On the contrary, in some patients IgG levels even decreased

Mar 17, 2023 PKM

On the contrary, in some patients IgG levels even decreased. groups were compared by Kruskal Wallis/Chi-square, and between 2 groups by Wilcoxon rank test/Chi-Square. P 0.05 were considered significant. Results 200 SpA, 95 HCW and 101 controls were recruited. Positive serology was found ILK (phospho-Ser246) antibody in 25(12.5%) SpA, 8(8.4%) HCW, 0(0%) controls (p=0.001). SpA patients with positive serology more frequently reported COVID-19-like symptoms than those with negative serology (20% 4%, p=0.009) and 2 had COVID-19 as confirmed by RT-PCR, non severe. No HCW reported symptoms or had positive RT-PCR. In SpA patients, at 3 months, mean IgM titres decreased from 2.76 2.93 to 2.38 2.95 (p=0.001), while IgG titres from 0.89 3.25 to 0.31 0.87 (p=ns). Conclusions Serology revealed that exposure to SARS-CoV-2 in SpA patients and HCW was higher than expected based on reported symptoms. In SpA, anti-cytokine therapy could act as a protective factor for a severe disease course. However, a seroconversion was not observed at 3-months. negative serology. Such considerations may not apply in other rheumatic conditions such as systemic lupus erythematosus, where a positive serology might also stem from cross-reactivity with auto-antibodies (13). However, the pathogenetic mechanism of SpA is quite different, as it mainly involves innate immunity and autoantibodies are not an issue (14). Importantly, no significant differences in the number of seropositive patients were found between SpA patients and HCW. Whether this means that SpA patients have similar seropositivity levels than general population is difficult to establish, especially since HCW are not a typical general population, due to a (theoretically) higher work-related exposure risk. However, literature indicates that patients affected rheumatic diseases seem to have the same rates of COVID-19 infection (diagnosed with nasopharyngeal swabs RT-PCR) (15). TAK-285 If this similarity will become confirmed in future serology studies as well, it will mean that immunosuppressed SpA individuals are really as revealed as general human population. Concerning the potential part of cytokine-targeted therapies in SARS-CoV-2 susceptibility, it is very interesting to notice how none of the symptomatic individuals had severe symptoms (respiratory insufficiency, fever 39, organ failure). Moreover, in the 2 2 instances of documented illness in SpA, COVID-19 experienced a slight program and hospitalization was not required, good literature describing slight/moderate disease program in immunosuppressed COVID-19 individuals with arthritis (2, 16, 17). However, some authors pointed out that the infectious disease program might be also affected by additional factors, such as age, sex, comorbidities, and even the type of immunosuppressive treatment (11, 16). In fact, medicines focusing on TNF or IL-1 and 6 might have a beneficial effect, TAK-285 as these cytokines are involved in COVID-19 pathogenesis (18). In contrast, the part of anti-IL-17 medicines is controversial: while an autoptic study of COVID-19 individuals suggested a pathogenic part for Th17 lymphocyte, therefore a potential good thing about obstructing Th17, additional studies highlighted a more severe clinical program in individuals treated with secukinumab (17, 19). Our SpA individuals with recorded COVID-19 were both on anti-TNF therapy, and indeed -as described- their disease program was slight, with symptoms like fever, malaise, myalgia, enduring only about a week. A further important point is the type and duration of the humoral response that SARS-CoV-2 can elicit: it is still unclear how regularly neutralizing antibodies are produced in response to SARS-CoV-2 illness, and whether their decrease is definitely correlated with COVID-19 severity. In fact, while some authors underlined that in milder disease program there can be a faster antibody clearance, additional studies showed persistently high levels of IgG in a broad range of COVID-19 instances, including the less severe (20, 21). In our SpA individuals, we observed a decrease in IgM titres at 3 months, which was not accompanied by and an increase in IgG. On the contrary, in some individuals IgG levels actually decreased. This result seems to indicate a failure to develop an effective and long term immune response. Whether this result is dependent on a fragile stimulation of the immune response due to low TAK-285 viral weight, or on.