Trends in preterm birth in women living with HIV in Switzerland over the last three decades: A multicentric, prospective, cohort study.

BACKGROUND: HIV infection and its management during pregnancy to reduce perinatal transmission has been associated with preterm birth (PTB). This management has drastically changed. We aimed to evaluate changes in rates of PTB over 34 years in women living with HIV (WLWH) in Switzerland, and to identify factors and interventions associated with these changes. METHODS: We analysed data from 1238 singleton pregnancies, prospectively collected by the Swiss Mother and Child HIV Cohort Study (MoCHiV) and the Swiss HIV Cohort Study (SHCS) between 1986 and 2020. Rates of PTB in this cohort were compared with that of the general Swiss population for three time periods according to changing treatment strategies recommended at the time. We evaluated the association of PTB with sociodemographic, HIV infection and obstetric variables in uni- and multivariate logistic regression. RESULTS: Rate of PTB in WLWH was highest prior to 2010 (mean 20.4%), and progressively decreased since then (mean 11.3%), but always remained higher than in the general population (5%). Older maternal age, lower CD4 count and detectable viraemia at third trimester (T3), drug consumption and mode of delivery were all significantly associated with both PTB and period of study in univariate analysis. There was no association between PTB and type of antiretroviral regimen. No difference was found in the rate of spontaneous labor between PTB and term delivery groups. Only higher CD4 count at T3 and vaginal delivery were significantly associated with a decrease in PTB over time in multivariate analysis. CONCLUSIONS: Preterm birth in WLWH in Switzerland has drastically decreased over the last three decades, but remains twice the rate of that in the general population. Improved viral control and changes in mode of delivery (vaginal birth recommended if viral loads are low near birth) have led to this progress.

Investigation of an international water polo tournament in Czechia as a potential source for early introduction of the SARS-CoV-2 Omicron variant into Belgium, Switzerland and Germany, November 2021.

BackgroundThe earliest recognised infections by the SARS-CoV-2 Omicron variant (Pango lineage B.1.1.529) in Belgium and Switzerland suggested a connection to an international water polo tournament, held 12-14 November 2021 in Brno, Czechia.AimTo study the arrival and subsequent spread of the Omicron variant in Belgium and Switzerland, and understand the overall importance of this international sporting event on the number of infections in the two countries.MethodsWe performed intensive forward and backward contact tracing in both countries, supplemented by phylogenetic investigations using virus sequences of the suspected infection chain archived in public databases.ResultsThrough contact tracing, we identified two and one infected athletes of the Belgian and Swiss water polo teams, respectively, and subsequently also three athletes from Germany. In Belgium and Switzerland, four and three secondary infections, and three and one confirmed tertiary infections were identified. Phylogenetic investigation demonstrated that this sporting event played a role as the source of infection, but without a direct link with infections from South Africa and not as a superspreading event; the virus was found to already be circulating at that time in the countries involved.ConclusionThe SARS-CoV-2 Omicron variant started to circulate in Europe several weeks before its identification in South Africa on 24 November 2021. Accordingly, it can be assumed that travel restrictions are usually implemented too late to prevent the spread of newly detected SARS-CoV-2 variants to other regions. Phylogenetic analysis may modify the perception of an apparently clear result of intensive contact tracing.

Immunologic and Genetic Contributors to CD46-Dependent Immune Dysregulation.

Mutations in CD46 predispose to atypical hemolytic uremic syndrome (aHUS) with low penetrance. Factors driving immune-dysregulatory disease in individual mutation carriers have remained ill-understood. In addition to its role as a negative regulator of the complement system, CD46 modifies T cell-intrinsic metabolic adaptation and cytokine production. Comparative immunologic analysis of diseased vs. healthy CD46 mutation carriers has not been performed in detail yet. In this study, we comprehensively analyzed clinical, molecular, immune-phenotypic, cytokine secretion, immune-metabolic, and genetic profiles in healthy vs. diseased individuals carrying a rare, heterozygous CD46 mutation identified within a large single family. Five out of six studied individuals carried a CD46 gene splice-site mutation causing an in-frame deletion of 21 base pairs. One child suffered from aHUS and his paternal uncle manifested with adult-onset systemic lupus erythematosus (SLE). Three mutation carriers had no clinical evidence of CD46-related disease to date. CD4+ T cell-intrinsic CD46 expression was uniformly 50%-reduced but was comparable in diseased vs. healthy mutation carriers. Reconstitution experiments defined the 21-base pair-deleted CD46 variant as intracellularly-but not surface-expressed and haploinsufficient. Both healthy and diseased mutation carriers displayed reduced CD46-dependent T cell mitochondrial adaptation. Diseased mutation carriers had lower peripheral regulatory T cell (Treg) frequencies and carried potentially epistatic, private rare variants in other inborn errors of immunity (IEI)-associated proinflammatory genes, not found in healthy mutation carriers. In conclusion, low Treg and rare non-CD46 immune-gene variants may contribute to clinically manifest CD46 haploinsufficiency-associated immune-dysregulation.

Viral suppression and retention in HIV care during the postpartum period among women living with HIV: a longitudinal multicenter cohort study.

Background: Low rates of postnatal retention in HIV care and viral suppression have been reported in women living with HIV (WLWH) despite viral suppression at delivery. At the same time, postpartum follow-up is of crucial importance in light of the increasing support offered in many resource-rich countries including Switzerland to WLWH choosing to breastfeed their infant, if optimal scenario criteria are met. Methods: We longitudinally investigated retention in HIV care, viral suppression, and infant follow-up in a prospective multicentre HIV cohort study of WLWH in the optimal scenario who had a live birth between January 2000 and December 2018. Risk factors for adverse outcomes in the first year postpartum were assessed using logistic and proportional hazard models. Findings: Overall, WLWH were retained in HIV care for at least six months after 94.2% of the deliveries (694/737). Late start of combination antiretroviral therapy (cART) during the third trimester was found to be the main risk factor for failure of retention in HIV care (crude odds ratio [OR] 3.91; 95% confidence interval [CI], 1.50-10.22; p = 0.005). Among mothers on cART until at least one year after delivery, 4.4% (26/591) experienced viral failure, with illicit drugs use being the most important risk factor (hazard ratio [HR], 13.2; 95% CI, 2.35-73.6; p = 0.003). The main risk factors for not following the recommendations regarding infant follow-up was maternal depression (OR, 3.52; 95% CI, 1.18-10.52; p = 0.024). Interpretation: Although the results are reassuring, several modifiable risk factors for adverse postpartum outcome, such as late treatment initiation and depression, were identified. These factors should be addressed in HIV care of all WLWH, especially those opting to breastfeed in resource-rich countries. Funding: This study has been financed within the framework of the Swiss HIV Cohort Study, supported by the Swiss National Science Foundation (grant #201369), by SHCS project 850 and by the SHCS research foundation.

Aerococcus urinae - significance of detection in the paediatric urinary tract: a case series.

Aerococcus urinae (A. urinae) is primarily recognized as a common pathogen in the geriatric population, causing urinary tract infection (UTI), sepsis, and endocarditis, predominantly in female patients. In the paediatric population, only a few case reports exist suggesting A. urinae causes malodorous urine in otherwise healthy boys. In this study, we investigated the spectrum of clinical and laboratory presentations of A. urinae detection in children. A retrospective, single-centre, case series including all patients with the detection of A. urinae during a 7-year study period. Patients with detection of A. urinae only in non-urogenital skin swabs were excluded. A total of 40 samples from 33 patients were identified of which 20 patients were included in the final analysis. The median (IQR) age was 6.8 (2.9-9.5) years; 18 (90%) patients were boys. Four patients were diagnosed with a UTI, six had malodorous urine without UTI, three were diagnosed with balanitis and seven showed A. urinae colonization in the urine culture. Urogenital disorders were present in 12 patients. Additional pathogens were detected in 13 patients. Recurrence of detection during our study period was observed in four (20%) patients.  Conclusion: Beyond malodorous urine, A. urinae detection is associated with more severe presentations including UTI in the paediatric population. Pre-existing urogenital disorders were frequent, and therefore, a nephro-urological investigation should be considered in all cases of A. urinae detection in the paediatric population. What is Known: • Aerococcus urinae (A. urinae) is known to be a common pathogen in the geriatric population, causing urinary tract infection (UTI), sepsis, and endocarditis, predominantly in female patients. • In the paediatric population, A. urinae is mainly described as a low-grade pathogen. Some case reports describe A. urinae as the cause of extraordinary malodorous urine in otherwise healthy boys. What is New: • Beyond malodorous urine, A. urinae detection is associated with more severe presentations including UTI in the paediatric population. • A. urinae was mainly detected in boys with pre-existing urogenital disorders; therefore, a nephro-urological investigation should be considered in cases of A. urinae detection in the paediatric population.

Giant Bilateral Hydronephrosis in A Newborn-A Case Report.

BACKGROUND: Prenatal hydronephrosis is common and may vary in size. Although mostly unproblematic, it may be a sign of urinary tract obstruction of differing severity. CASE DIAGNOSIS/TREATMENT: We present a boy with prenatally detected bilateral giant hydronephrosis. A prenatal ultrasound showed the whole abdominal cavity of the fetus filled with urine. Kidney parenchyma could not be seen. The boy was born at 34 + 1 weeks' gestation. After delivery, he showed a severely distended abdomen. Insertion of a nasogastric tube was not possible, and he had to be intubated due to respiratory distress. A bilateral percutaneous nephrostomy was performed immediately. After a few hours, he could be stabilized and extubated. An ultrasound on the following day showed two kidney units with normal kidney parenchyma of normal size. The initially slightly elevated serum creatinine level normalized within one week. An antegrade pyelography via the nephrostomy tubes showed bilateral ureteropelvic junction obstruction. CONCLUSION: Severe bilateral hydronephrosis may be associated with good outcome and well-preserved kidney function. Prenatal counseling should be done carefully, with discussion of different treatment possibilities and without definitive prediction of outcome.

Diagnostic accuracy of an interdisciplinary tertiary center evaluation in children referred for suspected congenital anomalies of the kidney and urinary tract on fetal ultrasound - a retrospective outcome analysis.

BACKGROUND: Fetal ultrasound organ screening has become a standard of care in most high-income countries. This has resulted in increased detection of congenital abnormalities, which may lead to major uncertainty and anxiety in expectant parents, even though many of them are of minor relevance. In order to optimize prenatal counselling, we introduced an interdisciplinary approach for all pregnant women referred to our center by private obstetricians for a co-assessment of suspected relevant fetal abnormalities of the kidney or urinary tract, involving both experienced prenatal ultrasound specialists and a pediatric nephrologist or urologist. METHODS: In a retrospective analysis, we evaluated reports of intrauterine evaluation and postnatal follow-up in order to assess accuracy of explicit intrauterine diagnoses and outcome of hydronephroses according to their severity in this setting. RESULTS: A total of 175 fetuses were examined between 2012 and 2019 and followed postnatally at our Pediatric Nephrology or Urology Department. There was a high concordance (85.9%) between explicit intrauterine and final diagnoses. Resolution rate of hydronephrosis was higher in patients with intrauterine low-grade than high-grade hydronephrosis (61.8% versus 11.9%). An etiological diagnosis was found in 62.5%, 52.0%, and 11.1% of patients with intrauterine bilateral high-grade, unilateral high-grade, and unilateral high-grade with contralateral low-grade hydronephrosis, respectively, but in none of the patients with intrauterine low-grade hydronephrosis. CONCLUSIONS: The results of our study demonstrate that, through interdisciplinary teamwork, intrauterine assessment of the fetal kidneys and urinary tract is highly accurate and allows a good discrimination between relevant and transient/physiological hydronephroses. A higher resolution version of the Graphical abstract is available as Supplementary information.

Defects in KCNJ16 Cause a Novel Tubulopathy with Hypokalemia, Salt Wasting, Disturbed Acid-Base Homeostasis, and Sensorineural Deafness.

BACKGROUND: The transepithelial transport of electrolytes, solutes, and water in the kidney is a well-orchestrated process involving numerous membrane transport systems. Basolateral potassium channels in tubular cells not only mediate potassium recycling for proper Na+,K+-ATPase function but are also involved in potassium and pH sensing. Genetic defects in KCNJ10 cause EAST/SeSAME syndrome, characterized by renal salt wasting with hypokalemic alkalosis associated with epilepsy, ataxia, and sensorineural deafness. METHODS: A candidate gene approach and whole-exome sequencing determined the underlying genetic defect in eight patients with a novel disease phenotype comprising a hypokalemic tubulopathy with renal salt wasting, disturbed acid-base homeostasis, and sensorineural deafness. Electrophysiologic studies and surface expression experiments investigated the functional consequences of newly identified gene variants. RESULTS: We identified mutations in the KCNJ16 gene encoding KCNJ16, which along with KCNJ15 and KCNJ10, constitutes the major basolateral potassium channel of the proximal and distal tubules, respectively. Coexpression of mutant KCNJ16 together with KCNJ15 or KCNJ10 in Xenopus oocytes significantly reduced currents. CONCLUSIONS: Biallelic variants in KCNJ16 were identified in patients with a novel disease phenotype comprising a variable proximal and distal tubulopathy associated with deafness. Variants affect the function of heteromeric potassium channels, disturbing proximal tubular bicarbonate handling as well as distal tubular salt reabsorption.

Swiss consensus recommendations on urinary tract infections in children.

The kidneys and the urinary tract are a common source of infection in children of all ages, especially infants and young children. The main risk factors for sequelae after urinary tract infections (UTI) are congenital anomalies of the kidney and urinary tract (CAKUT) and bladder-bowel dysfunction. UTI should be considered in every child with fever without a source. The differentiation between upper and lower UTI is crucial for appropriate management. Method of urine collection should be based on age and risk factors. The diagnosis of UTI requires urine analysis and significant growth of a pathogen in culture. Treatment of UTI should be based on practical considerations regarding age and presentation with adjustment of the initial antimicrobial treatment according to antimicrobial sensitivity testing. All children, regardless of age, should have an ultrasound of the urinary tract performed after pyelonephritis. In general, antibiotic prophylaxis is not recommended.Conclusion: Based on recent data and in line with international guidelines, multidisciplinary Swiss consensus recommendations were developed by members of Swiss pediatric infectious diseases, nephrology, and urology societies giving the clinician clear recommendations in regard to diagnosis, type and duration of therapy, antimicrobial treatment options, indication for imaging, and antibiotic prophylaxis. What is Known: • Urinary tract infections (UTI) are a common and important clinical problem in childhood. Although children with pyelonephritis tend to present with fever, it can be difficult on clinical grounds to distinguish cystitis from pyelonephritis, particularly in young children less than 2 years of age. • Method of urine collection is based on age and risk factors. The diagnosis of UTI requires urine analysis and significant growth of a pathogen in culture. What is New: • Vesicoureteric reflux (VUR) remains a risk factor for UTI but per se is neither necessary nor sufficient for the development of renal scars. Congenital anomalies of the kidney and urinary tract (CAKUT) and bladder-bowel dysfunction play a more important role as causes of long-term sequelae. In general, antibiotic prophylaxis is not recommended. • A switch to oral antibiotics should be considered already in young infants. Indications for invasive imaging are more restrictive and reserved for patients with abnormal renal ultrasound, complicated UTI, and infections with pathogens other than E. coli.

Treatment of opioid withdrawal in neonates with morphine, phenobarbital, or chlorpromazine: a randomized double-blind trial.

Three suitable compounds (morphine, chlorpromazine, and phenobarbital) to treat neonatal abstinence syndrome were compared in a prospective multicenter, double-blind trial. Neonates exposed to opioids in utero were randomly allocated to one of three treatment groups. When a predefined threshold of a modified Finnegan score was reached, treatment started and increased stepwise until symptoms were controlled. If symptoms could not be controlled with the predefined maximal dose of a single drug, a second drug was added. Among 143 infants recruited, 120 needed pharmacological treatment. Median length of treatment for morphine was 22 days (95% CI 18 to 33), for chlorpromazine 25 days (95% CI 21 to 34), and for phenobarbital 32 days (95% CI 27 to 38) (p = ns). In the morphine group, only 3% of infants (1/33) needed a second drug; in the chlorpromazine group, this proportion was 56% (24/43), and in the phenobarbital group 30% (13/44).Conclusion: None of the drugs tested for treating neonatal abstinence syndrome resulted in a significantly shorter treatment length than the others. As morphine alone was able to control symptoms in almost all infants, it may be preferred to the two other drugs but should still be tested against more potent opioids such as buprenorphine.Trial registration: At ClinicalTrials.gov NCT02810782 (registered retrospectively).What is Known:• Neonates exposed to opiates in utero and presenting with withdrawal symptoms should first be treated by non-pharmacological supportive measures.• In those who fail, drugs have to be given, but there is controversy which drug is best.What is New:• Among three candidates, morphine, chlorpromazine and phenobarbital, none resulted in significantly shorter treatment time.• As morphine alone was able to control symptoms in almost all infants, it may be preferred to the two other drugs.

The rate of mother-to-child transmission of antiretroviral drug-resistant HIV strains is low in the Swiss Mother and Child HIV Cohort Study.

AIMS OF THE STUDY: Combination antiretroviral therapy (cART) has reduced mother-to-child transmissions (MTCT) and improved the prognosis of HIV-infected newborns. However, drug resistance mutations (DRM) in HIV-infected children, either transmitted by MTCT (HIV-tDRM) or selected by suboptimal adherence and drug levels (HIV-sDRM), remain a concern. We sought to determine the rate of HIV-tDRM and HIV-sDRM in MTCT pairs in Switzerland. METHODS: We performed a retrospective analysis of prospectively collected clinical data and available stored samples from MTCT pairs participating in the Swiss Mother-Child HIV (MoCHIV) cohort. RESULTS: We identified 22 HIV-infected mother-child pairs with delivery between 1989 and 2009 who had 15 years of follow-up (33% white ethnicity). Twenty-one women (96%) were treatment-naïve before pregnancy, 8 (36%) had an unknown HIV status and delivered vaginally, 2 were diagnosed but not treated, and 11 (50%) received antiretrovirals during pregnancy or at delivery, of whom only 6 cases (27%) had cART. HIV subtypes were concordant in all mother-child pairs (subtype B 13/22 [59%]). Using stored plasma (n = 66) and mononuclear cell (n = 43) samples from the children, HIV-tDRM (M184V) was identified in 1 of 22 (4.5%) mothers (1/11 treated, 9%) and was followed by HIV-sDRM at 10 months of age. HIV-sDRM (M184V 23%; K103N 4.5%; D67N 13.6%) occurred in 16/22 (73%) after 4 years, half of whom were treatment naïve. HIV-sDRM were associated with a lower CD4 T-cell nadir (p <0.05) and tended to have higher viral loads and more frequent cART changes. CONCLUSIONS: HIV-tDRM were low in this Swiss MoCHIV cohort, making them a minor yet preventable complication of prenatal HIV care, whereas HIV-sDRM are a significant challenge in paediatric HIV care.

Is breastfeeding an equipoise option in effectively treated HIV-infected mothers in a high-income setting?

Combined antiretroviral treatment (cART) has reduced mother-to-child transmission (MTCT) of the human immunodeficiency virus (HIV) to virtually zero in industrialised countries, where strictly bottle feeding is recommended for HIV-infected mothers, and to as low as 0.7% after 12 months in low-resource settings, where breastfeeding is strongly encouraged. Given the theoretically very low risk of transmission by breastfeeding with cART, and the advantages and benefits of breastfeeding, also in industrialised countries, the strong recommendation to HIV-infected mothers to refrain from breastfeeding in this setting may no longer be justified. We have evaluated risks of breastfeeding for HIV MTCT in the light of accessible cART, the general benefits of breastfeeding, and the women's autonomy to consent to any intervention. As we found no evidence in the literature of HIV MTCT via breastfeeding whilst on effective cART, we identified a situation of clinical equipoise. We propose how to proceed in Switzerland when HIV-infected women consider breastfeeding. We advocate a shared decision-making process and suggest a list of topics on which to provide unbiased information for the HIV-infected mother to enable her comprehensive understanding of one or the other decision. Although breastfeeding still should not be actively recommended in Switzerland, any HIV-infected mother, regardless of her geographical and cultural background, who decides to breastfeed should be supported by the best strategy to achieve optimal medical care for both herself and her child. This includes continuous support of cART adherence and regular maternal HIV plasma viral load monitoring.

Severe Disruption of Water and Electrolyte Balance After Appendectomy: A Case Report.

Perioperative derangements of fluid and electrolyte homeostasis are rare complications in healthy children. Nonetheless, early diagnosis and treatment are mandatory to avoid a potentially life-threatening situation. However, the variety of underlying pathologies may prove to make accurate diagnosis challenging. This case report presents the management of an unexpected occurrence of a perioperative partial diabetes insipidus with massive fluid loss. Diagnostic and therapeutic procedures are discussed in the context of laboratory findings, and an overview of the existing literature is given. Finally, we emphasize that a multidisciplinary approach is most appropriate for diagnosis, accurate treatment, and follow-up of the patient.

Decline of Seroprevalence and Incidence of Congenital Toxoplasmosis Despite Changing Prevention Policy-Three Decades of Cord-blood Screening in North-western Switzerland.

BACKGROUND: Due to the lack of prospective data, there is an ongoing debate about the need for screening and prevention programs for congenital toxoplasmosis in Europe. Accordingly, individual countries have chosen different public health strategies. METHODS: A cord-blood screening program for congenital toxoplasmosis was established in 1982 in obstetric units of hospitals in North-Western Switzerland. Samples were tested for specific immunoglobulin G (IgG) and IgM, and after 1992 also for IgA antibodies. Suspicious test results triggered additional investigations to identify children with congenital toxoplasmosis. RESULTS: From 1982 to 2015, 119,166 cord-blood samples have been collected and analyzed for the presence of Toxoplasma-specific antibodies. Although maternal age rose from 28.2 to 32.2 years during this period, a decrease of seroprevalence from 53% to 20% was observed. The incidence of congenital toxoplasmosis decreased by 85% (from 0.08% to 0.012%) and remained low despite abandoning prevalent nonsystematic screening during pregnancy in Switzerland. CONCLUSIONS: Our data document a steady decline of both Toxoplasma gondii seroprevalence and congenital toxoplasmosis incidence in Switzerland even after abolition of the nonsystematic prenatal screening a decade ago. The data support abandoning toxoplasmosis screening programs in low-incidence, high-income countries such as Switzerland.

Optimizing seroprotection against pneumococcus in children with nephrotic syndrome using the 13-valent pneumococcal conjugate vaccine.

BACKGROUND: Infections are among the main life-threatening complications in patients with nephrotic syndrome (NS), in particular with Streptococcus pneumoniae, the first cause of bacterial peritonitis and sepsis in these patients. This study aims to evaluate the baseline seroprotection of NS patients against S. pneumoniae, and immunize them with the 13-valent pneumococcal conjugate vaccine (PCV13) regardless of disease activity and previous immunization history, in order to evaluate the immunogenicity, safety profile, and effect of NS treatment on vaccine responses. METHODS: This multicentre prospective interventional study enrolled 42 children with NS at disease onset or during a regular follow-up appointment. PCV13 was administered at inclusion. Serotype-specific S. pneumoniae IgG titer were assessed at baseline, after immunization, and at 1year follow-up. Vaccine safety was evaluated clinically and by urinary tests. RESULTS: PCV13 induced high serotype-specific IgG titers that were maintained at high levels one year after vaccination, even in children previously immunized. No serious adverse event occurred and relapse frequency was unchanged. CONCLUSION: Given that high IgG titers were achieved and maintained after PCV13 vaccination, and considering the high morbidity related to S. pneumoniae, we propose PCV13 (re-)vaccination for all NS patients, irrespective of their previous immunization history, treatment and disease activity.

Tumor-associated FGF-23-induced hypophosphatemic rickets in children: a case report and review of the literature.

BACKGROUND: Tumor-associated fibroblast growth factor 23 (FGF-23)-induced hypophosphatemic rickets is a rare but known pediatric entity first described in 1959. It results from local production of phosphatonins by benign and malignant mesenchymal tumors. CASE-DIAGNOSIS/TREATMENT: We report an 8-year-old boy with tumor-associated hypophosphatemic rickets due to paraneoplastic FGF-23 secretion from a benign mesenchymal pelvic-bone tumor. Excessive FGF-23 production was visualized by immunohistochemistry in the resected tumor. Phosphate wasting stopped immediately after tumor resection. We reviewed 26 reports of pediatric patients with tumor-induced hypophosphatemic rickets; paraneoplastic FGF-23 secretion was documented in only three of them. All tumors developed inside bone, were benign in 21/26 cases, and were localized in femur/tibia (13/26), radius/ulna/humerus (7/26), pelvis (4/26), rib (1/26), and craniofacial (1/26) bones. Mean interval between onset of signs and/or symptoms and diagnosis was 34 months. CONCLUSIONS: In patients with hypophosphatemic rickets acquired beyond infancy, radiologic investigations for bone tumors need to be performed rapidly. In contrast to biochemical screening for increased circulating FGF-23 levels, immunohistochemical confirmation of FGF-23 production in resected tumor tissue can be regarded as being well established.