IVIg therapy in autoimmunity and related disorders: our experience with a large cohort of patients

Intravenous immunoglobulin (IVIg) is used to treat a number of immune-deficiencies and autoimmune diseases. It has been shown that IVIg contains anti-idiotypic antibodies, which explains its immunomodulatory action.In murine models, recent investigations have demonstrated that IVIg can prevent and reduce the affliction by systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS) and scleroderma. Relevant disease-specific fractions of IVIg were able to reproduce and even enhance the therapeutic effect in a murine model.IVIg treatment before tumor resection in rodents inoculated with melanoma and sarcoma cells dramatically improved the cure rate (50%) in comparison to the control group (0%).In patients affected by SLE, several clinical manifestations responded to IVIg treatment including serositis, hematological manifestations, treatment-resistant nephritis and central nervous system involvement. Similarly, in women with recurrent fetal loss due to APS, IVIg was able to diminish the abortion rate. Vasculitides such as Churg-Strauss' and Wegener's and skin fibrosis in patients affected by scleroderma improved after IVIg treatment. In agreement with in vitro investigations, prolonged survival has been noted in cancer patients treated with IVIg.We suggest that in the presence of a steroid and immunosuppressive-resistant autoimmune disease, IVIg is a rational and safe choice.     

Spatial analysis of the distribution of Ixodes dammini (Acari: Ixodidae) on white-tailed deer in Ogle County, Illinois.

The pattern of infestations of Ixodes dammini on white-tailed deer in Ogle County in Illinois was studied through examinations of hunted deer from 1988 to 1990. The Illinois Geographic Information System mapped the spatial distribution of tick infestations on deer and related it to a known endemic focus for I. dammini and Borrelia burgdorferi (Castle Rock State Park), and to a major waterway (Rock River). Second-order neighborhood analysis was used to analyze the spatial distribution of deer around Castle Rock State Park. More than 25% of deer were infested. All deer were clustered around CRSP, but the clustering resulted mostly from clustering of infested deer around CRSP. CRSP is apparently the only important source of tick infestations in Ogle County. Clustering of infested deer did not change during the 3-yr study period. The dispersion pattern of ticks on deer was aggregated, with twice and three times as many ticks collected from bucks as from does and from fawns, respectively. More male ticks than female ticks were collected from infested deer. Of 59 ticks removed from harvested deer in 1990, 5.1% tested positive for B. burgdorferi.     

A founder truncating variant in GDF1 causes autosomal‐recessive right isomerism and associated congenital heart defects in multiplex Arab kindreds

The genetic basis of congenital heart malformations associated with disruption of left–right (L–R) asymmetry is broad and heterogenous, with variants in over 25 genes implicated thus far. Of these, deleterious variants in the Growth/Differentiation Factor 1 (GDF1) gene have been shown to cause heterotaxy with varied complex heart malformations of left–right patterning, in 23 individuals reported to date, either in monoallelic or biallelic state. We report three unrelated individuals exhibiting right isomerism with congenital heart defects, each originating from a consanguineous kindred of Arab‐Muslim descent. Using whole exome sequencing, a shared novel homozygous truncating c.608G > A (p.W203*) variant in the GDF1 gene was revealed as the molecular basis of their disease. Subsequently, targeted sequencing of this variant showed full segregation with the disease in these families, with a total of over 15 reportedly affected individuals, enabling genetic counseling, prenatal diagnosis, and planning of future pregnancies. Our findings further confirm the association of biallelic GDF1 variants, heterotaxy and congenital heart defects of left–right patterning, and expand the previously described phenotypic spectrum and mutational profile. Moreover, we suggest targeted screening for the p.W203* variant in relevant clinical circumstances.     

Obstetric outcome of in vitro fertilized pregnancies complicated by severe ovarian hyperstimulation syndrome: a multicenter study

Objective: To assess the outcome of pregnancies conceived with the use of IVF that are complicated by severe ovarian hyperstimulation syndrome (OHSS).

Design: A retrospective nationwide multicenter study.

Setting: Sixteen of 19 tertiary care medical centers in Israel.

Patient(s): All patients undergoing IVF who were hospitalized for severe OHSS between January 1987 and December 1996.

Main Outcome Measure(s): Pregnancy rate (PR) and rates of multiple gestation, miscarriage, ectopic pregnancy, obstetric complications, and intervention.

Result(s): A total of 163 patients who had severe OHSS after IVF treatment were identified, of whom 142 (87.1%) had undergone ET. The clinical PR was 73.2%; 42.3% were singletons, 33.6% were twins, 17.3% were triplets, and 6.7% were quadruplets. The miscarriage rate was 29.8%, whereas the incidence of ectopic pregnancy was 1.9%. Forty-four percent of all births were premature, and 62.1% of all newborns had low birth weight. The most common antenatal complications were pregnancy-induced hypertension (13.2%), gestational diabetes (5.9%), and placental abruption (4.4%). The rate of cesarean section was 44.1%.

Conclusion(s): Among patients who have severe OHSS after IVF treatment, the pregnancy rate and the rates of multiple gestation, miscarriage, prematurity, low birth weight, pregnancy-induced hypertension, gestational diabetes, and placental abruption are significantly higher than those reported previously for pregnancies conceived with the use of assisted reproductive techniques.     

The Antifungal Itraconazole Is a Potent Inhibitor of Chikungunya Virus Replication

Chikungunya virus (CHIKV) is the causative agent of chikungunya fever, a disabling disease that can cause long-term severe arthritis. Since the last large CHIKV outbreak in 2015, the reemergence of the virus represents a serious public health concern. The morbidity associated with viral infection emphasizes the need for the development of specific anti-CHIKV drugs. Herein, we describe the development and characterization of a CHIKV reporter replicon cell line and its use in replicon-based screenings. We tested 960 compounds from MMV/DNDi Open Box libraries and identified four candidates with interesting antiviral activities, which were confirmed in viral infection assays employing CHIKV-nanoluc and BHK-21 cells. The most noteworthy compound identified was itraconazole (ITZ), an orally available, safe, and cheap antifungal, that showed high selectivity indexes of >312 and >294 in both replicon-based and viral infection assays, respectively. The antiviral activity of this molecule has been described against positive-sense single stranded RNA viruses (+ssRNA) and was related to cholesterol metabolism that could affect the formation of the replication organelles. Although its precise mechanism of action against CHIKV still needs to be elucidated, our results demonstrate that ITZ is a potent inhibitor of the viral replication that could be repurposed as a broad-spectrum antiviral.     

Dromedary camel nanobodies broadly neutralize SARS-CoV-2 variants

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike is a trimer of S1/S2 heterodimers with three receptor-binding domains (RBDs) at the S1 subunit for human angiotensin-converting enzyme 2 (hACE2). Due to their small size, nanobodies can recognize protein cavities that are not accessible to conventional antibodies. To isolate high-affinity nanobodies, large libraries with great diversity are highly desirable. Dromedary camels (Camelus dromedarius) are natural reservoirs of coronaviruses like Middle East respiratory syndrome CoV (MERS-CoV) that are transmitted to humans. Here, we built large dromedary camel V_HH phage libraries to isolate nanobodies that broadly neutralize SARS-CoV-2 variants. We isolated two V_HH nanobodies, NCI-CoV-7A3 (7A3) and NCI-CoV-8A2 (8A2), which have a high affinity for the RBD via targeting nonoverlapping epitopes and show broad neutralization activity against SARS-CoV-2 and its emerging variants of concern. Cryoelectron microscopy (cryo-EM) complex structures revealed that 8A2 binds the RBD in its up mode with a long CDR3 loop directly involved in the ACE2 binding residues and that 7A3 targets a deeply buried region that uniquely extends from the S1 subunit to the apex of the S2 subunit regardless of the conformational state of the RBD. At a dose of ≥5 mg/kg, 7A3 efficiently protected transgenic mice expressing hACE2 from the lethal challenge of variants B.1.351 or B.1.617.2, suggesting its therapeutic use against COVID-19 variants. The dromedary camel V_HH phage libraries could be helpful as a unique platform ready for quickly isolating potent nanobodies against future emerging viruses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of COVID-19 (1, 2) that enters human cells by binding its envelope anchored type I fusion protein (spike) to angiotensin-converting enzyme 2 (ACE2) (3, 4). The SARS-CoV-2 spike is a trimer of S1/S2 heterodimers with three ACE2 receptor-binding domains (RBDs) attached to the distal end of the spike via a hinge region that allows conformational flexibility (4). In the all-down conformation, the RBDs are packed with their long axes contained in a plane perpendicular to the axis of symmetry of the trimer. Transition to the roughly perpendicular up conformation exposes the receptor-binding motif (RBM), located at the distal end of the RBD, which is sterically occluded in the down state. Numerous neutralizing antibodies targeting the spike, particularly its RBD, have been developed to treat COVID-19 using common strategies such as single B cell cloning, animal immunization, and phage display (5–9). Most vaccines, including those that are messenger RNA based, are designed to induce immunity against the spike or RBD (10–12). However, emerging SARS-CoV-2 variants such as D614G, B.1.1.7 (Alpha, United Kingdom), B.1.351 (Beta, South Africa), and P.1 (Gamma, Brazil) have exhibited increased resistance to neutralization by monoclonal antibodies or postvaccination sera elicited by the COVID-19 vaccines (13, 14). Monoclonal antibodies with Emergency Use Authorization for COVID-19 treatment partially (Casirivimab) or completely (Bamlanivimab) failed to inhibit the B.1.351 and P.1 variants. Similarly, these variants were less effectively inhibited by convalescent plasma and sera from individuals vaccinated with a COVID-19 vaccine (BNT162b2) (13). The B.1.617.2 (Delta, India) variant became the prevailing strain in many countries (15). Highly effective and broadly neutralizing antibody therapy is urgently demanded for COVID-19 patients.Due to their small size and unique conformations, camelid V_HH single-domain antibodies (also known as nanobodies) can recognize protein cavities that are not accessible to conventional antibodies (16). To isolate high-affinity nanobodies without a need for further affinity maturation, it is highly desirable to construct large nanobody libraries with great diversity. Dromedary camels have been found as potential natural reservoirs of Middle East respiratory syndrome CoV (MERS-CoV) (17). We speculated that dromedary camels would be an ideal source of neutralizing nanobodies against coronaviruses. In the present study, we built large camel V_HH single-domain antibody phage libraries with a diversity of over 10¹¹ from six dromedary camels (Camelus dromedarius), three males and three females, with ages ranging from 3 mo to 20 y. We used both the SARS-CoV-2 RBD and the stabilized spike ectodomain trimer protein as baits to conduct phage panning for nanobody screening. Among all the binders, we found NCI-CoV-7A3 (7A3), NCI-CoV-1B5 (1B5), NCI-CoV-8A2 (8A2), and NCI-CoV-2F7 (2F7) to be potent ACE2 blockers. In addition, these dromedary camel nanobodies displayed potent neutralization activity against the B.1.351 and B.1.1.7 variants and the original strain (Wuhan-Hu-1). The cryoelectron microscopy (cryo-EM) structure of the spike trimer protein complex with these V_HH nanobodies revealed two distinct nonoverlapping epitopes for neutralizing SARS-CoV-2. In particular, 7A3 recognizes a unique and deeply buried region that extends to the apex of the S2 subunit of the spike. Combined treatment with 7A3 and 8A2 shows more potent protection against various variants in culture and mice infected with the B.1.351 variant. Interestingly, 7A3 alone retains its neutralization activity against the lethal challenge of the B.1.617.2 variant in mice.