Sporadic hereditary neuropathies misdiagnosed as chronic inflammatory demyelinating polyradiculoneuropathy: Pitfalls and red flags

Hereditary neuropathies may be misdiagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). A correct diagnosis is crucial for avoiding unnecessary therapies and access genetic counseling. We report on nine patients (seven men, mean age 49.2 ± 16.1) diagnosed with and treated as CIDP, in whom mutations or variants of unknown significance (VUS) in genes associated with hereditary neuropathies were reported. All underwent neurological and neurophysiological examination, eight also cerebrospinal fluid (CSF) analysis. In 4/9, nerve ultrasound and/or MR‐neurography were performed. All the patients complained of progressive upper or lower limbs sensory‐motor symptoms, with heterogeneous disease duration (1‐34 years, mean 8.6 ± 10.8). Neurophysiology showed demyelinating signs in seven patients, mixed findings with predominant axonal damage in two patients. Neuroimaging disclosed diffuse abnormalities at proximal and distal segments. Molecular screening showed PMP22 duplication in two patients, mutations in the MPZ, EGR2, and GJB1 genes were reported in each of the remaining patients. The two patients with mixed neurophysiological findings had p.Val30Met mutation in the transthyretin gene. Two patients had VUS in the MARS and HSPB1 genes. Four patients had partial response to immunomodulant therapies, and CSF and neurophysiological features suggesting an inflammatory condition concomitant with the hereditary neuropathy. Hereditary neuropathy may be misdiagnosed with CIDP. The most common pitfalls are CSF (high protein levels and oligoclonal bands), incorrect interpretation of neurophysiology, and transient benefit from therapies. Neuroimaging may be helpful in cases with atypical presentations or when severe axonal damage complicate the neurophysiological interpretation.     

Psychosocial adjustment of post-poliomyelitis ventilator assisted individuals.

The effect of severe disability, tracheostomy, and ventilator use on psychosocial functioning, gainful employment, life satisfaction, and perceived well-being were studied for a population of 395 ventilator assisted post-poliomyelitis individuals (PVAIs). Standard psychosocial survey instruments and other general questioning were used. Two-hundred-seventy-three physically intact health care professionals served as controls. They were surveyed about their own life satisfaction and perceived well-being and were asked to judge how severely disabled ventilator assisted individuals would respond to such questioning. The relative distress associated with ventilator use was also evaluated in a similar manner. Fifty six of 380 responding PVAIs (14.7%) expressed dissatisfaction with their lives in general. This compares with 8.5% of the controls and 7% of a previously studied general population. The controls significantly underestimated the patients' life satisfaction and well-being scores and significantly overestimated the relative hardship associated with ventilator use. The post-polio individuals using noninvasive methods of assisted ventilation were also significantly more satisfied with their lives than were those ventilated via tracheostomy. Fifty-seven of 148 (39%) individuals married and 165 of 395 (42%) individuals were gainfully employed during long-term ventilator use. We conclude that many severely disabled post-poliomyelitis ventilator users lead productive lives. The vast majority have a positive affect and are satisfied with life. Noninvasive ventilatory support alternatives may lend to greater life satisfaction for these individuals than ventilation delivered via an indwelling tracheostomy. Health care professionals may significantly underestimate their patients' satisfaction with life and this may have a bearing on patient management.     

Probabilistic approach for the risk assessment of nanomaterials: A case study for graphene nanoplatelets

An experimental probabilistic approach for health risk assessment was applied for graphene nanoplatelets (GNPs). The hazard assessment indicated a low level of toxicity for the GNPs. The benchmark dose method, based on sub-chronic and chronic inhalation exposure studies, was used to quantify a guidance value (BMC_h) for occupational inhalation exposure to GNPs, expressed as a lognormal distribution with a geometric mean?±?geometric standard deviation of 0.212?±?7.79?mg/m³ and 9.37?×?10⁴?±?7.6 particle/cm³. Exposure scenarios (ES) were defined based on the scientific literature for large-scale production (ES1) and manufacturing (ES2) of GNPs; a third ES, concerning in-lab handling of GNPs (ES3) was based on results of experiments performed for this study. A probability distribution function was then assumed for each ES. The risk magnitude was calculated using a risk characterization ratio (RCR), defined as the ratio of the exposure distributions and the BMC_h distribution. All three ES resulted in RCR distributions ≥1 (i.e. risk present); however, none of the ES had a statistically significant level of risk at a 95% confidence interval. A sensitivity analysis indicated that ～75% of the variation in the RCR distributions was due to uncertainties in the BMC_h calculation.     

Large-scale survey of naturally occurring HBV polymerase mutations associated with anti-HBV drug resistance in untreated patients with chronic hepatitis B

Summary. Drug resistance is a major limitation for the long‐term efficacy of antiviral therapy with nucleos(t)ide analogues (NAs) in chronic hepatitis B (CHB). Antiviral resistance mutations may pre‐exist in the overall viral population of untreated patients. We aimed to assess the prevalence of such hepatitis B virus (HBV) variants in a large cohort of NAs‐naïve patients with CHB and to explore possible association with viral and host variables. Serum samples from 286 NAs‐naïve consecutive patients with CHB were tested for serum HBV‐DNA, and 255 of them having HBV‐DNA > 1000 IU/mL were further analysed for drug resistance mutations by INNO‐LiPA HBV DRv2/v3. NAs‐naïve patients analysed were mainly men (73%), Caucasians (85%), hepatitis B e Antigen (HBeAg) negative (79%) and genotype D (69%), with a mean age of 43.2 ± 13.4 years. HBV mutations associated with antiviral drug resistance were detected in 13 (5%) patients: three patients infected with HBV genotype C had the rtM204V + rtL180M mutations associated with lamivudine (LMV) resistance. Four patients had the rtI233V mutation that may reduce sensitivity to adefovir, and three patients had the rtM250L/V mutation typical of entecavir resistance. LMV compensatory mutations rtL80V and rtV173L were seen in two and one patients, respectively. No relationship was seen between presence of resistant or compensatory mutations and HBV‐DNA levels, HBeAg/anti‐HBe status or previous IFN therapy. These results confirm that HBV mutations, which confer resistance against currently available anti‐HBV NAs, may already exist in patients who have never received the drug.     

Role of kinin B2 receptor signaling in the recruitment of circulating progenitor cells with neovascularization potential

Reduced migratory function of circulating angiogenic progenitor cells (CPCs) has been associated with impaired neovascularization in patients with cardiovascular disease (CVD). Previous findings underline the role of the kallikrein-kinin system in angiogenesis. We now demonstrate the involvement of the kinin B2 receptor (B(2)R) in the recruitment of CPCs to sites of ischemia and in their proangiogenic action. In healthy subjects, B(2)R was abundantly present on CD133(+) and CD34(+) CPCs as well as cultured endothelial progenitor cells (EPCs) derived from blood mononuclear cells (MNCs), whereas kinin B1 receptor expression was barely detectable. In transwell migration assays, bradykinin (BK) exerts a potent chemoattractant activity on CD133(+) and CD34(+) CPCs and EPCs via a B(2)R/phosphoinositide 3-kinase/eNOS-mediated mechanism. Migration toward BK was able to attract an MNC subpopulation enriched in CPCs with in vitro proangiogenic activity, as assessed by Matrigel assay. CPCs from cardiovascular disease patients showed low B(2)R levels and decreased migratory capacity toward BK. When injected systemically into wild-type mice with unilateral limb ischemia, bone marrow MNCs from syngenic B(2)R-deficient mice resulted in reduced homing of sca-1(+) and cKit(+)flk1(+) progenitors to ischemic muscles, impaired reparative neovascularization, and delayed perfusion recovery as compared with wild-type MNCs. Similarly, blockade of the B(2)R by systemic administration of icatibant prevented the beneficial effect of bone marrow MNC transplantation. BK-induced migration represents a novel mechanism mediating homing of circulating angiogenic progenitors. Reduction of BK sensitivity in progenitor cells from cardiovascular disease patients might contribute to impaired neovascularization after ischemic complications.     

Genetic determinants of chronic oxaliplatin‐induced peripheral neurotoxicity: a genome‐wide study replication and meta‐analysis

We aimed at validating the role of genetic variants identified by a recent genome‐wide association study (GWAS) as determinants of chronic oxaliplatin‐induced peripheral neurotoxicity (OXAIPN). Eight polymorphisms (rs10486003, rs2338, rs843748, rs797519, rs4936453, rs12023000, rs17140129, and rs6924717) were genotyped in a total of 150 colorectal cancer patients of Caucasian origin receiving oxaliplatin‐based chemotherapy. The severity grade of chronic OXAIPN was assessed by NCI‐CTC criteria and the clinical version of the Total Neuropathy Score^© (TNSc^©). None of the polymorphisms investigated was found associated with grade ≥ 2 chronic OXAIPN (NCI‐CTC criteria), while a nominal association emerged for ACYP2 rs843748 when using the TNSc^© scale (dominant model: odds ratio [OR]: 0.27, 95% confidence interval [CI]: 0.10–0.75, P = 0.008). In the combined analysis of this results with data of the two previously published studies which assessed chronic OXAIPN by NCI‐CTC criteria, evidence suggestive of association with chronic OXAIPN (NCI‐CTC criteria) was found for ACYP2 rs843748 (dominant model: OR: 2.40, 95%CI: 1.40–5.24, P = 0.027), which, however, did not remain significant after correction for multiple testing (threshold P‐value <0.00625). These findings suggest a minor role of the single nucleotide polymorphisms (SNPs) investigated as genetic determinants of chronic OXAIPN. These results also highlight the importance of replication studies with meta‐analysis for validation of GWAS findings.