A Human Bi-specific Antibody against Zika Virus with High Therapeutic Potential.

Zika virus (ZIKV), a mosquito-borne flavivirus, causes devastating congenital birth defects. We isolated a human monoclonal antibody (mAb), ZKA190, that potently cross-neutralizes multi-lineage ZIKV strains. ZKA190 is highly effective in vivo in preventing morbidity and mortality of ZIKV-infected mice. NMR and cryo-electron microscopy show its binding to an exposed epitope on DIII of the E protein. ZKA190 Fab binds all 180 E protein copies, altering the virus quaternary arrangement and surface curvature. However, ZIKV escape mutants emerged in vitro and in vivo in the presence of ZKA190, as well as of other neutralizing mAbs. To counter this problem, we developed a bispecific antibody (FIT-1) comprising ZKA190 and a second mAb specific for DII of E protein. In addition to retaining high in vitro and in vivo potencies, FIT-1 robustly prevented viral escape, warranting its development as a ZIKV immunotherapy.

Accuracy of power Doppler ultrasonography in the diagnosis and monitoring of idiopathic inflammatory myopathies.

OBJECTIVES: No clear-cut guidelines exist for the use of imaging procedures for the diagnosis of idiopathic inflammatory myopathies (IIM). The aim of the present study was to assess the diagnostic accuracy of power Doppler ultrasonography (PDUS) score in IIM patients compared with a control group and its usefulness during follow-up. METHODS: All patients evaluated in the Vasculitis and Myositis Clinic, Rheumatology Unit, University of Siena were prospectively collected. All patients underwent US examination of both thighs in axial and longitudinal scans, which were also performed twice (T1) or three times (T2). RESULTS: Forty-five patients with IIM (median [interquartile range] age 55 [45-66] years; 35 female) were enrolled. Receiver operating characteristic curves distinguished patients and controls based on ∑power Doppler (PD), ∑oedema, ∑atrophy and CRP. The best cut-off value for ∑PD was 0.5, ∑oedema 1.5, ∑atrophy 0.5 and CRP 0.22 mg/dl. In a logistic regression analysis, the variables that most influenced diagnosis of IIM were ∑PD and ∑oedema (P = 0.017 and P = 0.013, respectively). ∑Oedema was lower at T1 (P = 0.0108) and T2 (P = 0.0012) than at T0. Likewise, ∑PD was lower at T1 (P = 0.0294) and T2 (P = 0.0420) than at T0. Physician global assessment was lower at T1 (P = 0.0349) and T2 (P = 0.0035) than at baseline. CONCLUSION: Our findings show that PDUS is a reliable diagnostic tool in the differential diagnosis between inflammatory and non-inflammatory myopathies. Moreover, PDUS can be employed also during the follow-up of patients with IIM. A reduction in disease activity, measured by physician global assessment, led to a concomitant decrease in both oedema and PD, which was directly correlated with their rate of change. This underlines the close link between clinical assessment and PDUS findings, not only at diagnosis but also during monitoring.

Effects of antiresorptive agents on body composition: a case-control retrospective study.

Introduction: Osteoporosis is the most represented metabolic bone disease and is characterized by the reduction of bone mineral density (BMD), exposing patients to high fracture risk and disability. Bisphosphonates (BPs) are the main compounds exploited in treatment of osteoporosis and significantly reduce fracture risk. Sarcopenia is the pathological reduction of muscle masses and strength, and many studies highlighted its co-existence in patients with impaired bone mass. Indeed, the pathological reduction of lean tissue has been linked to a higher risk of falls and, consequently, fractures and disability. Moreover, the pathological reduction of lean tissue seems to share many pathological mechanisms with impaired bone strength and structure; thus, in this context, we decided to conduct a retrospective case-control study aimed at evaluating the effects of BPs on lean mass and body composition. Material and methods: We enrolled postmenopausal women from our metabolic bone diseases outpatient clinic who underwent at least two consecutive dual-energy X-ray absorptiometry (DXA) examinations concomitantly to the beginning of an antiresorptive agent. The body composition of patients and controls was compared by fat masses, lean masses and android-to-gynoid ratio (A/G ratio). Results: A total of 64 female subjects were considered for the study: 41 starting a BPs and 23 without treatment were used as control. The fat masses and lean masses appeared to be unaffected by BPs. Conversely, A/G ratio was lower in BPs group after 18 months of therapy compared to baseline (p < 0.05). From the stratification based on the single BP we failed to highlight any significant difference between the tested variables. Conclusions: Bisphosphonates treatment did not modify lean tissues, however a significant reduction of A/G ratio in BP group was documented. Thus the BPs seems to act on patients body composition and extra-skeletal tissues but larger prospective studies are needed to evaluate whether these modifications have clinical relevance.

Diagnostic role of minor salivary glands biopsy in Sjögren's syndrome: correlations between histology and autoimmunity in a large, monocentric cohort.

Introduction: Based on ACR/EULAR classification criteria, minor salivary glands biopsy (MSGB) is a useful diagnostic tool for the diagnosis of primary Sjögren's syndrome (SS). The main objective of our study was to evaluate the diagnostic role of MSGB, as well as to highlight correlations between histological findings and autoimmune profiles. Material and methods: We retrospectively evaluated histological and autoimmunity data from patients who underwent MSGB in our department in cases of suspected SS, from March 2011 to December 2018. Salivary gland samples were evaluated using Chisholm and Mason (CM) grading and the focus score (FS). Results: A total of 1,264 patients (108 males, 1,156 females) were included. The median age was 55.22 ±13.51 years (range: 15-87). In univariate binary logistic regression, CM ≥ 3 and FS ≥ 1 were significantly predicted by antinuclear antibodies (ANA), anti-extractable nuclear antigens (ENA) and anti-Ro/SSA titer as well as anti-La/SSB, anti-Ro/SSA, rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) positivity. In multivariate analysis, CM ≥ 3 and MSGB positivity were significantly associated with ANA titer; FS ≥ 1 was not associated with laboratory findings. A positive biopsy was associated with laboratory findings, as ANA and ENA titers, anti-Ro/SSA, anti-La/SSB, RF and ACPA positivity may discriminate patients with SS-related histological findings. Conclusions: Minor salivary glands biopsy is a useful tool to diagnose SS in cases of highly suggestive clinical symptoms but in the absence of a specific autoimmunity.

Efficacy of intravenous neridronate in transient osteoporosis of the hip.

OBJECTIVES: To evaluate the efficacy and safety of intravenous (iv) neridronate in patients affected by transient osteoporosis of the hip (TOH). METHODS: We retrospectively evaluated the clinical records of patients affected by TOH treated with iv neridronate in our department. We treated patients with a value of visual analogue scale (VAS)-pain ≥ 80/100 mm at diagnosis, limited range of movement and magnetic resonance images (MRI) findings suggestive of TOH. The regimen used was: one iv infusion at day 0, 3, 6, 9 (100 mg for each infusion: total of 400 mg). This protocol was repeated in refractory cases. Recovery was defined as VAS-pain level ≤20/100. Concomitant use of analgesics was allowed. Paired Student t-test was used to assess VAS-pain change. RESULTS: Five patients were male, 3 were female. Mean age was 54.5±2.12 years old. Mean body mass index was 26.57±2.22. Mean time to diagnosis, since the onset of the symptoms, was 75±21.21 days. Mean number of neridronate infusions was 7.5±2.56. Mean time of recovery was 57±45.96 days. Mean VAS-pain at baseline was 84±2,24. Mean VAS-pain after treatment was significantly reduced (p<0.001) with a value of 12.12±6.46. None of the patients needed analgesics after treatment. No adverse event was reported. In 5 cases, post-treatment MRI showed complete bone marrow oedema resolution. CONCLUSIONS: Intravenous neridronate is effective and safe in the treatment of TOH and its use may lead to a faster resolution of the disease.

Routine IgG4 staining in minor salivary gland biopsy in a cohort of Italian Caucasian patients suffering from xerostomia.

Objectives: IgG4-related disease is a potentially systemic disease mimicking and overlapping with different autoimmune diseases, such as primary Sjögren's syndrome (pSS). The involvement of salivary glands, previously called Mikulicz's disease, has been reclassified as IgG4-related sialadenitis (SA). The aim of this study was to assess the prevalence of IgG4-SA in a cohort of Italian Caucasian patients presenting with xerostomia and to evaluate the eventual overlap between IgG4-SA and pSS. Material and methods: We included 154 patients - 15 males and 139 females, mean age 54.18 ±14.24 years, who underwent minor salivary gland biopsy between March and December 2019 for xerostomia. Histopathology was evaluated using Chisholm-Mason (CM) and focus score (FS) for pSS and immunohistochemical study with IgG4 staining for IgG4-SA were performed. Serum autoantibodies (anti-SSa/RoAb, anti-SSB/LaAb, antinuclear antibodies, rheumatoid factor) were also assessed. Results: In 69 patients (44.8%) FS 0 was found, while FS ≥ 1 was presented in 85 (55.2%). Chisholm-Mason score < 3 and CM ≥ 3 was found in 73 (47.4%) and 81 (52.6%) cases, respectively. IgG4/high-power field level was 20 in 3 pSS patients (1.9%), but none of them had an IgG4/IgG ratio ≥ 40, as well as tissue fibrosis with storiform pattern, obliterative vasculitis, and tissue eosinophilia. The diagnosis of pSS, was confirmed in 92 patients (59.74%). No patient was definitively diagnosed with an IgG4-related disease. Conclusions: In the case of xerostomia, the evaluation of the histopathological specimen for IgG4 should not be routinely performed, at least in an Italian-based Caucasian population. Moreover, immunohistochemistry should not be requested in the case of a negative result of biopsy for pSS.

Bone-sparing effects of tocilizumab in rheumatoid arthritis: a monocentric observational study.

Introduction: Bone loss is a common feature in several autoimmune and chronic inflammatory diseases, such as rheumatoid arthritis (RA). Indeed, the high levels of pro-inflammatory cytokines seem to enhance bone resorption and to diminish bone formation, thus producing an uncoupling between osteoclast and osteoblast function and favoring the onset of juxtarticular as well as systemic osteoporosis. Many papers underline the high prevalence of osteoporosis in RA, as well as the negative correlation between interleukin 6 (IL-6) serum levels and bone mineral density (BMD). The aim of this study was to assess the effectiveness of one-year treatment with tocilizumab (TCZ), the first approved IL-6 receptor inhibitor, in reducing bone loss in RA. Material and methods: We enrolled 18 patients fulfilling 2010 ACR and EULAR criteria for RA from our arthritis outpatient clinic, assessing clinical and biochemical parameters during a 12-month period. The patients received TCZ 8 mg/kg i.v. every 4 weeks and underwent dual energy X-ray absorptiometry (DXA) for the measurement of bone mineral density (BMD) at baseline and at the end of study. Serum levels of C-reactive protein (CRP), erythrocytes sedimentation rate (ESR), IL-6, serum CrossLaps, osteoprotegerin (OPG), receptor activator of nuclear factor κß ligand (RANK-L) and dickkopf-1 (DKK-1) were measured at baseline, at 6 months and 1 year. Results: No significant difference in IL-6, RANK-L, DKK-1, OPG and serum CrossLaps levels between baseline, 6 months and 1 year were found. A significant increase of lumbar spine BMD was evidenced after 1 year of TCZ treatment. No difference in total body and femoral neck BMD was documented the end of the study. Conclusions: This study suggest the bone-sparing effect of TCZ in RA affected individuals.

A novel grey scale and Power Doppler ultrasonographic score for idiopathic inflammatory myopathies: Siena Myositis Ultrasound Grading Scale.

OBJECTIVES: No clear-cut guidelines exist on the use of diagnostic procedures for idiopathic inflammatory myopathies (IIM) and only minimal and conflicting data report the use of ultrasound (US). In this regard, we aimed to assess if grey-scale (GS) and Power Doppler (PD) US, graded with a 0-3-point scale, may be a reliable tool in a cohort of patients affected by IIM. METHODS: All patients underwent US examination of both thighs in axial and longitudinal scans. Oedema and atrophy, both assessed in GS and PD, were graded with a 0-3-point scale. Spearman's test was used to identify the correlations between US and clinical and serological variables. RESULTS: A total of 20 patients were included. Six and two patients were evaluated twice and three times, respectively. Muscle oedema was found to be directly correlated with physician global assessment (PhGA), serum myoglobin and PD and negatively with disease duration. PD score was positively correlated to PhGA and negatively to disease duration. Muscle atrophy directly correlated with Myositis Damage Index, disease duration and patient's age. The single-thigh sub-analysis evidenced a direct correlation between PD score and Manual Muscle Test. CONCLUSIONS: In our cohort, we found that oedema and PD are strictly related to early, active myositis, suggesting that an inflamed muscle should appear swollen, thickened and with Doppler signal. Conversely, muscle atrophy reflects the age of the patient and the overall severity of the disease. Such findings shed a new, promising, light on the role of US in diagnosis and monitoring of IIMs.

Power and spectral Doppler ultrasound in suspected active sacroiliitis: a comparison with magnetic resonance imaging as gold standard.

OBJECTIVES: The objectives of this study were to study with Power Doppler US (PDUS) the SI joints (SIJs) of patients with suspected active sacroiliitis, to describe SIJ flows with spectral wave analysis (SWA) on Doppler US, and to correlate US data with both clinical characteristics and presence of SIJ bone marrow oedema (BME) in subsequent MRI. METHODS: A total of 42 patients (32 females and 10 males, mean age 46.8 years) with recent onset of inflammatory back pain (IBP) were included. Every patient underwent US examination with a convex 1-8 MHz probe [scoring PDUS signals with a three-point scale and describing flows in SWA calculating the mean Resistive Index (RI)] and subsequent MRI of the SIJs. RESULTS: PDUS signals were detected in 34 patients and 62 SIJs. In 29 patients and 56 SIJs, MRI revealed BME. A definite diagnosis of SpA was made in 32 patients. PDUS signals were more frequent (P < 0.0001) in patients with a final diagnosis of SpA, yielding a higher PDUS score (P = 0.0304). PDUS grading correlated with both BME grading (r = 0.740, P = 0.0001) and AS DAS (ASDAS) (r = 0.6257, P = 0.0004), but not with inflammatory reactants nor anthropometric data. Mean RI were, respectively, 0.60 and 0.73 (P < 0.0001) in patients with or without diagnosis of active sacroiliitis. The most inclusive RI cut-off resulted <0.70 [positive predictive value (PPV) 94%, accuracy 90%, P = 0.0001]. The best Likelihood Ratio (5.471) for RI to detect pathologic cases was obtained with a cut-off of <0.60 (PPV 96%). CONCLUSIONS: PDUS and SWA of SIJs demonstrate good diagnostic accuracy for active sacroiliitis compared with MRI.

Giant cell arteritis presenting as a stroke in the internal carotid artery territory: a case-based review.

Giant cell arteritis (GCA) is a large-vessel vasculitis, typically affecting the aorta and its branches. The involvement of vertebral and internal carotid arteries occurs in a limited number of cases, and stroke as a presenting symptom of GCA is extremely unusual: this subset of the disease has a poor prognosis and rarely responds to immunosuppression. We report the case of a 70-year-old woman, who presented to the Emergency Department for ischemic stroke, which appeared to be the first and only symptom of GCA. The prompt administration of steroids and tocilizumab (TCZ) led to clinical and radiological resolution, with no residual disability at 6-month follow-up. Our case-based review, highlighting the rarity of a large vessel vasculitis presenting only with a cerebrovascular accident, provides new evidence for the efficacy of TCZ even in more unusual varieties of GCA: in these cases, TCZ should be immediately prescribed, in order to prevent mortality and severe long-term morbidity.

Difference in pain and accuracy of two hyaluronic acid injection techniques for symptomatic knee osteoarthritis in overweight patients.

OBJECTIVES: To evaluate differences of injection related pain, and the accuracy of the techniques in two groups of overweight patients, performing the anterolateral approach for one group (G1) and the superolateral approach for the second group (G2). MATERIAL AND METHODS: In the study, 126 knee joints from 86 osteoarthritis (OA) patients were evaluated. Inclusion criteria were body mass index (BMI) ≥ 25, absence of effusion and coagulopathy. Pain evaluation during injection was evaluated with Visual Analogue Scale (VAS), while accuracy of the procedure was evaluated with ultrasound (US). RESULTS: The patients' mean age was 69.9 ±9.01, VAS for G1 group was 1.71 ±1.89, for G2 group was 1.74 ±1.31. Mean BMI was 29.69 ±2.86, for G1 group was 28.29 ±3.29, for G2 group was 30.32 ±2.41. No adverse events (AE) occurred in both studied groups. The accuracy rate of the procedure was 69.1% for G1 (38/55 knees), 95.7% for G2 (68/71 knees). No significant difference was found in VAS pain score between G1 and G2 group (p = 0.45). We found the significant correlation between BMI and VAS pain score in anterolateral accesses (G1) (r = 0.51; p < 0.005). No correlation was found between age and VAS pain score in anterolateral access (G1). For the superolateral access (G2), no correlation was found for age or BMI and VAS pain score. CONCLUSIONS: Hyaluronic acid injection is safe therapeutic option for knee OA with no significant differences between anterolateral and superolateral approaches in terms of pain in overweight patients. However, higher BMI seems to be a predictor of pain in anterolateral access, and the superolateral approach should be preferred in this group of patients.

Low muscle mass and body composition analysis in a group of postmenopausal women affected by primary Sjögren's syndrome.

OBJECTIVES: Sarcopenia is the pathological reduction of skeletal muscle mass and strength. This condition is often underestimated in clinical practice, particularly in connective tissue diseases. The purpose of this study is to evaluate the prevalence of low muscle mass in primary Sjögren's syndrome (pSS) and to explore the relationships linking muscles and bone tissue. MATERIAL AND METHODS: Twenty-eight postmenopausal pSS patients were matched with 30 healthy controls and their body composition analysis was performed by dual-energy X-ray absorptiometry to investigate for sarcopenia considering appendicular lean mass (ALM) and the skeletal muscle mass index (SMI) as references. Bone mineral density analysis of lumbar spine (L1-L4), whole femur, femoral neck and whole body was also performed. Linear regression was used to assess the relationship between body composition and bone mineralization. RESULTS: Low muscle mass was significantly higher in the pSS group compared to controls whether expressed as ALM, SMI [odds ratio (OR) = 18.40, confidence interval (CI): 4.84-72.08, p < 0.0001] or considering total body lean masses. Lean masses appeared to be the best estimators of bone mineralization: total lean body mass (TLBM) lumbar spine R 2 = 0.72, p < 0.0001; TLBM femoral neck R 2 = 0.36, p < 0.004; lean mass of upper limbs lumbar spine R 2 = 0.70, p < 0.0001; femoral neck R 2 = 0.66; lean mass of lower limbs lumbar spine R 2 = 0.66, p < 0.0001; femoral neck R 2 = 0.44, p = 0.008). Primary Sjögren's syndrome patients had a significantly higher android/gynoid fat ratio compared to controls. CONCLUSIONS: Female pSS patients have lower muscle mass compared to healthy controls and are exposed to a higher risk of developing sarcopenia than healthy subjects. Our research demonstrates that the amount of lean tissue is the main predictor of bone mineralization in pSS.

Bone-sparing effects of rituximab and body composition analysis in a cohort of postmenopausal women affected by rheumatoid arthritis - retrospective study.

OBJECTIVE: Osteoporosis is the most common bone tissue disease and it is characterized by a reduced bone mineral density (BMD). The main physiopathological mechanisms converge on the uncoupling between bone formation and resorption, thus leading to an enhanced risk of fractures. Several papers have documented the inverse relationships linking high inflammatory cytokines, anti-citrullinated protein antibodies, rheumatoid factor, and BMD in rheumatoid arthritis (RA). Rituximab (RTX) is a chimeric monoclonal antibody directed against the CD20 receptor of B cells. Since the Food and Drug Administration approved it for RA in 2006, there have been many clinical experiences regarding its use. Nevertheless, few studies evaluate the effect of rituximab on BMD. RA is a disease characterized by immune dysfunction with high levels of inflammatory cytokines, autoantibodies, and it is reasonable that a B cell depleting therapy could restore a physiological cytokine balance, thus exerting an osteoprotective effect on the bone tissue. The purpose of this paper is to highlight any difference in BMD and to assess differences in body composition over a retrospective 18-month follow-up period after RTX treatment with a B cell depleting therapy. MATERIAL AND METHODS: We analyzed by dual energy X-ray absorptiometry BMD expressed as g/cm2 and body composition modifications over 18 months with RTX treatment of 20 postmenopausal RA patients. RESULTS: After eighteen months of therapy with RTX, a statistically significant increase in vertebral (L1-L4) BMD and the stability of femoral BMD were documented. CONCLUSIONS: Rituximab is associated with an improvement of vertebral and preservation of femoral BMD, suggesting a bone-sparing effect due to B cell depletion. Furthermore, patients displayed a redistribution of fat masses toward the hip region.

A bispecific immunotweezer prevents soluble PrP oligomers and abolishes prion toxicity.

Antibodies to the prion protein, PrP, represent a promising therapeutic approach against prion diseases but the neurotoxicity of certain anti-PrP antibodies has caused concern. Here we describe scPOM-bi, a bispecific antibody designed to function as a molecular prion tweezer. scPOM-bi combines the complementarity-determining regions of the neurotoxic antibody POM1 and the neuroprotective POM2, which bind the globular domain (GD) and flexible tail (FT) respectively. We found that scPOM-bi confers protection to prion-infected organotypic cerebellar slices even when prion pathology is already conspicuous. Moreover, scPOM-bi prevents the formation of soluble oligomers that correlate with neurotoxic PrP species. Simultaneous targeting of both GD and FT was more effective than concomitant treatment with the individual molecules or targeting the tail alone, possibly by preventing the GD from entering a toxic-prone state. We conclude that simultaneous binding of the GD and flexible tail of PrP results in strong protection from prion neurotoxicity and may represent a promising strategy for anti-prion immunotherapy.

The Role of Multimodality Imaging in Monitoring Disease Activity and Therapeutic Response to Tocilizumab in Giant Cell Arteritis.

INTRODUCTION: Giant cell arteritis (GCA) is a large vessel (LV) vasculitis, mainly affecting elder patients. Monitoring GCA activity during tocilizumab (TCZ) treatment is an unmet need, since low serum levels of C-reactive protein (CRP) during treatment may underestimate disease activity. To date, few data are available on the role of different imaging techniques in monitoring GCA activity and response to treatment. We report herein a cohort of GCA patients treated with TCZ and followed up with multimodal imaging. Patients and Methods. We collected clinical, laboratory, and imaging data of 11 GCA patients treated with TCZ 162 mg subcutaneously every week. Disease activity was assessed at baseline and within 12 months from the start of treatment using different imaging techniques such as color Doppler ultrasonography (CDUS), magnetic resonance imaging/angiography (MRI/MRA), computed tomography angiography (CTA), and/or positron emission tomography (PET). RESULTS: Four patients were affected by cranial and 7 by LV-GCA. All patients were treated with oral glucocorticoids (GCs) (mean dose 55.68 mg ± 8.19 of prednisone or equivalent) in combination with TCZ. Treatment was preceded in 5 cases by 3 intravenous boluses of 1000 mg methylprednisolone. A significant decrease of the mean dose of oral GCs was observed between baseline and the last follow-up visit (4.65 ± 3.69 mg) (p = 0.003). TCZ treatment significantly decreased erythrocyte sedimentation rate (p < 0.01) and CRP levels (p < 0.01). At follow-up (mean 8.18 ± 3.63 months), all patients were in clinical and serological remission. Moreover, PET, CDUS, MRI/MRA, and CTA did not show any LVV finding. CONCLUSIONS: Our study highlights TCZ efficacy in inducing GCA remission and its steroid-sparing effect. We highlighted a reliability of imaging procedures in the evaluation of disease activity and treatment response. A close disease monitoring with imaging techniques should be taken into account in GCA patients during TCZ treatment.

Polymyalgia rheumatica following infective triggers or vaccinations: a different subset of disease?

OBJECTIVES: Polymyalgia rheumatica (PMR) is the commonest inflammatory disorder of the elderly; an association with environmental triggers and a deregulated immune response have been described. The aim of this study was to investigate the association of environmental triggers before the onset of PMR. MATERIAL AND METHODS: The database of 58 consecutive PMR patients recruited from a single rheumatology secondary care setting was retrospectively analyzed to investigate the frequency of environmental triggers and correlations with clinical characteristics, ultrasound and laboratory data. RESULTS: Fifteen PMR patients (26%) described a connection with environmental agents: six PMR patients reported a vaccination, 4 reported a respiratory tract infection, 5 reported seasonal influenza before the onset of the disease. The model of multivariate linear regression which better predicted a shorter time to normalize inflammatory reactants (R 2 = 27.46%, p = 0.0042) comprised the presence of an environmental trigger and a higher PCR. A linear regression analysis confirmed an inverse correlation between PCR at onset and time to normalize inflammatory reactant (r = -0.3031, p = 0.0208). A significant correlation was demonstrated between presence of environmental trigger and shorter time to normalize inflammation (r = -0.5215, p< 0.0001), and lesser frequency of gleno-humeral synovitis on US (r = -0.3774, p = 0.0038). CONCLUSIONS: Our work describes a correlation between environmental triggers in PMR and higher CRP at diagnosis, faster response to therapy, and milder shoulder synovitis. We may suppose that these patients belong to a more specific subtype of PMR, in whom external stimuli, such as vaccination or infection, may lead to a deregulated response within the context of an impaired senescent immuno-endocrine system.

Balance of Anti-CD123 Chimeric Antigen Receptor Binding Affinity and Density for the Targeting of Acute Myeloid Leukemia.

Chimeric antigen receptor (CAR)-redirected T lymphocytes are a promising immunotherapeutic approach and object of pre-clinical evaluation for the treatment of acute myeloid leukemia (AML). We developed a CAR against CD123, overexpressed on AML blasts and leukemic stem cells. However, potential recognition of low CD123-positive healthy tissues, through the on-target, off-tumor effect, limits safe clinical employment of CAR-redirected T cells. Therefore, we evaluated the effect of context-dependent variables capable of modulating CAR T cell functional profiles, such as CAR binding affinity, CAR expression, and target antigen density. Computational structural biology tools allowed for the design of rational mutations in the anti-CD123 CAR antigen binding domain that altered CAR expression and CAR binding affinity without affecting the overall CAR design. We defined both lytic and activation antigen thresholds, with early cytotoxic activity unaffected by either CAR expression or CAR affinity tuning but later effector functions impaired by low CAR expression. Moreover, the anti-CD123 CAR safety profile was confirmed by lowering CAR binding affinity, corroborating CD123 is a good therapeutic target antigen. Overall, full dissection of these variables offers suitable anti-CD123 CAR design optimization for the treatment of AML.