Variant Type X91+ Chronic Granulomatous Disease: Clinical and Molecular Characterization in a Chinese Cohort

Purpose: We aimed to report the clinical and immunological characteristics of variant type X91+ CGD in a Chinese cohort.Methods: The clinical manifestations and immunological phenotypes of X91+ CGD patients were collected. Dihydrorhodamine (DHR) analysis was performed to evaluate neutrophil function. Gp91phox protein expression was determined by flow cytometry-based extracellular staining with the monoclonal antibody (mAb) 7D5. Results: X91+CGD patients accounted for 8% (7/85) of all patients with GCD. The median onset age in the 7 X91+ CGD patients was 4 months. Six patients received the same BCG vaccine strain, and three had probable BCG infections. Moreover, 4 patients were highly suspected of having Mycobacterium tuberculosis infection. Recurrent infections of the lungs and soft tissues (3/7) were the most common symptoms. Two patients had noninfectious recurrent oral ulcers and received interferon gamma (IFN-γ) treatment afterward. In our cohort, the stimulation index (SI) of the 7 X91+ CGD patients ranged widely from 1.9 to 67.5, while the SI ranged from 1.2 to 35.7 in patents with X910 CGD. The level of SI between these two groups was statistically significant (P<0.05). CYBB mutations associated with X91+CGD were usually located in or near the FAD and NADPH binding domains. Three new X91+ CGD related mutations (c.1462-2 A>T, c.1243C>T and c.925G>A) were identified. Conclusions: Variant type X91+ CGD may have varied severities of clinical manifestations. Moreover, the laboratory findings of X91+ CGD could present with a moderate neutrophil stimulation index. We should deepen our understanding of the X91+ variant CGD to prevent missed diagnosis.

BNT162b2 Vaccination efficacy is marginally affected by the SARS-CoV-2 B.1.351 variant in fully vaccinated individuals.

Background Israeli has vaccinated over 80% of its adult population, with two doses of the Pfizer BNT162b2 vaccine. This intervention has been highly successful in curtailing the coronavirus 2 outbreak. One major concern is the ability of the virus to mutate which potentially can cause SARS-CoV-2 to partially escape from the immune system. Here we evaluate the efficacy of the Pfizer vaccine against the B.1.351 variant. Methods The Ministry of Health, initiated sequencing of selected positive swab samples identified as being of interest. We used logistic regression, with variant type as the dependent variable, vaccination status as the main explanatory variable, controlling for age, sex, subpopulation, place of residence and time of sample, to estimate the odds ratio for a vaccinated case to have the B. 1.351 versus the B.1.1.7 variant, within vaccinated and unvaccinated persons who tested positive. Findings There were 19 cases of B.1.351 variant (3.2%) among those vaccinated more than 14 days before the positive sample and 88 (3.5%) among the unvaccinated. The estimated odds ratio was 1.29 [95% CI: 0.66-2.50]. From this result, assuming the efficacy against the B.1.1.7 variant to be 95%, the estimated efficacy against the B.1.351 variant was 94% [95% CI: 87-97%]. Interpretation Despite the concerns caused by the B.1.351 variant, the BNT162b2 vaccine seems to provide substantial immunity against both that variant and the B.1.1.7. Our results suggest that from 14 days following the second vaccine dose the efficacy of BNT162b2 vaccine is at most marginally affected by the B.1.351 variant. Funding No funding

Protein Truncating Variants of colA in Clostridium perfringens Type G Strains

Extracellular matrix (ECM) degrading enzymes produced by Clostridium perfringens may play an important role during the initial phases of avian necrotic enteritis by facilitating toxin entry in the intestinal mucosa and destruction of the tissue. C. perfringens is known to produce several ECM-degrading proteases, such as kappa toxin, an extracellular collagenase that is encoded by the colA gene. In this study, the colA gene sequence of a collection of 48 C. perfringens strains, including pathogenic (i.e. toxinotype G) and commensal (i.e. toxinotype A) chicken derived strains and strains originating from other host species, was analyzed. Although the colA gene showed a high level of conservation (&gt;96% nucleotide sequence identity), several gene variants carrying different nonsense mutations in the colA gene were identified, leading to the definition of four truncated collagenase variant types (I-IV). Collagenase variant types I, III and IV have a (nearly) complete collagenase unit but lack parts of the C-terminal recruitment domains, whereas collagenase variant types II misses the N-terminal part of collagenase unit. Gene fragments encoding a truncated collagenase were mainly linked with necrotic enteritis associated C. perfringens type G strains with collagenase variant types I and II being the most prevalent types. Gelatin zymography revealed that both recombinant full-length and variant type I collagenase have active auto-cleavage products. Moreover, both recombinant fragments were capable of degrading type I as well as type IV collagen, although variant type I collagenase showed a higher relative activity against collagen type IV as compared to full-length collagenase. Consequently, these smaller truncated collagenases might be able to break down collagen type IV in the epithelial basement membrane of the intestinal villi and so contribute to the initiation of the pathological process leading to necrotic enteritis.

FOLFIRINOX in advanced pancreatic cancer patients with the double-variant type of UGT1A1 *28 and *6 polymorphism: a multicenter, retrospective study

Background UGT1A1 *28 and *6 polymorphism is associated with reduced enzyme activity and severe toxicities of irinotecan, especially in patients with homozygous or heterozygous for UGT1A1*28 or *6 polymorphism for both UGT1A1*28 and *6 (double-variant-type of UGT1A1 polymorphism, UGT1A1-DV). FOLFIRINOX is one of the standard treatments for metastatic pancreatic cancer (PC). The optimal dose of irinotecan as a component of the FOLFIRINOX has not been established yet for patients with UGT1A1-DV. Patients and methods Advanced PC patients with UGT1A1-DV who had received at least one cycle of FOLFIRINOX from December 2013 to March 2016 were collected retrospectively conducted at multicenter in Japan. We evaluated the patient characteristics, efficacy and safety of FOLFIRINOX and investigate the optimal initial dose of irinotecan in Japanese advanced PC patients with UGT1A1-DV. Results A total of 31 patients were enrolled. Grade 4 neutropenia was seen more frequently (67%; 4/6) in patients who had received irinotecan at an initial dose of ≥ 150 mg/m2 than in those who had received the drug at an initial dose of ≤ 120 mg/m2 (20%; 5/24). The response rate (RR) and progression-free survival (PFS) in patients given irinotecan of ≤ 120 mg/m2 were 21.4% and 8.1 months, respectively, which were consistent with previous report for patients without UGT1A1-DV. Conclusion Based on our findings, we recommend that in Japanese advanced PC patients with UGT1A1- DV treated with FOLFIRINOX, irinotecan be administered at an initial dose of ≤ 120 mg/m2.