Differential Reactivity to IMPDH2 by Anti-rods/rings Autoantibodies and Unresponsiveness to Pegylated Interferon-alpha/Ribavirin Therapy in US and Italian HCV Patients

Purpose

Autoantibodies to cytoplasmic structures called rods and rings (RR) are primarily specific to patients with hepatitis C virus (HCV) infection treated with pegylated interferon-alpha/ribavirin (IFN/R). Our aim is to examine anti-RR antibodies specificity and correlation with the response to IFN/R therapy in two independent cohorts (US and Italy) of HCV patients.

Methods

Sera from the US cohort (n?=?47) and the Italian cohort (n?=?46) pre-selected for anti-RR antibodies were analyzed by immunofluorescence and radioimmunoprecipitation. The prevalence and titers of anti-RR were analyzed for correlation with the response to IFN/R therapy.

Results

In the US cohort, anti-RR antibodies were more frequently non-responders to IFN/R (71 % vs 29 % responders). Titers in responder patients (n?=?11) were ≤1:3200, whereas titers in non-responder patients (n?=?27) reached 1:819,200 (p?=?0.0016). In the Italian cohort, anti-RR titers ranged from 1:200 to >1:819,200 and only relapsers had the highest anti-RR titers. Radioimmunoprecipitation demonstrated that anti-RR autoantibodies were mainly anti-inosine monophosphate dehydrogenase 2 (IMPDH2) - 96 % in the Italian cohort vs. 53 % in the US cohort.

Conclusions

In the two cohorts analyzed, the anti-IMPDH2 response as a component of the anti-RR response is much more prominent in the Italian cohort. The reason for the difference between the US and Italian cohorts is unclear but it possibly illustrates the heterogeneity in response and the overall negative correlation between the production of these autoantibodies and response to IFN/R therapy. Patients with high titer anti-RR antibodies are either relapsers (Italian) or non-responders/relapsers (US).     

Assessment of humoral and cellular immunity induced by the BNT162b2 SARS-CoV-2 vaccine in healthcare workers,elderly people,and immunosuppressed patients with autoimmune disease

The development of vaccines to prevent SARS-CoV-2 infection has mainly relied on the induction of neutralizing antibodies (nAbs) to the Spike protein of SARS-CoV-2, but there is growing evidence that T cell immune response can contribute to protection as well. In this study, an anti-receptor binding domain (RBD) antibody assay and an INFγ-release assay (IGRA) were used to detect humoral and cellular responses to the Pfizer-BioNTech BNT162b2 vaccine in three separate cohorts of COVID-19-naïve patients: 108 healthcare workers (HCWs), 15 elderly people, and 5 autoimmune patients treated with immunosuppressive agents. After the second dose of vaccine, the mean values of anti-RBD antibodies (Abs) and INFγ were 123.33 U/mL (range 27.55–464) and 1513 mIU/mL (range 145–2500) in HCWs and 210.7 U/mL (range 3–500) and 1167 mIU/mL (range 83–2500) in elderly people. No correlations between age and immune status were observed. On the contrary, a weak but significant positive correlation was found between INFγ and anti-RBD Abs values (rho = 0.354, p = 0.003). As to the autoimmune cohort, anti-RBD Abs were not detected in the two patients with absent peripheral CD19⁺B cells, despite high INFγ levels being observed in all 5 patients after vaccination. Even though the clinical relevance of T cell response has not yet been established as a correlate of vaccine-induced protection, IGRA testing has showed optimal sensitivity and specificity to define vaccine responders, even in patients lacking a cognate antibody response to the vaccine.

     

Cloning and characterization of DNA polymerase η from Trypanosoma cruzi: Roles for translesion bypass of oxidative damage

We report the cloning and characterization of the DNA polymerase η gene from Trypanosoma cruzi (TcPolη), the causative agent of Chagas disease. This protein, which can bypass cyclobutane pyrimidine dimers, contains motifs that are conserved between Y family polymerases. In vitro assays showed that the recombinant protein is capable of synthesizing DNA in undamaged primer‐templates. Intriguingly, T. cruzi overexpressing TcPolη does not increase its resistance to UV‐light (with or without caffeine) or cisplatin, despite the ability of the protein to enhance UV resistance in a RAD30 mutant of Saccharomyces cerevisiae. Parasites overexpressing TcPolη are also unable to restore growth after treatment with zeocin or gamma irradiation. T. cruzi overexpressing TcPolη are more resistant to treatment with hydrogen peroxide (H₂O₂) compared to nontransfected cells. The observed H₂O₂ resistance could be associated with its ability to bypass 8‐oxoguanine lesions in vitro. The results presented here suggest that TcPolη is able to bypass UV and oxidative lesions. However the overexpression of the gene only interferes in response to oxidative lesions, possibly due to the presence of these lesions during the S phase. Environ. Mol. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.     

A PET study of the pathophysiology of negative symptoms in schizophrenia. Positron emission tomography

OBJECTIVE: Positron emission tomography (PET) was used to compare cerebral metabolic patterns in schizophrenic subjects with predominantly negative symptoms (alogia, affective flattening, avolition, and attentional impairment) and in those with predominantly positive symptoms. METHOD: Fourteen right-handed male subjects with DSM-IV schizophrenia were assigned to groups with predominantly negative or predominantly positive symptoms on the basis of their post-drug-washout scores on the Positive and Negative Syndrome Scale. The patients were compared to seven age- and gender-matched normal volunteers. PET scans with [(18)F]fluorodeoxyglucose were obtained during a degraded Continuous Performance Task to measure absolute glucose metabolic rates. Statistical parametric mapping was used to estimate the regional metabolic differences between groups. RESULTS: The subjects with predominantly negative symptoms had significant differences in glucose metabolic rates, compared to both the subjects with predominantly positive symptoms and the normal subjects. Negative symptom subjects had a lower glucose metabolic rate in the right hemisphere, especially in the temporal and ventral prefrontal cortices, compared to the other groups, and higher metabolic rates in the cerebellar cortex and in the lower deep cerebellar nuclei. Negative symptom subscale scores were negatively correlated with glucose metabolic rates for most of the brain areas that differentiated subjects with predominantly negative symptoms from those with predominantly positive symptoms. CONCLUSIONS: Schizophrenic subjects with predominantly negative symptoms have greater metabolic abnormalities than subjects with predominantly positive symptoms, particularly in frontal, temporal, and cerebellar circuitry. These results are consistent with abnormalities in corticocortical, corticobasal ganglia, mesocortical dopamine, and cerebellar-thalamic-prefrontal circuits, which may underlie the negative symptoms of schizophrenia.     

Brain metabolic effects of Neotrofin in patients with Alzheimer's disease

Lead (Pb) is a common neurotoxicant of major public health concern. Previous studies revealed that cultured oligodendrocyte progenitor cells (OPCs) are highly vulnerable to Pb toxicity. The present study examines the effect of Pb on the survival, proliferation and differentiation of OPCs in vitro. Dose-response studies showed that> or = l5-10 microM Pb is cytotoxic to OPCs within 24 h. However, 1 microM of Pb was found to inhibit the proliferation and differentiation of OPCs without affecting cell viability. Pb markedly decreased the proliferative capability of OPCs and inhibited cell-intrinsic lineage progression of OPCs at a late progenitor stage. The Pb-induced decrease of proliferation and differentiation was abolished by inhibition of protein kinase C (PKC) with bisindolylmaleimide I, while the effect of the PKC-activating agent phorbol-12,13-didecanoate was potentiated by Pb. Furthermore, Pb exposure of OPCs caused the translocation of PKC from the cytoplasm to membrane without an increase in total cellular PKC enzymic activity. These results indicate that Pb inhibits the proliferation and differentiation of oligodendrocyte lineage cells in vitro through a mechanism requiring PKC activation.     

Myocardial metabolic and receptor imaging in idiopathic dilated cardiomyopathy

Idiopathic dilated cardiomyopathy (IDC) is a distinct disease of the myocardium, of unknown etiology. The disease can occur acutely, or evolve in a subacute fashion. IDC is often associated with a substantial impairment of ventricular function, which may recover over time. Although spontaneous recovery of LV function occurs in 20%-45% of newly diagnosed patients, the majority of patients do not do well. IDC has an average 5-year mortality of 20%. Abnormalities of energetics, perfusion, and adrenergic control of the myocardium are markers of the status of LV dysfunction. As the heart fails, changes occur in the production and catabolism of high-energy substrates, the efficiency of mitochondrial oxidative processes, the distribution of resting perfusion and coronary vasodilating capacity and the adrenergic receptor density and function. This article reviews the information provided by metabolic and receptor imaging in patients with IDC, and the role the data may play in patient management.     

Risk factors for dental caries in children with cerebral palsy

This study was conducted to examine the oral condition and the salivary and microbiological parameters associated with dental caries in 62 children with cerebral palsy, who came from households of low socioeconomic status (Study Group). This group had mixed (6 to 11 years old) and permanent (11 to 16 years old) dentition. Dental examinations were performed to measure dental caries, plaque index, salivary levels of mutans streptococci and lactobacilli, salivary flow rate, pH of stimulated saliva, and buffer capacity of saliva. A group of 67 non-handicapped children from similar socioeconomic backgrounds also were examined using these parameters (Control Group). Data were analyzed statistically by non-parametric tests and by correlation. The results showed that children with cerebral palsy who had permanent dentitions had a higher mean decayed, missing and filled surfaces index, as well as a higher plaque index for both sexes. Microbiological examination revealed higher levels of mutans streptococci among Study Group subjects with mixed dentition than in the Control Group. Also, lactobacillus counts were higher in the Study Group, regardless of sex or dentition. With respect to salivary flow rate, pH and buffering capacity, lower mean values were obtained for the Study Group.     

Effects of adrenergic amines on electrophysiological properties and automaticity of neonatal and adult canine Purkinje fibers: evidence for alpha- and beta-adrenergic actions.

We determined age-related differences in automaticity and responsiveness of cardiac Purkinje fibers from adult and neonatal dogs to graded concentrations of epinephrine, isoproterenol, and phenylephrine. Purkinje fibers were studied with standard microelectrode techniques during superfusion with Tyrode's solution at 37 degrees C. Control spontaneous rates for adults and neonates did not differ significantly. There was a biphasic response to all agonists such that rate decreased at low and increased at high concentrations. The decrease was greater with phenylephrine and epinephrine than with isoproterenol. The increase in rate was greater with isoproterenol and epinephrine than with phenylephrine. Propranolol shifted the dose-response curves downward and to the right for all agonists; phentolamine, shifter the curves upward and to the left. Epinephrine and isoproterenol dose-response curves for the neonates were upward and to the left of those for adults. Phenylephrine curves were identical for adults and neonates. Thus there are alpha- and beta-adrenergic effects on Purkinje fiber automaticity; the former decrease and the latter increase rate. Furthermore, the effects on automiticity of beta-adrenergic amines are greater in the neonates than in the adult.     

Renal insulin resistance syndrome, adiponectin and cardiovascular events in patients with kidney disease: the mild and moderate kidney disease study

The relationship among insulin resistance, adiponectin, and cardiovascular (CV) morbidity in patients with mild and moderate kidney disease was investigated. Insulin sensitivity (Homeostasis Model Assessment of Insulin Resistance [HOMA-IR]) and adiponectin plasma levels were assessed in 227 nondiabetic renal patients at different degrees of renal dysfunction and in 76 healthy subjects of similar age and gender distribution and body mass index. In renal patients, association with prevalent CV events was evaluated, and incident CV events were evaluated in a prospective study. HOMA-IR was markedly higher in patients than in healthy subjects (3.59 +/- 3.55 versus 1.39 +/- 0.51; P < 0.01). In renal patients, HOMA-IR was significantly correlated with body mass index (r = 0.477; P < 0.01), triglycerides (r = 0.384; P < 0.01), adiponectin plasma levels (r = -0.253; P < 0.01), and age (r = 0.164; P < 0.05), but not with renal function (GFR by iod-thalamate clearance). Patients with previous CV events were significantly older, had higher HOMA-IR and serum triglycerides, and had lower adiponectin plasma levels (all P < 0.05). Logistic regression analysis revealed age (P < 0.001) and adiponectin (P < 0.002) as independent variables related to prevalent CV events. In the prospective study, median follow-up was 54 mo. Patients who experienced CV events had significantly higher serum glucose and lower adiponectin plasma levels (both P < 0.05). In patients with chronic kidney diseases, a syndrome of insulin resistance is present even in the earliest stage of renal dysfunction, and several components of this syndrome are associated with CV events. Moreover, hypoadiponectinemia is a novel putative CV risk factor in patients with mild and moderate renal failure.     

Chronic angiotensin II receptor blockade reduces (intra)renal vascular resistance in patients with type 2 diabetes

Increased (intra)renal activity of the renin-angiotensin system may cause a persistent increase in renovascular resistance and intraglomerular pressure in patients with diabetes, thus contributing to the development of diabetic renal damage. The effect of chronic angiotensin II subtype 1 receptor blockade on (intra)renal hemodynamics in patients with type 2 diabetes was examined in a double-blind parallel group study. Patients were treated with 40 mg of olmesartan (n = 19) or placebo (n = 16), and renal hemodynamics were assessed before and after 12 wk of treatment using inulin and para-aminohippurate clearance techniques. Olmesartan significantly reduced 24-h ambulatory systolic and diastolic BP (both P < 0.05). In parallel, effective renal plasma flow increased significantly from 602 +/- 76 to 628 +/- 87 ml/min per 1.73 m(2), whereas filtration fraction and renovascular resistance decreased significantly (all P < 0.05). With placebo treatment, effective renal plasma flow decreased and filtration fraction increased significantly (both P < 0.05). GFR was not affected by both treatments. Active plasma renin concentration increased considerably (P < 0.05) with olmesartan therapy but remained unchanged with placebo treatment. Nitric oxide metabolism (plasma nitrate and nitrite) and asymmetric dimethylarginine blood levels were not affected by olmesartan and placebo therapy. In contrast, plasma 8-isoprostane 15(S)-8-iso-prostaglandin F(2a) concentration, a biochemical marker of oxidative stress, decreased significantly (P < 0.05) with olmesartan treatment. Chronic angiotensin II subtype 1 receptor blockade decreases (intra)renal vascular resistance and increases renal perfusion despite significant BP reduction. In addition, it significantly reduces oxidative stress. These effects of angiotensin II receptor antagonists may contribute to their beneficial long-term renal effects in patients with type 2 diabetes.