PFAPA flares observed during COVID outbreak: can emotional stress trigger PFAPA attacks? A multicenter cohort study.

OBJECTIVE: It is common knowledge among clinicians who treat PFAPA (Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis) patients that emotional stress can trigger PFAPA attacks similarly to other autoinflammatory diseases. However, it has never been proved scientifically. Our aim was to examine whether emotional stress serves as a trigger for PFAPA attacks. METHODS: Patients aged 3-12 years, with active PFAPA, from two Israeli medical centers were enrolled to this study. Patient's parents were reached via phone calls in two occasions: a stressful period related to the COVID-19 pandemic restrictions and a less stressful period. In both times they were asked to report occurrence of PFAPA attacks in the preceding 2 weeks. The relative stress levels of the two periods were validated by an emotional distress scale questionnaire. The significance level was set at 0.05. RESULTS: Mean age was 7.28 ± 2.7 for the 99 paediatric patients enrolled in the study. Scores for the mean emotional distress questionnaire were statistically significant higher in the stressful period compared to the less stressful period (35.6 ± 8.1 vs. 32.1 ±7.7, respectively, P = 0.047). In the stressful period, 41 (38.7%) reported at least one attack during the preceding 2 weeks, compared to 24 (22.6%) in the less stressful period (p = 0.017). CONCLUSION: PFAPA flares during COVID-19 outbreak are described. This study is the first to suggest that emotional stress is associated with PFAPA attacks.

Familial Periodic Fever, Aphthous Stomatitis, Pharyngitis and Adenitis Syndrome; Is It a Separate Disease?

Introduction: Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA) is the most common periodic fever syndrome in the pediatric population, yet its pathogenesis is unknown. PFAPA was believed to be sporadic but family clustering has been widely observed. Objective: To identify demographic and clinical differences between patients with PFAPA and a positive family history (FH+) as compared to those with no family history (FH-). Methods: In a database comprising demographic and clinical data of 273 pediatric PFAPA patients treated at two tertiary centers in Israel, 31 (14.3%) had FH+. Data from patients with FH+ were compared to data from those with FH-. Furthermore, family members (FMs) of those with FH+ were contacted via telephone for more demographic and clinical details. Results: The FH+ group as compared to the FH- group had more myalgia (56 vs. 19%, respectively, p = 0.001), headaches (32 vs. 2%, respectively, p = 0.016), and a higher carrier frequency of M694V mutation (54% vs. 25%, respectively, p = 0.05). Colchicine was seen to be a more beneficial treatment for the FH+ group as compared to the FH- group; however, with no statistical significance (p = 0.096). FMs displayed almost identical characteristics to patients in the FH+ group except for greater arthralgia during flares (64 vs. 23%, respectively, p = 0.008), and compared to the FH- group they had more oral aphthae (68 vs. 43%, respectively, p = 0.002), myalgia/arthralgia (64 vs. 19%/16%, respectively, p < 0.0001), and higher rates of FH of Familial Mediterranean fever (FMF) (45 vs.15%, respectively, p = 0.003). Conclusions: Our findings suggest that patients with a FH+ likely experience a different subset of disease with higher frequency of family history of FMF, arthralgia, myalgia, and might have a better response to colchicine compared to FH-. Colchicine prophylaxis for PFAPA should be considered in FH+.

Differential effects of the G118R, H51Y, and E138K resistance substitutions in different subtypes of HIV integrase.

UNLABELLED: Dolutegravir (DTG) is the latest antiretroviral (ARV) approved for the treatment of human immunodeficiency virus (HIV) infection. The G118R substitution, previously identified with MK-2048 and raltegravir, may represent the initial substitution in a dolutegravir resistance pathway. We have found that subtype C integrase proteins have a low enzymatic cost associated with the G118R substitution, mostly at the strand transfer step of integration, compared to either subtype B or recombinant CRF02_AG proteins. Subtype B and circulating recombinant form AG (CRF02_AG) clonal viruses encoding G118R-bearing integrases were severely restricted in their viral replication capacity, and G118R/E138K-bearing viruses had various levels of resistance to dolutegravir, raltegravir, and elvitegravir. In cell-free experiments, the impacts of the H51Y and E138K substitutions on resistance and enzyme efficiency, when present with G118R, were highly dependent on viral subtype. Sequence alignment and homology modeling showed that the subtype-specific effects of these mutations were likely due to differential amino acid residue networks in the different integrase proteins, caused by polymorphic residues, which significantly affect native protein activity, structure, or function and are important for drug-mediated inhibition of enzyme activity. This preemptive study will aid in the interpretation of resistance patterns in dolutegravir-treated patients. IMPORTANCE: Recognized drug resistance mutations have never been reported for naive patients treated with dolutegravir. Additionally, in integrase inhibitor-experienced patients, only R263K and other previously known integrase resistance substitutions have been reported. Here we suggest that alternate resistance pathways may develop in non-B HIV-1 subtypes and explain how "minor" polymorphisms and substitutions in HIV integrase that are associated with these subtypes can influence resistance against dolutegravir. This work also highlights the importance of phenotyping versus genotyping when a strong inhibitor such as dolutegravir is being used. By characterizing the G118R substitution, this work also preemptively defines parameters for a potentially important pathway in some non-B HIV subtype viruses treated with dolutegravir and will aid in the inhibition of such a virus, if detected. The general inability of strand transfer-related substitutions to diminish 3' processing indicates the importance of the 3' processing step and highlights a therapeutic angle that needs to be better exploited.

Biochemical analysis of the role of G118R-linked dolutegravir drug resistance substitutions in HIV-1 integrase.

Drug resistance mutations (DRMs) have been reported for all currently approved anti-HIV drugs, including the latest integrase strand transfer inhibitors (INSTIs). We previously used the new INSTI dolutegravir (DTG) to select a G118R integrase resistance substitution in tissue culture and also showed that secondary substitutions emerged at positions H51Y and E138K. Now, we have characterized the impact of the G118R substitution, alone or in combination with either H51Y or E138K, on 3' processing and integrase strand transfer activity. The results show that G118R primarily impacted the strand transfer step of integration by diminishing the ability of integrase-long terminal repeat (LTR) complexes to bind target DNA. The addition of H51Y and E138K to G118R partially restored strand transfer activity by modulating the formation of integrase-LTR complexes through increasing LTR DNA affinity and total DNA binding, respectively. This unique mechanism, in which one function of HIV integrase partially compensates for the defect in another function, has not been previously reported. The G118R substitution resulted in low-level resistance to DTG, raltegravir (RAL), and elvitegravir (EVG). The addition of either of H51Y or E138K to G118R did not enhance resistance to DTG, RAL, or EVG. Homology modeling provided insight into the mechanism of resistance conferred by G118R as well as the effects of H51Y or E138K on enzyme activity. The G118R substitution therefore represents a potential avenue for resistance to DTG, similar to that previously described for the R263K substitution. For both pathways, secondary substitutions can lead to either diminished integrase activity and/or increased INSTI susceptibility.