Katharina Spanaus

Sirolimus and Kidney Growth in Autosomal Dominant Polycystic Kidney Disease

BACKGROUND In autosomal dominant polycystic kidney disease (ADPKD), aberrant activation of the mammalian target of rapamycin (mTOR) pathway is associated with progressive kidney enlargement. The drug sirolimus suppresses mTOR signaling. METHODS In this 18-month, open-label, randomized, controlled trial, we sought to determine whether sirolimus halts the growth in kidney volume among patients with ADPKD. We randomly assigned 100 patients between the ages of 18 and 40 years to receive either sirolimus (target dose, 2 mg daily) or standard care. All patients had an estimated creatinine clearance of at least 70 ml per minute. Serial magnetic resonance imaging was performed to measure the volume of polycystic kidneys. The primary outcome was total kidney volume at 18 months on blinded assessment. Secondary outcomes were the glomerular filtration rate and urinary albumin excretion rate at 18 months. RESULTS At randomization, the median total kidney volume was 907 cm3 (interquartile range, 577 to 1330) in the sirolimus group and 1003 cm3 (interquartile range, 574 to 1422) in the control group. The median increase over the 18-month period was 99 cm3 (interquartile range, 43 to 173) in the sirolimus group and 97 cm3 (interquartile range, 37 to 181) in the control group. At 18 months, the median total kidney volume in the sirolimus group was 102% of that in the control group (95% confidence interval, 99 to 105; P=0.26). The glomerular filtration rate did not differ significantly between the two groups; however, the urinary albumin excretion rate was higher in the sirolimus group. CONCLUSIONS In adults with ADPKD and early chronic kidney disease, 18 months of treatment with sirolimus did not halt polycystic kidney growth. (Funded by Wyeth and others; ClinicalTrials.gov number, NCT00346918.)

TNF‐α and IFN‐γ render microglia sensitive to Fas ligand‐induced apoptosis by induction of Fas expression and down‐regulation of Bcl‐2 and Bcl‐xL

The immune response in the central nervous system (CNS) involves microglial cells which represent intraparenchymal antigen‐presenting cells (APC). To control immune effector mechanisms it may be required to induce apoptosis of APC and thereby limit reactivation of T cells that have invaded the CNS. In the present study we investigated the susceptibility of primary murine microglia and of the murine microglial cell line BV‐2 to undergo Fas‐mediated apoptosis. Whereas resting microglia are resistant to Fas ligand (FasL) treatment, induction of FasL‐mediated apoptosis was achieved by treatment with TNF‐α or IFN‐γ. The effect of these cytokines was paralleled by up‐regulation of Fas expression and down‐regulation of Bcl‐2 and Bcl‐xL but not Bax. Activation of microglia by TNF‐α and IFN‐γ was also accompanied by increased amounts of mRNA for the apoptosis inhibit FLIP, an effect which did not protect the cells from FasL‐induced apoptosis. The FasL‐induced cell death pathway in microglia involves reactive oxygen intermediates because the antioxidants N‐acetyl‐cysteine and glutathione interfere with induction of apoptosis. Surprisingly, microglia constitutively express FasL on the cell surface. However, blocking of endogenous Fas‐FasL inter action with Fas‐Fc fusion protein did not enhance the survival of microglia, excluding the possibility of suicide or fratricide mechanisms. By their expression of FasL and their TNF‐α / IFN‐γ‐dependent sensitivity to the pro‐apoptotic effect of exogenous FasL, microglial cells may influence the course of T cell‐mediated diseases of the CNS.

Increases in kidney volume in autosomal dominant polycystic kidney disease can be detected within 6 months

Kidney volume growth is considered the best surrogate marker predicting the decline of renal function in autosomal dominant polycystic kidney disease. To assess the therapeutic benefit of new drugs more rapidly, changes in kidney volume need to be determined over a short time interval. Here we measured renal volume changes by manual segmentation volumetry applied to magnetic resonance imaging scans obtained with an optimized T1-weighted acquisition protocol without gadolinium-based contrast agents. One hundred young patients with autosomal dominant polycystic kidney disease and preserved renal function had a significant increase in total kidney volume by 2.71+/-4.82% in 6 months. Volume measurements were highly reproducible and accurate, as indicated by correlation coefficients of 1.000 for intra-observer and 0.996 for inter-observer agreement, with acceptable within-subject standard deviations. The change in renal volume correlated with baseline total kidney volume in all age subgroups. Total kidney volume positively correlated with male gender, hypertension, albuminuria and a history of macrohematuria but negatively with creatinine clearance. Albuminuria was associated with accelerated volume progression. Our study shows that increases in kidney volume can be reliably measured over a 6 month period in early autosomal dominant polycystic kidney disease using unenhanced magnetic resonance imaging sequences.

Cellular actors, Toll-like receptors, and local cytokine profile in acute coronary syndromes

AIMS Inflammation plays a key role in acute coronary syndromes (ACS). Toll-like receptors (TLR) on leucocytes mediate inflammation and immune responses. We characterized leucocytes and TLR expression within coronary thrombi and compared cytokine levels from the site of coronary occlusion with aortic blood (AB) in ACS patients. METHODS AND RESULTS In 18 ACS patients, thrombi were collected by aspiration during primary percutaneous coronary intervention. Thrombi and AB from these patients as well as AB from 10 age-matched controls without coronary artery disease were assessed by FACS analysis for cellular distribution and TLR expression. For further discrimination of ACS specificity, seven non-coronary intravascular thrombi and eight thrombi generated in vitro were analysed. In 17 additional patients, cytokine levels were determined in blood samples from the site of coronary occlusion under distal occlusion and compared with AB. In coronary thrombi from ACS, the percentage of monocytes related to the total leucocyte count was greater than in AB (47 vs. 20%, P = 0.0002). In thrombi, TLR-4 and TLR-2 were overexpressed on CD14-labelled monocytes, and TLR-2 was increased on CD66b-labelled granulocytes, in comparison with leucocytes in AB. In contrast, in vitro and non-coronary thrombi exhibited no overexpression of TLR-4. Local blood samples taken under distal occlusion revealed elevated concentrations of chemokines (IL-8, MCP-1, eotaxin, MIP-1alpha, and IP-10) and cytokines (IL-1ra, IL-6, IL-7, IL-12, IL-17, IFN-alpha, and granulocyte-macrophage colony-stimulating factor) regulating both innate and adaptive immunity (all P < 0.05). CONCLUSION In ACS patients, monocytes accumulate within thrombi and specifically overexpress TLR-4. Together with the local expression patterns of chemokines and cytokines, the increase of TLR-4 reflects a concerted activation of this inflammatory pathway at the site of coronary occlusion in ACS.

Serum concentrations of high–molecular weight adiponectin and their association with sex steroids in premenopausal women

At present, the association between adiponectin and sex hormones in women is controversial. Recent studies suggest that it is high-molecular weight (HMW) adiponectin and the HMW to total adiponectin ratio rather than total adiponectin that are associated with antiatherogenic activities, insulin sensitivity, metabolic syndrome, and prediction of cardiovascular events. The present study aimed to investigate whether measuring HMW adiponectin and the HMW to total adiponectin ratio rather than total adiponectin might be more useful to detect an association between circulating female sex steroids and adipocytokines. In a clinical trial, we investigated the associations of total adiponectin, HMW adiponectin, and the HMW to adiponectin ratio with several androgens and estradiol in 36 healthy premenopausal women with regular cycles. No association between the investigated sex hormones and adiponectin was observed. The HMW adiponectin was negatively correlated with estradiol after adjustment for age and body mass index. The HMW to total adiponectin ratio was significantly negatively associated with testosterone, free testosterone, and androstenedione. The testosterone to estradiol ratio, as a parameter for the estrogen-androgen balance, was not associated with adiponectin or the HMW isoform. In conclusion, there is a negative association between estradiol and HMW adiponectin, and between testosterone, free testosterone, and androstenedione and the HMW to adiponectin ratio. Thus, one mechanism whereby female sex steroids may influence the cardiovascular risk of women could be alteration of the relationship between HMW and total adiponectin concentrations in plasma.

Urinary Biomarkers at Early ADPKD Disease Stage

Background Autosomal dominant polycystic kidney disease (ADPKD) is characterized by a decline in renal function at late disease stage when the majority of functional renal parenchyma is replaced by cystic tissue. Thus, kidney function, assessed by estimated glomerular filtration rate (eGFR) does not well represent disease burden in early disease. Here, we investigated various urinary markers for tubular injury and their association with disease burden in ADPKD patients at early disease course. Methods ADPKD patients between 18 and 40 years with an eGFR greater or equal to 70 ml per min per 1.73m2 were eligible for this cross-sectional study. Urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL), Kidney Injury Molecule-1 (KIM-1), and Uromodulin (UMOD) were investigated by Enzyme-Linked Immunosorbent Assay. Clara Cell Protein 16 (CC16) was investigated by Latex Immuno Assay. Cryoscopy was performed to assess urine osmolality and Urinary Albumin-to-Creatinine Ratio (UACR) was calculated. The association and the predictive properties of the markers on eGFR and height adjusted total kidney volume (htTKV) was evaluated using multiple regression analysis, incorporating different control variables for adjustment. Internal bootstrapping validated the obtained results. Results In 139 ADPKD patients (age 31 ±7 years, mean eGFR of 93 ± 19 ml per min per 1.73 m2) the total kidney volume was negatively correlated with eGFR and UMOD and positive associated with age, UACR, KIM-1 and urine osmolality after adjustment for possible confounders. Urine osmolality and htTKV were also associated with eGFR, whereas no association of CC16, NGAL and UMOD with eGFR or htTKV was found. Conclusion UACR and urinary KIM-1 are independently associated with kidney size but not with renal function in our study population. Urine osmolality was associated with eGFR and kidney volume following adjustment for multiple confounders. Despite statistical significance, the clinical value of our results is not yet conceivable. Further studies are needed to evaluate the property of the aforementioned biomarkers to assess disease state at early ADPKD stage.

Lack of Associations between Female Hormone Levels and Visuospatial Working Memory, Divided Attention and Cognitive Bias across Two Consecutive Menstrual Cycles

Background: Interpretation of observational studies on associations between prefrontal cognitive functioning and hormone levels across the female menstrual cycle is complicated due to small sample sizes and poor replicability. Methods: This observational multisite study comprised data of n = 88 menstruating women from Hannover, Germany, and Zurich, Switzerland, assessed during a first cycle and n = 68 re-assessed during a second cycle to rule out practice effects and false-positive chance findings. We assessed visuospatial working memory, attention, cognitive bias and hormone levels at four consecutive time-points across both cycles. In addition to inter-individual differences we examined intra-individual change over time (i.e., within-subject effects). Results: Estrogen, progesterone and testosterone did not relate to inter-individual differences in cognitive functioning. There was a significant negative association between intra-individual change in progesterone and change in working memory from pre-ovulatory to mid-luteal phase during the first cycle, but that association did not replicate in the second cycle. Intra-individual change in testosterone related negatively to change in cognitive bias from menstrual to pre-ovulatory as well as from pre-ovulatory to mid-luteal phase in the first cycle, but these associations did not replicate in the second cycle. Conclusions: There is no consistent association between womens hormone levels, in particular estrogen and progesterone, and attention, working memory and cognitive bias. That is, anecdotal findings observed during the first cycle did not replicate in the second cycle, suggesting that these are false-positives attributable to random variation and systematic biases such as practice effects. Due to methodological limitations, positive findings in the published literature must be interpreted with reservation.

Fetal release of copeptin in response to maternal oxytocin administration: a randomized controlled trial

OBJECTIVE: To test whether an oxytocin challenge test raises neonatal levels of copeptin, the C-terminal portion of proarginine vasopressin, a sensitive stress marker elevated in neonates born by vaginal delivery as opposed to elective cesarean delivery. METHODS: In a randomized controlled trial in women with a singleton pregnancy undergoing elective cesarean delivery at greater than 36 weeks of gestation and no contractions or rupture of membranes, we compared arterial umbilical cord plasma concentrations of copeptin between neonates exposed to an oxytocin challenge test before elective cesarean delivery and those administered saline infusion (placebo group). Women randomized to an oxytocin challenge test received 5 international units/500 mL oxytocin Ringer lactate infused at a rate of 12 mL/h and doubled every 10 minutes until it induced three uterine contractions per 10-minute interval, at which point it was discontinued. Neonatal copeptin levels were the primary endpoint. Secondary endpoints included biochemical and physiologic parameters of fetal and maternal well-being. RESULTS: From January 2012 to October 2012 and from September 2013 to January 2015, 78 women underwent an oxytocin challenge test and 78 placebo infusion, of whom 12 and 11, respectively, were excluded as a result of insufficient blood sample volume for analysis. Umbilical cord plasma copeptin levels [median (range)] were higher in neonates who underwent an oxytocin challenge test than those who underwent placebo infusion: 22.2 (3.22–2,319) compared with 7.39 (2.5–344.6) pmol/L (P<.001). There were no statistically significant differences between the two groups in secondary outcomes. CONCLUSION: Oxytocin challenge test-induced contractions before elective cesarean delivery trigger fetal copeptin release. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT01962701.

No effect of Implanon® on inflammatory cardiovascular parameters

Objective. Recently, we found decreased levels of C-reactive protein (CRP) during use of the low-dosed contraceptive implant Implanon®. To further elucidate, whether this finding might be a sign for a lower inflammatory reaction and is associated with changes in levels of other cytokines, we investigated the effect of this implant on interleukin-6 (IL-6) and adiponectin. Plasma lipids and sex hormone levels have been shown to interact with the investigated parameters in vivo and in vitro. Therefore these parameters were measured as well. Design. Prospective case–control study. Setting. Family-planning centre, University hospital. Subjects. Thirty-six non-smoking women with regular cycles. Interventions. Blood samples for the measurements were taken in the early follicular phase of the cycle in both groups. A second sample was taken 12 weeks after Implanon insertion or in the controls during the early follicular phase of cycle 4. Results. Implanon did not cause significant changes in IL-6, adiponectin or lipoprotein (Lp)(a). At baseline, there was a significant positive correlation between IL-6 and CRP and a negative correlation between adiponectin and CRP. Conclusion. We did not observe a negative impact of Implanon on risk markers for atherosclerotic disease such as IL-6, adiponectin, and Lp(a). These data are reassuring for clinicians who prescribe progestagen-only preparations as first choice contraceptives in females with cardiovascular risk factors.

Implanon use lowers plasma concentrations of high-molecular-weight adiponectin

OBJECTIVE To investigate the effect of the low-dosed etonogestrel-releasing contraceptive implant Implanon on new cardiovascular risk markers, we studied the effect of this implant on adiponectin and its metabolically important isomer high-molecular-weight adiponectin (HMW). Low-dosed progestagen-only contraception is preferentially prescribed to females with increased cardiovascular risks. DESIGN Longitudinal study. SETTING Family-planning center of a university hospital. PATIENT(S) Forty healthy nonsmoking women with regular cycles (n=20 controls without hormonal contraception; n=20 cases wishing the insertion of Implanon). INTERVENTION(S) Blood samples for the measurements of adiponectin, HMW, C-reactive protein (CRP), sex hormone binding globulin, sexual hormones, and plasma lipids were taken in the early follicular phase of the cycle in both groups. A second sample was taken 12 weeks after Implanon insertion or in the controls during the early follicular phase of cycle four. MAIN OUTCOME MEASURE(S) At baseline there was a significant correlation between adiponectin and the parameters hsCRP and high-density lipoprotein. Implanon treatment caused a significant decrease in HMW and the HMW/adiponectin ratio. Additionally plasma lipids (cholesterol, high-density lipoprotein, low-density lipoprotein), sex hormone binding globulin, and testosterone levels decreased significantly. Adiponectin plasma concentrations were not affected. CONCLUSION(S) Short-term Implanon use in healthy premenopausal women was associated with a decrease in the cardioprotective adiponectin isomer HMW. It remains to be investigated if this decrease persists after longer use of the implant.