Inference and forecasting phase shift regime of COVID-19 sub-lineages with a Markov-switching model

IMPORTANCE

Using regime-switching models, we attempted to determine whether there is a link between changes in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) variants and infection waves, as well as forecasting new SARS-Cov-2 variants. We believe that our study makes a significant contribution to the field because it proposes a new approach for forecasting the ongoing pandemic, and the spread of other infectious diseases, using a statistical model which incorporates unpredictable factors such as human behavior, political factors, and cultural beliefs.

Occurrence of human leukocyte antigen B51-related ankylosing spondylitis in a family: Two case reports

BACKGROUND

Ankylosing spondylitis (AS) is strongly associated with the human leukocyte antigen (HLA) B27 haplotype. In regions where conventional polymerase chain reaction for HLA typing is available for antigens such as HLA B27 or HLA B51, it is common to perform the HLA B27 test for evaluation of AS. While HLA B27-associated clustered occurrences of AS have been reported in families, we report the first case series of HLA B51-related occurrences of AS in a family.

CASE SUMMARY

A father and his daughters were diagnosed with AS and did not have the HLA B27 haplotype. Although they were positive for HLA B51, they exhibited no signs of Behçet’s disease (BD). Of the five daughters, one had AS, and three, including the daughter with AS, were positive for HLA B51. The two daughters with the HLA B51 haplotype (excluding the daughter with AS) exhibited bilateral grade 1 sacroiliitis, whereas the daughters without the HLA B51 haplotype did not have sacroiliitis. Thus, this Korean family exhibited a strong association with the HLA B51 haplotype and clinical sacroiliitis, irrespective of the symptoms of BD.

CONCLUSION

It is advisable to check for HLA B51 positivity in patients with AS/spondyloarthropathy who test negative for HLA B27.

Evaluation of the predictors of readmission in Korean patients with heart failure

WHAT IS KNOWN AND OBJECTIVE

Various factors contribute to the high rate of readmission among patients hospitalized with heart failure (HF). Determination of these factors is fundamental to identify potential targets for intervention in hospitalized patients.

METHODS

The retrospective cohort study used a large national insurance database to identify episodes of HF. Clinical information up to 12 months from the index hospitalization was obtained. Depending on their outcome, eligible patients were classified into a 30-day readmission group after discharge or a non-readmission group. Potential predictors of 30-day readmission were categorized by patient, drug therapy and health system utilization factors.

RESULTS AND DISCUSSION

Heart failure was identified in 19 128 inpatients. Of these, 27·6% were readmitted within 30 days after discharge. The mean Charlson comorbidity index (CCI) score was 5·2 ± 2·9 for the readmission group and 4·3 ± 2·5 for the non-readmission group. The strongest predictors included paralysis [adjusted odds ratio (AOR) 2·27, 95% confidence interval (CI) 1·97-2·62], followed by metastatic cancer (AOR 2·22, 95% CI 1·81-2·72) and loop diuretic therapy (AOR 1·52, 95% CI 1·29-1·79). A prescription of ACE inhibitor or angiotensin receptor blocker at discharge was associated with a 17% decreased risk (AOR 0·83, 95% CI 0·77-0·89).

WHAT IS NEW AND CONCLUSIONS

Hospitalized patients with HF have a 30-day all-cause readmission rate exceeding a quarter. Post-discharge care should focus on patients with advanced age, acuity of admission, enrolled medical aid, hospitalization exceeding 14 days, higher CCI score, more than 10 prescription drugs at discharge, presence of several comorbidities and loop diuretic therapy, which are independent predictors for 30-day readmission.

Gefitinib targets ZAP-70-expressing chronic lymphocytic leukemia cells and inhibits B-cell receptor signaling

Chronic lymphocytic leukemia (CLL) can be divided into groups based on biomarkers of poor prognosis. The expression of the tyrosine kinase ZAP-70 (member of the Syk tyrosine kinase family) in CLL cells is associated with shorter overall survival in CLL patients. Currently, there is a lack of targeted therapies for patients with ZAP-70 expression in CLL cells. The tyrosine kinase inhibitor gefitinib has been shown to be effective at induce apoptosis in acute myeloid leukemia through inhibition of Syk. In this study, we sought to test the efficacy of gefitinib in primary human ZAP-70+ CLL cells. We demonstrate that gefitinib preferentially induces cell death in ZAP-70-expressing CLL cells with a median IC₅₀ of 4.5 μM. In addition, gefitinib decreases the viability of ZAP-70+ Jurkat T leukemia cells but fails to affect T cells from CLL patients. Western blot analysis shows gefitinib reduces both basal and B-cell receptor (BCR)-stimulated phosphorylation of Syk/ZAP-70, ERK, and Akt in ZAP-70+ CLL cells. Moreover, gefitinib inhibits the pro-survival response from BCR stimulation and decreases pro-survival proteins such as Mcl-1. Finally, ZAP-70 expression sensitizes Raji cells to gefitinib treatment. These results demonstrate that gefitinib specifically targets ZAP-70+ CLL cells and inhibits the BCR cell survival pathway leading to apoptosis. This represents the likelihood of tyrosine kinase inhibitors being effective targeted treatments for ZAP-70+ CLL cells.