First Description of Late-Onset Autoinflammatory Disease Due to Somatic NLRC4 Mosaicism.

OBJECTIVE: Autoinflammatory diseases are inherited disorders of innate immunity that usually start during childhood. However, several recent reports have described an increasing number of patients with autoinflammatory disease starting in adulthood. This study was undertaken to investigate the underlying cause of a case of late-onset uncharacterized autoinflammatory disease. METHODS: Genetics studies were performed using Sanger sequencing and next-generation sequencing (NGS) methods. In silico, in vitro, and ex vivo analyses were performed to determine the functional consequences of the detected variant. RESULTS: We studied a 57-year-old woman who at the age of 47 years began to have recurrent episodes of fever, myalgias, arthralgias, diffuse abdominal pain, diarrhea, adenopathies, and systemic inflammation, which were relatively well controlled with anti-interleukin-1 (anti-IL-1) drugs. NGS analyses did not detect germline variants in any of the known autoinflammatory disease-associated genes, but they identified the p.Ser171Phe NLRC4 variant in unfractionated blood, with an allele fraction (2-4%) compatible with gene mosaicism. Structural modeling analyses suggested that this missense variant might favor the open, active conformation of the NLRC4 protein, and in vitro and ex vivo analyses confirmed its propensity to oligomerize and activate the NLRC4 inflammasome, with subsequent overproduction of IL-18. CONCLUSION: Our findings indicate that the postzygotic p.Ser171Phe NLRC4 variant is a plausible cause of the disease in the enrolled patient. Functional and structural studies clearly support, for the first time, its gain-of-function behavior, consistent with previously reported NLRC4 pathogenic variants. These novel findings should be considered in the diagnostic evaluation of patients with adult-onset uncharacterized autoinflammatory disease.

Short-, Intermediate-, and Long-Term Changes in Basophil Reactivity Induced by Venom Immunotherapy.

PURPOSE: The basophil activation test (BAT) has been used to monitor venom immunotherapy (VIT) due to its high specificity. A previous study has reported a good correlation between a significant decrease in basophil activation during 5 years of VIT and clinical protection assessed by sting challenge. The following prospective study was performed to examine changes in basophil reactivity over a complete VIT period of 5 years. METHODS: BAT in a dose-response curve was studied prospectively in 10 hymenoptera venom-allergic patients over 5 years of VIT. BAT was performed at the time of diagnosis, 1 month after finishing the VIT build-up phase, and 3, 6, 12, 24, and 60 months after beginning treatment. The repeated measures ANOVA was applied to evaluate basophil activation changes throughout VIT. A cross-sectional study was also performed in 6 patients who received treatment for more than 3 years, and in another 12 patients who followed immunotherapy for at least 5 years. RESULTS: An early activation decrease was observed during the first 3 months of treatment, compared to pre-treatment values. This activation decrease was not maintained 6 to 18 months after treatment, but was observed again after 2 years of treatment, and maintained until the completion of the 5-year immunotherapy period. In cross-sectional analysis, the 6 patients who received treatment for 3 years, and 9 of the 12 patients who received treatment for 5 years, had negative BAT results. Three patients in this last group had positive BAT results and 2 patients had systemic reactions after field stings. CONCLUSIONS: BAT appears to be an optimal non-invasive test for close monitoring of VIT.

Association of vascular factors and amnestic mild cognitive impairment: a comprehensive approach.

BACKGROUND AND OBJECTIVE: Current evidence shows that numerous classic vascular risk factors (VRF) contribute to mild cognitive impairment (MCI), but the effects of emerging VRFs are less well-known. Using a comprehensive approach, we assessed the frequency and strength of association between MCI and classic VRFs, subclinical markers of atherosclerosis (cystatin C, lipoprotein(a), high-sensitivity C-reactive protein, and intima-media thickness) and white matter hyperintensities (WMH). METHODS: In this case-control study of consecutive MCI patients and cognitively normal controls, subjects underwent clinical and neuropsychological examinations, laboratory analyses, a carotid duplex scan, and a brain magnetic resonance imaging scan. RESULTS: The study included 105 patients with amnestic MCI (aMCI): 24 with single domain amnestic MCI, 81 with multiple domain amnestic MCI, and 76 controls. Compared to controls, patients with aMCI were significantly older and had higher rates of arterial hypertension, atrial fibrillation, and depression. They also had a larger intima-media thickness and higher load of WMHs, both periventricular (WMHpv) and subcortical (WMHsc). In the adjusted analysis, all variables except WMHsc displayed a significant association with aMCI. Body mass index exerted a protective effect. CONCLUSIONS: Our findings suggest a direct association between aMCI and age, hypertension, atrial fibrillation depression, intima-media thickness, and WMHpv. Body mass index has a protective effect on this MCI subtype.

Genetic immunization: a new monoclonal antibody for the detection of BCL-6 protein in paraffin sections.

Genetic immunization can be combined with hybridoma technology to generate high-affinity monoclonal antibodies (MAbs). A new anti-BCL-6 MAb (GI191E/A8) was produced by cloning full-length BCL-6 cDNA into a eukaryotic vector and delivering this into mouse epidermis using a helium gene gun. A comparative study was made of the specificity and the effects of formalin fixation on immunohistochemistry quality of GI191E/A8 and two other anti-BCL-6 MAbs. To evaluate its possible application to differential diagnosis of lymphomas, two tissue microarrays (89 diffuse large B-cell lymphomas and 24 B-cell chronic lymphocytic leukemia cases) were stained with GI191E/A8 and another anti-BCL-6 MAb produced by conventional means. Using GI191E/A8, the detection of BCL-6 protein was significantly increased, and its specificity was independent of formalin-fixation time. Using automatic quantified analysis, the correlation between the two anti-BCL-6 MAbs tested was identical in cases with overexpression or absence of BCL-6. In cases with intermediate BCL-6 protein expression, detection with GI191E/A8 was more sensitive. A significant association of higher BCL-6 expression and longer median overall survival times in diffuse large B-cell lymphomas was found. Using conventionally produced MAbs in the same patient group, the association was not significant.