD4 1 CD25 1 T-cell populations. Release of IL-10 and TGF-b by SJMHE1 stimulation may contribute to suppression. Adoptively transferred SJMHE1-induced CD4 1 CD25 1 T cells inhibited delayed-type hypersensitivity in BALB/c mice. Additionally, SJMHE1-treated APC were tolerogenic and induced CD4 1 cells to differentiate into suppressive CD4 1 CD25 1 Treg. Furthermore, our data support a role for TLR2 in SJMHE1-mediated CD4 1 CD25 1 Treg induction. These findings provide the basis for a more complete understanding of the S. japonicum-host interactions that contribute to host homeostatic mechanisms, preventing an excessive immune response.Key words: CD4 1 CD25 1 Treg . Immunomodulation . Schistosomes . SJMHE1 . TLR2 Supporting Information available online IntroductionImmune regulation associated with protective immunity is intricate and entails the effective elimination of the pathogen without causing serious damage to the host. Conversely, effective pathogens have developed multiple mechanisms for modulating or suppressing host immunity as survival and dissemination strategies. Therefore, during the course of an infection, a struggle between host defense mechanisms and the pathogen's immunomodulatory processes results in a complex interplay that may result in pathogen eradication or damage to the host (and persistence of the pathogen). One of the survival strategies used by pathogens involves the induction of immunosuppressive cell populations, e.g. Treg [1,2]. 3052The first observations suggesting that Treg induction occurs during infections with certain pathogens were made in mice infected with Bordetella pertussis [3] and in humans infected with HCV [4] or the nematode Onchocerca volvulus [5]. More recently, Treg induction has been described in chronic infections caused by Candida albicans [6], Mycobacterium tuberculosis [7], HIV [8], Leishmania major [9], Litomosoides sigmodontis [10], and Helicobacter pylori [11]. Treg induction has also been associated with Schistosome infection. Schistosomiasis is a major human disease primarily caused by one of the three species of Schistosome endemic to parts of Asia, South America, and Africa, i.e. S. mansoni, S. haematobium, and S. japonicum. Mortality rates resulting from these types of parasitic infections are second only to malaria. Chronic schis...