Nirmatrelvir/ritonavir treatment in SARS-CoV-2 positive kidney transplant recipients - a case series with four patients.

BACKGROUND: Despite vaccination coronavirus disease 2019 (COVID-19)-associated mortality caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains high in kidney transplant recipients. Nirmatrelvir is a protease inhibitor with activity against SARS-CoV-2. Nirmatrelvir reduces the risk for mortality and hospitalization, which is approved for treating adults at risk for severe disease. Nirmatrelvir is metabolized by the cytochrome P-450 (CYP) 3A4 isozyme CYP3A4 and is therefore co-administered with the irreversible CYP3A4 inhibitor ritonavir, which results in a drug interaction with tacrolimus. A limited number of patients with nirmatrelvir/ritonavir and tacrolimus therapy after kidney transplantation have been reported to date. It has been reported that tacrolimus was paused during the five-day nirmatrelvir/ritonavir therapy and subtherapeutic tacrolimus levels were observed after finishing nirmatrelvir/ritonavir in two patients. Therefore, optimization of tacrolimus dosing is urgently needed in transplant recipients receiving nirmatrelvir/ritonavir treatment. CASE PRESENTATION: Here, we present our first-hand experience with four patients receiving tacrolimus therapy following kidney transplantation and nirmatrelvir/ritonavir therapy due to COVID-19. Tacrolimus was paused during nirmatrelvir/ritonavir therapy in all patients, which resulted in stable therapeutic tacrolimus levels. Tacrolimus was continued directly after finishing nirmatrelvir/ritonavir to avoid subtherapeutic levels in the first patient treated. This patient received his usual tacrolimus maintenance dose, which resulted in toxic levels. Based on this observation, tacrolimus therapy was continued 24 h after finishing nirmatrelvir/ritonavir treatment at a reduced dose in the subsequent patients. In these patients, therapeutic to supratherapeutic tacrolimus levels were observed despite the therapeutic break and dose reduction. DISCUSSION AND CONCLUSIONS: Based on altered CYP3A4 metabolism, tacrolimus levels have to be closely monitored after treatment with nirmatrelvir/ritonavir. Our study suggests that tacrolimus treatment should be paused during nirmatrelvir/ritonavir medication and be continued 24 h after completing nirmatrelvir/ritonavir therapy at a reduced dose and under close monitoring. Based on the limited number of patients in this study, results must be interpreted with caution.

A Unified Approach to Analysis of Body Condition in Green Toads.

Body condition is increasingly used to assess the status of populations and as a proxy for individual fitness. A common, quick and non-invasive approach is to estimate condition from the relation between body length and mass. Among the methods developed for this purpose, the Scaled Mass Index (SMI) appears best suited for comparisons among populations. We assembled data from 17 populations of European green toads (Bufotes viridis) with the aim of devising a standard formula applicable for monitoring this species. The mean value of the exponents describing length-mass allometry in these samples was 3.0047. Hence, we propose using 3 as a scaling coefficient for calculating the SMI in green toads. From the contrast of SMI values for both sexes within populations, estimated with either the population-specific or the standard coefficient, we conclude that applying the standard formula not only facilitates comparisons among populations but may also help to avoid misinterpretation of variation within populations.

Dynamic non-invasive ASL perfusion imaging of a normal pancreas with secretin augmented MR imaging.

OBJECTIVES: To investigate prospectively the repeatability of pancreatic perfusion measurements using arterial spin labelling (ASL) and to determine the increase in perfusion due to secretin stimulation. MATERIAL AND METHODS: An (FAIR)-TrueFISP ASL sequence was applied to determine the perfusion of the pancreatic head in a 3T MRI scanner. Ten healthy volunteers (four men, six women: mean age 28.5 ± 4.6 years; age range 25-40 years) were investigated twice within 1 week. The inter-individual variability was calculated using the standard deviation. Intra-individual agreement between the first and second scan was estimated using the Pearson correlation coefficient. A paired Wilcoxon rank-sum test was used to compare perfusion at baseline (BL) and during secretin stimulation. RESULTS: The mean BL perfusion of the pancreatic head was 285 ± 96 mL/100 g/min with an intra-individual correlation coefficient of 0.67 (strong) for repeated measurements. Secretin stimulation led to a significant increase (by 81%) in perfusion of the pancreatic head to 486 ±156 mL/100 g/min (p=0.002) with an intra-individual correlation of 0.29 (weak). A return to BL values was observed after 239 ± 92 s with a moderate intra-individual correlation coefficient of 0.42 for repeat measurements. CONCLUSION: Dynamic non-invasive ASL imaging of the pancreas permitted quantification of pancreatic perfusion in a clinically applicable setting. KEY POINTS: • ASL imaging of the pancreas permitted quantification of pancreatic perfusion • Secretin stimulation led to a significant increase in pancreatic perfusion • The intra-individual correlation coefficient for baseline perfusion was strong for repeated measurements.

An S-warfarin and AZD1981 interaction: in vitro and clinical pilot data suggest the N-deacetylated amino acid metabolite as the primary perpetrator.

AIM: AZD1981 is an orally bioavailable chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTh2) receptor antagonist progressed to phase II trials for the treatment of allergic asthma. Previously performed in vitro human hepatocyte incubations identified N-deacetylated AZD1981 as a primary metabolite. We report on metabolite exposure from a clinical excretion balance, on in vitro studies performed to determine the likelihood of a metabolite-dependent drug-drug interaction (DDI) and on a clinical warfarin DDI study. The aim was to demonstrate that N-deacetylated AZD1981 is responsible for the observed interaction. METHODS: The excretion and biotransformation of [14 C]-AZD1981 were studied in healthy male volunteers, and subsequently in vitro cytochrome P450 (CYP) inhibition and hepatocyte uptake investigations were carried out with metabolites and the parent drug. A clinical DDI study using coadministered twice-daily 100 mg and 400 mg AZD1981 with 25 mg warfarin was performed. RESULTS: The excretion balance study showed N-deacetylated AZD1981 to be the most abundant metabolite present in plasma. In vitro data revealed the metabolite to be a weak CYP2C9 time-dependent inhibitor, subject to more active hepatic uptake than the parent molecule. Clinically, the S-warfarin area under the plasma concentration-time curve increased, on average, 1.4-fold [95% confidence interval (CI) 1.22, 1.50] and 2.4-fold (95% CI 2.11, 2.64) after 100 mg (n = 13) and 400 mg (n = 11) AZD1981 administration, respectively. In vitro CYP inhibition and hepatocyte uptake data were used to explain the interaction. CONCLUSIONS: N-deacetylated AZD1981 can be added to the small list of drug metabolites reported as sole contributors to clinical drug-drug interactions, with weak time-dependent inhibition exacerbated by efficient hepatic uptake being the cause.

Diagnostic Value and Interreader Agreement of the Pancreaticolienal Gap in Pancreatic Cancer on MDCT.

OBJECTIVE: The aim of this retrospective study was to evaluate the diagnostic value and measure interreader agreement of the pancreaticolienal gap (PLG) in the assessment of imaging features of pancreatic carcinoma (PC) on contrast-enhanced multi-detector computed tomography (CE-MDCT). MATERIALS AND METHODS: CE-MDCT studies in the portal venous phase were retrospectively reviewed for 66 patients with PC. The age- and gender-matched control group comprised 103 healthy individuals. Three radiologists with different levels of experience independently measured the PLG (the minimum distance of the pancreatic tail to the nearest border of the spleen) in the axial plane. The interreader agreement of the PLG and the receiver operating characteristic (ROC) curve was used to calculate the accuracy of the technique. RESULTS: While the control group (n = 103) showed a median PLG of 3 mm (Range: 0 - 39mm) the PC patients had a significantly larger PLG of 15mm (Range: 0 - 53mm)(p < 0.0001). A ROC curve demonstrated a cutoff-value of >12 mm for PC, with a sensitivity of 58.2% (95% CI = 45.5-70.1), specificity of 84.0% (95% CI = 75.6-90.4) and an area under the ROC curve of 0.714 (95% CI = 0.641 to 0.780). The mean interreader agreement showed correlation coefficient r of 0.9159. The extent of the PLG did not correlate with tumor stage but did correlate with pancreatic density (fatty involution) and age, the density decreased by 4.1 HU and the PLG increased by 0.8 mm within every 10 y. CONCLUSION: The significant interreader agreement supports the use of the PLG as a characterizing feature of pancreatic cancer independent of the tumor stage on an axial plane. The increase in the PLG with age may represent physiological atrophy of the pancreatic tail.

The Treatment of Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: About one in 2000 persons in Europe suffers from autosomal dominant polycystic kidney disease (ADPKD). The treatment of this disease up to the present has been limited to the management of complications. METHODS: This review is based on pertinent publications, mostly of the last three years, that were retrieved by a selective search in PubMed. RESULTS: Kidney volume is probably the most important predictive factor for the loss of renal function. A measurement of kidney size is, therefore, recommended as soon as the diagnosis is made. ADPKD patients under age 30 with a combined kidney volume above 1500 mL and an estimated glomerular filtration rate (eGFR) below 90 mL/min are at high risk of needing kidney-replacement therapy (dialysis or transplantation) within 20 years, even if their renal function is normal. Ultrasonographic follow-up can identify affected persons whose risk for rapid progression is especially high. Currently available evidence reveals that, in patients at risk whose renal function is normal, the maintenance of blood pressure at or below a target value of 110/75 mmHg lessens renal enlargement, albuminuria, and left-ventricular hypertrophy. In another study, the treatment of selected patients with tolvaptan, a vasopressin-2 receptor (V2R) blocker, was found to delay cyst enlargement and the related decline in renal function for three years. It is unclear, however, how long the effect of tolvaptan persists, or whether persons whose renal function is already impaired can benefit from it. The main side effects are marked polyuria and, in rare cases, liver toxicity. CONCLUSION: In patients with ADPKD, an effort should be made to keep the arterial blood pressure below 120/80 mmHg. In patients at high risk of progression whose renal function is still intact (eGFR > 60 mL/min), strict blood pressure control (< 110/75 mm Hg) is indicated, and possibly V2R blockade with tolvaptan as well. Tolvaptan is an expensive drug, and patients taking it must be carefully monitored for hepatotoxicity.

Evaluation of Raman spectroscopic macro raster scans of native cervical cone biopsies using histopathological mapping.

Raman spectroscopy based discrimination of cervical precancer and normal tissue has been shown previously in vivo with fiber probe based measurements of colposcopically selected sites. With a view to developing in vivo large area imaging, macro raster scans of native cervical cone biopsies with an average of 200 spectra per sample are implemented (n=16). The diagnostic performance is evaluated using histopathological mapping of the cervix surface. Different data reduction and classification methods (principal component analysis, wavelets, k-nearest neighbors, logistic regression, partial least squares discriminant analysis) are compared. Using bootstrapping to estimate confidence intervals for sensitivity and specificity, it is concluded that differences among different spectra classification procedures are not significant. The classification performance is evaluated depending on the tissue pathologies included in the analysis using the average performance of different classification procedures. The highest sensitivity (91%) and specificity (81%) is obtained for the discrimination of normal squamous epithelium and high-grade precancer. When other non-high-grade tissue sites, such as columnar epithelium, metaplasia, and inflammation, are included, the diagnostic performance decreases.

Isthmic-vaginal smear cytology in the follow-up after radical vaginal trachelectomy for early stage cervical cancer: is it safe?

BACKGROUND: Isthmic-vaginal cytology is a follow-up method in patients who have undergone radical vaginal trachelectomy (RVT) for early cervical cancer. However, to the authors' knowledge, little is known regarding its ability to monitor patients and diagnose disease recurrence. Herein, the authors report their experience with cytology after RVT compared with cytology in patients after cone biopsy and women undergoing screening. METHODS: A database of 563 specimens from 303 patients was analyzed retrospectively (RVT in 361 specimens, conization in 102 specimens, and screening in 100 specimens). The following criteria were applied: Bethesda system, the presence of endocervical and metaplasia cells, regeneration criteria, vaginal flora, and morphological signs of human papillomavirus. The analysis was performed by 2 cytopathologists. Differences between the groups and correlation between the cytopathologists were analyzed. RESULTS: Smears without endocervical and metaplasia cells were significantly less frequent among the patients who underwent RVT. There was no difference in regeneration signs, vaginal flora, and morphologic signs of human papillomavirus between the groups. After RVT, 26/23 smears (cytopathologist 1/cytopathologist 2) smears were diagnosed as abnormal. Biopsies revealed 7 cases of dysplasia and 1 case of disease recurrence. After conization, 1 patient was diagnosed with a low-grade lesion on cytology; follow-up cytology was normal. In the screening, 10/13 smears were diagnosed with lesions on cytology; biopsy revealed dysplasia in 2 cases. The correlation between both cytopathologists was high. CONCLUSIONS: After RVT, histological verification of cytology is frequently needed. The reasons might include alterations of anatomy, regeneration, and inflammation process after RVT. Cytopathologists should become familiar with the spectrum of changes in post-RVT cytology and communication between cytopathologists and clinicians should be improved. This might reduce false-positive results.

p16INK4a and p14ARF mRNA expression in Pap smears is age-related.

Expression of high-risk HPV oncogenes results in a strong overexpression of cellular protein p16(INK4a). Immunohistochemical staining for p16(INK4a) is widely used as diagnostic marker. However, p16(INK4a) upregulation was also described as a biomarker of age. Here we analyzed p16(INK4a) expression in cervical smears to investigate if patient age may influence p16(INK4a)-based cervical cancer diagnosis. p14(ARF) was analyzed as a related supportive biomarker. Cervical scrapes were taken and stored in RNAlater. Total RNA was extracted, and cDNA was analyzed for expression of p16(INK4a) and p14(ARF) relative to ß-actin, by real-time reverse transcriptase PCR SYBR-Green I assays. Patient-derived smears referred as HSIL (n=45) had 6.27-fold higher p16(INK4a) mRNA expression than smears of cytologically normal and HPV-negative persons (n=48). Expression of p14(ARF) was 4.87-fold higher. When women with normal diagnoses were stratified for age, a significantly enhanced p16(INK4a) (2.88-fold) and p14(ARF) (1.9-fold) expression was observed as a consequence of ageing. A significant age-dependent upregulation was also observed in older HSIL patients (2.54-fold). Our study revealed significantly enhanced expression of p16(INK4a)/p14(ARF) mRNA in cervical scrapes referred to as HSIL compared with normal women. An age-dependent bias has to be considered when quantifying these tumor suppressor genes, with respect to cervical cancer development.

The prognostic significance of determining DNA content in breast cancer by DNA image cytometry: the role of high grade aneuploidy in node negative breast cancer.

AIM: To investigate the role of DNA aneuploidy, particularly in patients with node negative breast cancer, in order to identify the different risk profiles within the pool of heterogeneous breast cancers. METHODS: Imprint smears from 370 breast carcinomas were Feulgen-stained and measured by DNA image analysis. DNA aneuploidy was graded by the amount of aneuploid cells (DNA content >5c) and highly aneuploid cells (DNA content >9c) in a breast tumour population. These results were correlated to the clinical long-term follow-up. A statistical cut-off value of >10 aneuploid cells (>5c) and of >1 highly aneuploid cell (>9c) was evaluated as significant for disease-free survival (DFS) and overall survival (OS). RESULTS: Subgroups among patients with breast cancer with aneuploid cells below the cut-off value showed a significantly longer DFS and OS than those with aneuploid cells above this value. Patients with node negative breast cancer with >10 aneuploid cells (>5c) and >1 highly aneuploid cell (>9c) showed an unfavourable prognosis similar to patients with node positive breast cancer with <10 aneuploid cells (>5c) and <1 highly aneuploid tumour cell (>9c) in DFS and OS. CONCLUSION: Nuclear DNA content, as an objective marker of tumour aggressiveness, provides prognostic information in patients with both node negative and node positive breast cancer. Based on DNA aneuploidy, the clinically inhomogeneous group of patients with node negative breast cancer can be stratified into low-risk and high-risk subgroups. Therefore, DNA ploidy analysis may identify high-risk patients with lymph node negative breast cancer who might benefit from additional adjuvant therapy.

The von Hippel-Lindau tumor suppressor protein controls ciliogenesis by orienting microtubule growth.

Cilia are specialized organelles that play an important role in several biological processes, including mechanosensation, photoperception, and osmosignaling. Mutations in proteins localized to cilia have been implicated in a growing number of human diseases. In this study, we demonstrate that the von Hippel-Lindau (VHL) protein (pVHL) is a ciliary protein that controls ciliogenesis in kidney cells. Knockdown of pVHL impeded the formation of cilia in mouse inner medullary collecting duct 3 kidney cells, whereas the expression of pVHL in VHL-negative renal cancer cells rescued the ciliogenesis defect. Using green fluorescent protein-tagged end-binding protein 1 to label microtubule plus ends, we found that pVHL does not affect the microtubule growth rate but is needed to orient the growth of microtubules toward the cell periphery, a prerequisite for the formation of cilia. Furthermore, pVHL interacts with the Par3-Par6-atypical PKC complex, suggesting a mechanism for linking polarity pathways to microtubule capture and ciliogenesis.

Granulosa cell tumor of the ovary: 10 years follow-up data of 65 patients.

BACKGROUND: Granulosa cell tumor of the ovary is an uncommon neoplasm. The majority of patients are diagnosed in early stages of disease and overall prognosis is favorable. The stage at time of diagnosis is the only prognostic factor that is unequivocally related to survival. Other prognostic factors have not been well defined and are discussed in the literature controversially. MATERIALS AND METHODS: In a multi-institutional retrospective study we analyzed all relevant clinical data of patients with histologically proven granulosa cell tumor of the ovary. We applied the Kaplan-Meier method in order to estimate overall survival rates and evaluate prognostic factors. RESULTS: The median follow-up was 75 months (range, 6-315 months). Overall survival was 87% and 76% after 5 and 10 years, respectively. Eighty percent of granulosa cell tumors were diagnosed stage I (FIGO). The survival rate after recurrence was 56.8% after 10 years. Mitotic rate (p=0.003), tumor stage (p<0.001) and residual tumor disease (p<0.001) were associated with a poor prognosis (p<0.001). Age and rupture of the tumor could not be confirmed to be of prognostic value. CONCLUSION: The results of our study showed that the mitotic index may be a valuable prognostic factor. Complete tumor resection should always be attempted, since residual tumor disease is associated with a poor prognosis. Prospective studies are needed in order to confirm our findings.