Sebastian Wortmann

Value of Fractional Uric Acid Excretion in Differential Diagnosis of Hyponatremic Patients on Diuretics

BACKGROUND The syndrome of inappropriate antidiuresis (SIAD) is the most frequent cause of hyponatremia. Its diagnosis requires decreased serum osmolality, inappropriately diluted urine (e.g. >100 mOsm/kg), clinical euvolemia, and a urinary sodium (Na) excretion (U-Na) more than 30 mmol/liter. However, in hyponatremic patients taking diuretics, this definition is unreliable due to the natriuretic effect of diuretics. Here, we examined the diagnostic potential of alternative laboratory measurements to diagnose SIAD, regardless of the use of diuretics. METHODS A total of 86 consecutive hyponatremic patients (serum Na <130 mmol/liter) was classified based on their history, clinical evaluation, osmolality, and saline response to isotonic saline into a SIAD and a non-SIAD group. U-Na, serum urate concentration, and fractional excretion (FE) of Na, urea, and uric acid (UA) were measured in all subjects. The accuracy to diagnose SIAD was assessed using receiver operating characteristic analysis. RESULTS A total of 31 patients (36%) had a diagnosis of SIAD, and 55 (64%) were classified as non-SIAD. There were 57 patients (68%) who were on diuretics (15 in the SIAD group, 42 in the non-SIAD group). In the absence of diuretic therapy, SIAD was accurately diagnosed using U-Na (area under the receiver operating characteristic curve 0.96; 0.92-1.02). However, in patients on diuretics, the diagnosis was unreliable (area under the curve 0.85; 0.73-0.97). There, FE-UA performed best compared with all other markers tested (area under the curve 0.96; 0.92-1.12), resulting in a positive predictive value of 100% if a cutoff value of 12% was used. CONCLUSION FE-UA allows the diagnosis of SIAD with excellent specificity. Combining the information on U-Na and FE-UA leads to a very high diagnostic accuracy in hyponatremic patients with and without diuretic treatment.

Treatment of advanced adrenocortical carcinoma with erlotinib plus gemcitabine.

CONTEXT Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis. In advanced disease, mitotane given as monotherapy or combined either with etoposide, doxorubicin, and cisplatin or with streptozotocin is the recommended first-line therapy. However, many patients have progressive disease despite treatment with these regimens. OBJECTIVE Our objective was to evaluate the efficacy of the epidermal growth factor receptor inhibitor erlotinib plus gemcitabine as salvage therapy in ACC patients with very advanced ACC. DESIGN/SETTING The study consisted of case series collected from different centers (primary care and referral centers) in Germany in 2006-2007. PATIENTS AND INTERVENTION Patients registered with the German ACC Registry with progressive ACC after two to four previous systemic therapies were offered treatment with erlotinib and gemcitabine. Oral erlotinib (100 mg/d) was administered on a daily basis and gemcitabine (800 mg/m(2)) iv every 14 d. MAIN OUTCOME MEASURE We evaluated tumor response according to response evaluation criteria in solid tumors (RECIST) criteria after 12 wk of treatment. RESULTS Ten patients have been treated with erlotinib and gemcitabine. Only one in 10 patients experienced a minor response (progression-free survival 8 months), whereas eight patients had progressive disease at the first staging. One patient had to stop therapy after the first administration of gemcitabine due to cerebral seizure. Nine of 10 patients had died after a median of 5.5 months after treatment initiation. In addition to the seizure, one patient experienced severe pneumonia (grade III), and in one, gemcitabine administration had been delayed due to prolonged neutropenia. All other adverse events were mild (grade I-II). CONCLUSIONS Salvage chemotherapy using erlotinib plus gemcitabine has very limited to no activity in patients with very advanced ACC.

Bevacizumab plus capecitabine as a salvage therapy in advanced adrenocortical carcinoma

OBJECTIVE No standard therapy for advanced adrenocortical carcinoma (ACC) is established by any randomized trial but a consensus conference 2003 recommended mitotane as monotherapy or combined with etoposide, doxorubicin and cisplatin or with streptozotocin as first-line systemic therapy. However, there is no evidence for any therapy beneficial in patients failing these therapies. Therefore, we evaluated the effects of the anti-VEGF antibody bevacizumab plus capecitabine as salvage therapy in ACC. METHODS Patients registered with the German ACC Registry with refractory ACC progressing after cytotoxic therapies were offered treatment with bevacizumab (5 mg/kg body weight i.v. every 21 days) and oral capecitabine (950 mg/m(2) twice daily for 14 days followed by 7 days of rest) in 2006-2008. Evaluation of tumour response was performed by imaging according to response evaluation criteria in solid tumours every 12 weeks. RESULTS Ten patients were treated with bevacizumab plus capecitabine. None of them experienced any objective response or stable disease. Two patients had to stop therapy after few weeks due to hand-foot syndrome, and three patients died on progressive disease within 12 weeks. Other adverse events were mild (grade I-II). Median survival after treatment initiation was 124 days. CONCLUSIONS Bevacizumab plus capecitabine has no activity in patients with very advanced ACC. Hence, this regimen cannot be recommended as a salvage therapy.

Glucose transporter GLUT1 expression is an stage-independent predictor of clinical outcome in adrenocortical carcinoma

Owing to the rarity of adrenocortical carcinoma (ACC) no prognostic markers have been established beyond stage and resection status. Accelerated glycolysis is a characteristic feature of cancer cells and in a variety of tumour entities key factors in glucose metabolism like glucose transporter 1 and 3 (GLUT1 and -3), transketolase like-1 enzyme (TKTL1) and pyruvate kinase type M2 (M2-PK) are overexpressed and of prognostic value. Therefore, we investigated the role of these factors in ACC. Immunohistochemical analysis was performed on tissue microarrays of paraffin-embedded tissue samples from 167 ACCs, 15 adrenal adenomas and 4 normal adrenal glands. Expression was correlated with baseline parameters and clinical outcome. GLUT1 and -3 were expressed in 33 and 17% of ACC samples respectively, but in none of the benign tumours or normal adrenals glands. By contrast, TKTL1 and M2-PK were detectable in all benign tissues and the vast majority of ACCs. GLUT1 expression was strongly associated with prognosis in univariate and multivariate analysis (P<0.01), whereas GLUT3, TKTL1 and M2-PK did not correlate with clinical outcome. Patients with strong GLUT1 staining showed a considerably higher overall mortality (hazard ratio (HR) 6.34 (95% confidence interval 3.10-12.90) compared with patients with no GLUT1 staining. When analysing patients in their early stages and advanced disease separately, similar results were obtained. HR for survival was 5.31 (1.80-15.62) in patients with metastatic ACC and in patients after radical resection the HR for disease-free survival was 6.10 (2.16-16.94). In conclusion, GLUT1 is a highly promising stage-independent, prognostic marker in ACC.

Expression of excision repair cross complementing group 1 and prognosis in adrenocortical carcinoma patients treated with platinum-based chemotherapy

Therapeutic progress in adrenocortical carcinoma (ACC) is severely hampered by its low incidence. Platinum-based chemotherapies are the most effective cytotoxic treatment regimens in ACC but response rates remain <50%. In other tumor entities, expression of excision repair cross complementing group 1 (ERCC1) predicts resistance to platinum compounds. Therefore, we correlated ERCC1 protein expression and clinical outcome. We have retrolectively established adrenal tissue microarrays and analyzed prospectively samples from 163 ACCs, 15 benign adrenal adenomas, and 8 normal adrenal glands by immunohistochemistry for ERCC1 protein expression. Detailed clinical data were available by the German ACC Registry. ERCC1 protein was highly expressed in all normal adrenal glands, 14 benign tumors (93%) and in 75 ACCs (47%). In ACC, no differences in baseline parameters were found between patients with and without ERCC1 expression. Detection of ERCC1 was not correlated with survival in patients who never received platinum-based chemotherapy. In platinum-treated patients (n=45), objective response to platinum compounds was observed in 3/21 patients (14.3%) with high ERCC1 expression and in 7/24 patients (29.2%) with low ERCC1 expression (P=0.23). ERCC1 expression was strongly correlated with overall survival after platinum treatment (median: eight months in patients with high ERCC1 versus 24 months in low ERCC1 expression, hazard ratio (HR) 2.95 (95% confidence interval (CI) 1.4-6.2), P=0.004). Multivariate analysis confirmed that high ERCC1 expression was a predictive factor for poor prognosis in platinum treated patients (HR 2.2, 95% CI 1.0-4.5, P=0.038). Our findings suggest that ERCC1 expression is the first factor for predicting survival in ACC patients treated with platinum-based chemotherapy.

Influence of Short-Term Glucocorticoid Therapy on Regulatory T Cells In Vivo

Background Pre- and early clinical studies on patients with autoimmune diseases suggested that induction of regulatory T(Treg) cells may contribute to the immunosuppressive effects of glucocorticoids(GCs). Objective We readdressed the influence of GC therapy on Treg cells in immunocompetent human subjects and naïve mice. Methods Mice were treated with increasing doses of intravenous dexamethasone followed by oral taper, and Treg cells in spleen and blood were analyzed by FACS. Sixteen patients with sudden hearing loss but without an inflammatory disease received high-dose intravenous prednisolone followed by stepwise dose reduction to low oral prednisolone. Peripheral blood Treg cells were analyzed prior and after a 14 day GC therapy based on different markers. Results Repeated GC administration to mice for three days dose-dependently decreased the absolute numbers of Treg cells in blood (100 mg dexamethasone/kg body weight: 2.8±1.8×104 cells/ml vs. 33±11×104 in control mice) and spleen (dexamethasone: 2.8±1.9×105/spleen vs. 95±22×105/spleen in control mice), which slowly recovered after 14 days taper in spleen but not in blood. The relative frequency of FOXP3+ Treg cells amongst the CD4+ T cells also decreased in a dose dependent manner with the effect being more pronounced in blood than in spleen. The suppressive capacity of Treg cells was unaltered by GC treatment in vitro. In immunocompetent humans, GCs induced mild T cell lymphocytosis. However, it did not change the relative frequency of circulating Treg cells in a relevant manner, although there was some variation depending on the definition of the Treg cells (FOXP3+: 4.0±1.5% vs 3.4±1.5%*; AITR+: 0.6±0.4 vs 0.5±0.3%, CD127low: 4.0±1.3 vs 5.0±3.0%* and CTLA4+: 13.8±11.5 vs 15.6±12.5%; * p<0.05). Conclusion Short-term GC therapy does not induce the hitherto supposed increase in circulating Treg cell frequency, neither in immunocompetent humans nor in mice. Thus, it is questionable that the clinical efficacy of GCs is achieved by modulating Treg cell numbers.