Secondary bacterial infections & extensively drug-resistant bacteria among COVID-19 hospitalized patients at the University Hospital in Kraków.

INTRODUCTION: Healthcare-associated infections (HAI) and bacterial antimicrobial resistance posed a therapeutic risk during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to analyze the HAIs in COVID-19 patients in the Intensive Care Unit (ICU) and non-ICU at the University Hospital in Krakow (UHK) with an emphasis on the susceptibility of the most frequently isolated pathogens and the prevalence of extensively drug resistant (XDR) microorganisms. METHODS: This laboratory-based study was carried out at the University Hospital in Krakow in the ICU and non-ICUs dedicated to COVID-19 patients between May 2021 and January 2022. All isolates of Klebsiella pneumoniae were analyzed using PFGE protocol. RESULTS: 292 independent HAI cases were identified, with the predominance of urinary tract infections (UTI), especially in the non-ICU setting. The most common ICU syndrome was pneumonia (PNA). The prevalence of XDR organisms was 22.6% in the ICU and 14.8% in non-ICUs among all isolates. The incidence of carbapenem-resistant Enterobacteriaceae infection was 24.8 cases per 10,000 hospitalizations and the carbapenem-resistant A. baumannii infection incidence was 208.8 cases per 10,000 hospitalizations. The prevalence of XDR strains was highest in Acinetobacter spp, in PNA cases. The PFGE typing demonstrated that almost all XDR strains varied widely from each other. CONCLUSIONS: In this study, there was a high incidence of HAI in COVID-19 patients, especially when compared to Western Europe and the United States. Similarly, the prevalence of XDR microorganisms, especially XDR-A.baumannii, was also high. PFGE did not confirm the horizontal spread of any organism strains.

Final results from the large sunitinib global expanded-access trial in metastatic renal cell carcinoma.

BACKGROUND: We report final results with extended follow-up from a global, expanded-access trial that pre-regulatory approval provided sunitinib to metastatic renal cell carcinoma (mRCC) patients, ineligible for registration-directed trials. METHODS: Patients ⩾18 years received oral sunitinib 50 mg per day on a 4-weeks-on-2-weeks-off schedule. Safety was assessed regularly. Tumour measurements were scheduled per local practice. RESULTS: A total of 4543 patients received sunitinib. Median treatment duration and follow-up were 7.5 and 13.6 months. Objective response rate was 16% (95% confidence interval (CI): 15-17). Median progression-free survival (PFS) and overall survival (OS) were 9.4 months (95% CI: 8.8-10.0) and 18.7 months (95% CI: 17.5-19.5). Median PFS in subgroups of interest: aged ⩾65 years (33%), 10.1 months; Eastern Cooperative Oncology Group performance status ⩾2 (14%), 3.5 months; non-clear cell histology (12%), 6.0 months; and brain metastases (7%), 5.3 months. OS was strongly associated with the International Metastatic Renal-Cell Carcinoma Database Consortium prognostic model (n=4065). The most common grade 3/4 treatment-related adverse events were thrombocytopenia (10%), fatigue (9%), and asthenia, neutropenia, and hand-foot syndrome (each 7%). CONCLUSION: Final analysis of the sunitinib expanded-access trial provided a good opportunity to evaluate the long-term side effects of a tyrosine kinase inhibitor used worldwide in mRCC. Efficacy and safety findings were consistent with previous results.

Efficacy and safety of sunitinib in elderly patients with metastatic renal cell carcinoma.

BACKGROUND: We retrospectively analyzed sunitinib outcome as a function of age in metastatic renal cell carcinoma (mRCC) patients. METHODS: Data were pooled from 1059 patients in six trials. Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS) were compared by log-rank test between patients aged <70 (n=857; 81%) and ≥70 (n=202; 19%) years. RESULTS: In first-line patients, median PFS was comparable in younger and older patients, 9.9 vs 11.0 months, respectively (HR, 0.89; 95% CI: 0.73-1.09; P=0.2629), as was median OS, 23.6 vs 25.6 months (HR, 0.93; 95% CI: 0.74-1.18; P=0.5442). Similarly, in cytokine-refractory patients, median PFS was 8.1 vs 8.4 months (HR, 0.79; 95% CI: 0.49-1.28; P=0.3350), while median OS was 20.2 vs 15.8 months (HR, 1.14; 95% CI: 0.73-1.79; P=0.5657). Some treatment-emergent adverse events were significantly less common in younger vs older patients, including fatigue (60% vs 69%), cough (20% vs 29%), peripheral edema (17% vs 27%), anemia (18% vs 25%), decreased appetite (13% vs 29%), and thrombocytopenia (16% vs 25%; all P<0.05). Hand-foot syndrome was more common in younger patients (32% vs 24%). CONCLUSIONS: Advanced age should not be a deterrent to sunitinib therapy and elderly patients may achieve additional clinical benefit.

Prognostic factors for survival in 1059 patients treated with sunitinib for metastatic renal cell carcinoma.

BACKGROUND: Prognostic factors for progression-free survival (PFS), overall survival (OS), and long-term OS (≥30 months) were investigated in sunitinib-treated patients with metastatic renal cell carcinoma (RCC). METHODS: Data were pooled from 1059 patients in six trials. Baseline variables, including ethnicity, were analysed for prognostic significance by Cox proportional-hazards model. RESULTS: Median PFS and OS were 9.7 and 23.4 months, respectively. Multivariate analysis of PFS and OS identified independent predictors, including ethnic origin, Eastern Cooperative Oncology Group performance status, time from diagnosis to treatment, prior cytokine use, haemoglobin, lactate dehydrogenase, corrected calcium, neutrophils, platelets, and bone metastases (OS only). Characteristics of long-term survivors (n=215, 20%) differed from those of non-long-term survivors; independent predictors of long-term OS included ethnic origin, bone metastases, and corrected calcium. There were no differences in PFS (10.5 vs 7.2 months; P=0.1006) or OS (23.8 vs 21.4 months; P=0.2135) in white vs Asian patients; however, there were significant differences in PFS (10.5 vs 5.7 months; P<0.001) and OS (23.8 vs 17.4 months; P=0.0319) in white vs non-white, non-Asian patients. CONCLUSION: These analyses identified risk factors to survival with sunitinib, including potential ethnic-based differences, and validated risk factors previously reported in advanced RCC.

Sunitinib objective response in metastatic renal cell carcinoma: analysis of 1059 patients treated on clinical trials.

BACKGROUND: Retrospective analyses were performed in patients with metastatic renal cell carcinoma (mRCC) to characterise the objective response (OR) rate to sunitinib and differentiate pretreatment features and outcomes of patients with early (response by ≤ 12 weeks) versus late response, and responders versus non-responders. METHODS: Data were pooled from 1059 patients in six trials. Median progression-free survival (PFS) and overall survival (OS) were estimated by Brookmeyer and Crowley method and compared between groups by log-rank test. Baseline characteristics were compared by Fisher-exact, t-, or Wilcoxon rank-sum tests. Associations between characteristics and survival were investigated by Cox proportional regression analysis. RESULTS: 398 patients (38%) had confirmed OR (12 complete responses); 26%, 61%, 79% and 86% responded by 6, 12, 18 and 24 weeks, respectively. Median (range) time to tumour response (TTR) was 10.6 (2.7-94.4) weeks and was similar in treatment-naïve and cytokine-refractory patients. Median response duration in early and late responders was 52.0 and 55.0 weeks, respectively. Median PFS in early versus late responders was 13.8 versus 20.2 months (P=0.001); however, median OS did not significantly differ (37.8 versus 40.8 months; P=0.144). Early responders had more lung metastases (P<0.01), but baseline characteristics were otherwise mostly similar. Median PFS (16.3 versus 5.3 months) and OS (40.1 versus 14.5 months) were longer in responders versus non-responders (both P<0.001); responders had more favourable prognostic factors. CONCLUSIONS: OR occurred in 38% of sunitinib-treated mRCC patients. Sixty-one percent of responses occurred by 12 weeks of therapy, and responders had favourable pretreatment features and significantly longer survival.

Resistance against syncytium-inducing human immunodeficiency virus type 1 (HIV-1) in selected CD4(+) T cells from an HIV-1-infected nonprogressor: evidence of a novel pathway of resistance mediated by a soluble factor(s) that acts after virus entry.

A panel of CD4(+) T-cell clones were generated from peripheral blood lymphocytes from a patient with a nonprogressing infection of human immunodeficiency virus type 1 (HIV-1) by using herpesvirus saimiri as described recently. By and large, all of the clones expressed an activated T-cell phenotype (Th class 1) and grew without any further stimulation in interleukin-2-containing medium. None of these clones produced HIV-1, and all clones were negative for HIV-1 DNA. When these clones were infected with primary and laboratory (IIIB) strains of HIV-1 with syncytium-inducing (SI) phenotypes, dramatic variation of virus production was observed. While two clones were highly susceptible, other clones were relatively or completely resistant to infection with SI viruses. The HIV-resistant clones expressed CXCR4 coreceptors and were able to fuse efficiently with SI virus env-expressing cells, indicating that no block to virus entry was present in the resistant clones. Additionally, HIV-1 DNA was detectable after infection of the resistant clones, further suggesting that HIV resistance occurred in these clones after virus entry and probably after integration. We further demonstrate that the resistant clones secrete a factor(s) that can inhibit SI virus production from other infected cells and from a chronically infected producer cell line. Finally, we show that the resistant clones do not express an increased amount of ligands (stromal-derived factor SDF-1) of CXCR4 or other known HIV-inhibitory cytokines. Until now, the ligands of HIV coreceptors were the only natural substances that had been shown to play antiviral roles of any real significance in vivo. Our data from this study show that differential expression of another anti-HIV factor(s) by selected CD4(+) T cells may be responsible for the protection of these cells against SI viruses. Our results also suggest a novel mechanism of inhibition of SI viruses that acts at a stage after virus entry.

Janus kinase 2 is involved in stromal cell-derived factor-1alpha-induced tyrosine phosphorylation of focal adhesion proteins and migration of hematopoietic progenitor cells.

Stromal cell-derived factor-1 (SDF-1), the ligand for the CXCR4 receptor, is a highly efficacious chemoattractant for CD34(+) hematopoietic progenitor cells. However, the SDF-1/CXCR4 signaling pathways that regulate hematopoiesis are still not well defined. This study reports that SDF-1alpha can stimulate the tyrosine phosphorylation of Janus kinase 2 (JAK2) and other members of the JAK/signal transduction and activation of transcription (STAT) family, including JAK1, tyrosine kinase 2, STAT2, and STAT4 in the human progenitor cell line, CTS. SDF-1alpha stimulation of these cells also enhanced the association of JAK2 with phosphatidylinositol 3 (PI3)-kinase. This enhanced association was abolished by pretreatment of cells with AG490, a specific JAK2 inhibitor. Furthermore, pretreatment of CTS cells with AG490 significantly inhibited SDF-1alpha-induced PI3-kinase activity, and inhibition of JAK2 with AG490 ablated the SDF-1alpha-induced tyrosine phosphorylation of multiple focal adhesion proteins (including focal adhesion kinase, related adhesion focal tyrosine kinase, paxillin, CrkII, CrkL, and p130Cas). Chemotaxis assays showed that inhibition of JAK2 diminished SDF-1alpha-induced migration in both CTS cells and CD34(+) human bone marrow progenitor cells. Hence, these results suggest that JAK2 is required for CXCR4 receptor-mediated signaling that regulates cytoskeletal proteins and cell migration through PI3-kinase pathways in hematopoietic progenitor cells. (Blood. 2001;97:3342-3348)

Humanization of an antibody recognizing a breast cancer specific epitope by CDR-grafting.

BACKGROUND: Muc1-H23 is a cell surface mucin that is expressed on normal breast luminal epithelial cells and over-expressed in most breast tumors. In addition, Muc-1 expressed by malignant cells is glycosylated differently than Muc-1 expressed by normal cells. This difference in glycosylation exposes a peptide epitope on malignant cells which is not exposed on normal cells. Murine monoclonal antibody H23 recognizes this epitope and stains 91% of breast cancers, but only 1/56 non-malignant breast tissue samples. OBJECTIVE: To create a human antibody that was equivalent to H23 for potential uses in imaging and/or the therapy of breast cancer. STUDY DESIGN: We decided to humanize H23 by CDR-grafting using overlap PCR, and to this end, designed and constructed a bacterial expression vector that would allow V-regions, cloned via unique restriction sites, to be expressed as Fab fragments. In this way, we hoped to be able to rapidly evaluate Fab constructs for binding to Muc-1 and to cells and tissue sections that expressed the antigen. RESULTS: A fully humanized Fab fragment was able to bind Muc-1 peptide, as well as breast cancer cells known to express the epitope and tissue sections, generally showing the same reactivity as the native antibody. In addition, an analysis of sFab expressed with a [His]6 tag preceded by a factor Xa proteolytic cleavage site suggested that E. coli periplasmic signal peptidase was able to cleave the factor Xa site, thereby removing the [His]6 tag. CONCLUSION: We have generated a human antibody that is capable of recognizing a tumor specific epitope expressed by 91% of breast cancers.