COVID-19 Outcomes in Kidney Transplant Recipients in a German Transplant Center.

Kidney transplant recipients (KTRs) show higher morbidity and mortality from COVID-19 than the general population and have an impaired response to vaccination. We analyzed COVID-19 incidence and clinical outcomes in a single-center cohort of approximately 2500 KTRs. Between 1 February 2020 and 1 July 2022, 578 KTRs were infected with SARS-CoV-2, with 25 (4%) recurrent infections. In total, 208 KTRs (36%) were hospitalized, and 39 (7%) died. Among vaccinated patients, infection with the Omicron variant had a mortality of 2%. Unvaccinated patients infected with the Omicron variant showed mortality (9% vs. 11%) and morbidity (hospitalization 52% vs. 54%, ICU admission 12% vs. 18%) comparable to the pre-Omicron era. Multivariable analysis revealed that being unvaccinated (OR = 2.15, 95% CI [1.38, 3.35]), infection in the pre-Omicron era (OR = 3.06, 95% CI [1.92, 4.87]), and higher patient age (OR = 1.04, 95% CI [1.03, 1.06]) are independent risk factors for COVID-19 hospitalization, whereas a steroid-free immunosuppressive regimen was found to reduce the risk of COVID-19 hospitalization (OR = 0.51, 95% CI [0.33, 0.79]). This suggests that both virological changes in the Omicron variant and vaccination reduce the risk for morbidity and mortality from COVID-19 in KTRs. Our data extend the knowledge from the general population to KTRs and provide important insights into outcomes during the Omicron era.

Pregnancy after Kidney Transplantation-Impact of Functional Renal Reserve, Slope of eGFR before Pregnancy, and Intensity of Immunosuppression on Kidney Function and Maternal Health.

Women of childbearing age show increased fertility after kidney transplantation. Of concern, preeclampsia, preterm delivery, and allograft dysfunction contribute to maternal and perinatal morbidity and mortality. We performed a retrospective single-center study, including 40 women with post-transplant pregnancies after single or combined pancreas-kidney transplantation between 2003 and 2019. Outcomes of kidney function up to 24 months after the end of pregnancy were compared with a matched-pair cohort of 40 transplanted patients without pregnancies. With a maternal survival rate of 100%, 39 out of 46 pregnancies ended up with a live-born baby. The eGFR slopes to the end of 24 months follow-up showed mean eGFR declines in both groups (-5.4 ± 14.3 mL/min in pregnant versus -7.6 ± 14.1 mL/min in controls). We identified 18 women with adverse pregnancy events, defined as preeclampsia with severe end-organ dysfunction. An impaired hyperfiltration during pregnancy was a significant risk contributor for both adverse pregnancy events (p < 0.05) and deterioration of kidney function (p < 0.01). In addition, a declining renal allograft function in the year before pregnancy was a negative predictor of worsening allograft function after 24 months of follow-up. No increased frequency of de novo donor-specific antibodies after delivery could be detected. Overall, pregnancies in women after kidney transplantation showed good allograft and maternal outcomes.

Declining Course of Humoral Immune Response in Initially Responding Kidney Transplant Recipients after Repeated SARS-CoV-2 Vaccination.

The immunogenicity of SARS-CoV-2 vaccines in kidney transplant recipients is limited, resulting in inadequately low serological response rates and low immunoglobulin (Ig) levels, correlating with reduced protection against death and hospitalization from COVID-19. We retrospectively examined the time course of anti-SARS-CoV-2 Ig antibody levels after up to five repeated vaccinations in 644 previously nonresponding kidney transplant recipients. Using anti SARS-CoV-2 IgG/IgA ELISA and the total Ig ECLIA assays, we compared antibody levels at 1 month with levels at 2 and 4 months, respectively. Additionally, we correlated the measurements of the used assays. Between 1 and 2 months, and between 1 and 4 months, mean anti-SARS-CoV-2 Ig levels in responders decreased by 14% and 25%, respectively, depending on the assay. Absolute Ig values and time course of antibody levels showed high interindividual variability. Ig levels decreased by at least 20% in 77 of 148 paired samples with loss of sufficient serological protection over time occurring in 18 out of 148 (12.2%). IgG ELISA and total Ig ECLIA assays showed a strong positive correlation (Kendall's tau = 0.78), yet the two assays determined divergent results in 99 of 751 (13.2%) measurements. IgG and IgA assays showed overall strong correlation but divergent results in 270 of 1.173 (23.0%) cases and only weak correlation of antibody levels in positive samples. Large interindividual variability and significant loss of serological response after 4 months supports repeated serological sampling and consideration of shorter vaccination intervals in kidney transplant recipients.

Serological Response to Three, Four and Five Doses of SARS-CoV-2 Vaccine in Kidney Transplant Recipients.

Mortality from COVID-19 among kidney transplant recipients (KTR) is high, and their response to three vaccinations against SARS-CoV-2 is strongly impaired. We retrospectively analyzed the serological response of up to five doses of the SARS-CoV-2 vaccine in KTR from 27 December 2020 until 31 December 2021. Particularly, the influence of the different dose adjustment regimens for mycophenolic acid (MPA) on serological response to fourth vaccination was analyzed. In total, 4277 vaccinations against SARS-CoV-2 in 1478 patients were analyzed. Serological response was 19.5% after 1203 basic immunizations, and increased to 29.4%, 55.6%, and 57.5% in response to 603 third, 250 fourth, and 40 fifth vaccinations, resulting in a cumulative response rate of 88.7%. In patients with calcineurin inhibitor and MPA maintenance immunosuppression, pausing MPA and adding 5 mg prednisolone equivalent before the fourth vaccination increased the serological response rate to 75% in comparison to the no dose adjustment (52%) or dose reduction (46%). Belatacept-treated patients had a response rate of 8.7% (4/46) after three vaccinations and 12.5% (3/25) after four vaccinations. Except for belatacept-treated patients, repeated SARS-CoV-2 vaccination of up to five times effectively induces serological response in kidney transplant recipients. It can be enhanced by pausing MPA at the time of vaccination.

Temporary antimetabolite treatment hold boosts SARS-CoV-2 vaccination-specific humoral and cellular immunity in kidney transplant recipients.

Transplant recipients exhibit an impaired protective immunity after SARS-CoV-2 vaccination, potentially caused by mycophenolate (MPA) immunosuppression. Recent data from patients with autoimmune disorders suggest that temporary MPA hold might greatly improve booster vaccination outcomes. We applied a fourth dose of SARS-CoV-2 vaccine to 29 kidney transplant recipients during a temporary (5 weeks) MPA/azathioprine hold, who had not mounted a humoral immune response to previous vaccinations. Seroconversion until day 32 after vaccination was observed in 76% of patients, associated with acquisition of virus-neutralizing capacity. Interestingly, 21/25 (84%) calcineurin inhibitor-treated patients responded, but only 1/4 belatacept-treated patients responded. In line with humoral responses, counts and relative frequencies of spike receptor binding domain-specific (RBD-specific) B cells were markedly increased on day 7 after vaccination, with an increase in RBD-specific CD27++CD38+ plasmablasts. Whereas overall proportions of spike-reactive CD4+ T cells remained unaltered after the fourth dose, frequencies were positively correlated with specific IgG levels. Importantly, antigen-specific proliferating Ki67+ and in vivo-activated programmed cell death 1-positive T cells significantly increased after revaccination during MPA hold, whereas cytokine production and memory differentiation remained unaffected. In summary, antimetabolite hold augmented all arms of immunity during booster vaccination. These data suggest further studies of antimetabolite hold in kidney transplant recipients.

Predictors of Serological Response to SARS-CoV-2 Vaccination in Kidney Transplant Patients: Baseline Characteristics, Immunosuppression, and the Role of IMPDH Monitoring.

Immunosuppression increases the risk of severe coronavirus disease 2019 (COVID-19). Morbidity and mortality of this disease in kidney transplant patients are higher than in the general population. As the vaccination response of transplant patients is weak, serological monitoring was performed. In this cohort study, we analyzed the determinants of vaccination response. All patients had no history of COVID-19. With anti-spike IgG monitoring, 148 responders and 415 non-responders were identified. We compared both groups using multivariate analyses of the cohort and a sub-cohort of mycophenolic-acid-treated patients. We investigated the influence of patient characteristics, immunosuppression, and erythrocyte inosine monophosphate dehydrogenase (IMPDH) activity. In responders, the time after transplantation was longer (13.5 vs. 8.5 years), the glomerular filtration rate was higher (56.9 vs. 47.8 mL/min/1.73 m2), and responders were younger (53.0 vs. 57.4 years). Heterologous vaccination was more effective than homologous vaccination. Calcineurin inhibitors plus mycophenolate reduced the seroconversion rate. No seroconversion was observed in belatacept patients. In mycophenolate-treated patients, IMPDH activity was a significantly better predictor of response than mycophenolate dose (AUC 0.84 vs. 0.62, p < 0.001). Immunosuppression strongly affects vaccine response. Modifications to immunosuppression should be considered in order to facilitate this response. Erythrocyte IMPDH activity can be used to guide mycophenolate treatment.

Efficacy, Retention and Tolerability of Everolimus in Patients with Tuberous Sclerosis Complex: A Survey-Based Study on Patients' Perspectives.

BACKGROUND: The approval of everolimus (EVE) for the treatment of angiomyolipoma (2013), subependymal giant cell astrocytoma (2013) and drug-refractory epilepsy (2017) in patients with tuberous sclerosis complex (TSC) represents the first disease-modifying treatment option available for this rare and complex genetic disorder. OBJECTIVE: The objective of this study was to analyse the use, efficacy, tolerability and treatment retention of EVE in patients with TSC in Germany from the patient's perspective. METHODS: A structured cross-age survey was conducted at 26 specialised TSC centres in Germany and by the German TSC patient advocacy group between February and July 2019, enrolling children, adolescents and adult patients with TSC. RESULTS: Of 365 participants, 36.7% (n = 134) reported the current or past intake of EVE, including 31.5% (n = 115) who were taking EVE at study entry. The mean EVE dosage was 6.1 ± 2.9 mg/m2 (median: 5.6 mg/m2, range 2.0-15.1 mg/m2) in children and adolescents and 4 ± 2.1 mg/m2 (median: 3.7 mg/m2, range 0.8-10.1 mg/m2) in adult patients. An early diagnosis of TSC, the presence of angiomyolipoma, drug-refractory epilepsy, neuropsychiatric manifestations, subependymal giant cell astrocytoma, cardiac rhabdomyoma and overall multi-organ involvement were associated with the use of EVE as a disease-modifying treatment. The reported efficacy was 64.0% for angiomyolipoma (75% in adult patients), 66.2% for drug-refractory epilepsy, and 54.4% for subependymal giant cell astrocytoma. The overall retention rate for EVE was 85.8%. The retention rates after 12 months of EVE therapy were higher among adults (93.7%) than among children and adolescents (88.7%; 90.5% vs 77.4% after 24 months; 87.3% vs 77.4% after 36 months). Tolerability was acceptable, with 70.9% of patients overall reporting adverse events, including stomatitis (47.0%), acne-like rash (7.7%), increased susceptibility to common infections and lymphoedema (each 6.0%), which were the most frequently reported symptoms. With a total score of 41.7 compared with 36.8 among patients not taking EVE, patients currently being treated with EVE showed an increased Liverpool Adverse Event Profile. Noticeable deviations in the sub-items 'tiredness', 'skin problems' and 'mouth/gum problems', which are likely related to EVE-typical adverse effects, were more frequently reported among patients taking EVE. CONCLUSIONS: From the patients' perspective, EVE is an effective and relatively well-tolerated disease-modifying treatment option for children, adolescents and adults with TSC, associated with a high long-term retention rate that can be individually considered for each patient. Everolimus therapy should ideally be supervised by a centre experienced in the use of mechanistic target of rapamycin inhibitors, and adverse effects should be monitored on a regular basis.

Quality of life and its predictors in adults with tuberous sclerosis complex (TSC): a multicentre cohort study from Germany.

BACKGROUND: Tuberous sclerosis complex (TSC) is a monogenetic, multisystemic disease characterised by the formation of benign tumours that can affect almost all organs, caused by pathogenic variations in TSC1 or TSC2. In this multicentre study from Germany, we investigated the influence of sociodemographic, clinical, and therapeutic factors on quality of life (QoL) among individuals with TSC. METHODS: We assessed sociodemographic and clinical characteristics and QoL among adults with TSC throughout Germany using a validated, three-month, retrospective questionnaire. We examined predictors of health-related QoL (HRQoL) using multiple linear regression analysis and compared the QoL among patients with TSC with QoL among patients with other chronic neurological disorders. RESULTS: We enrolled 121 adults with TSC (mean age: 31.0 ± 10.5 years; range: 18-61 years, 45.5% [n = 55] women). Unemployment, a higher grade of disability, a higher number of organ manifestations, the presence of neuropsychiatric manifestations or active epilepsy, and a higher burden of therapy-related adverse events were associated with worse QoL, as measured by two QoL instruments (EuroQoL-5 dimensions [EQ-5D] and Quality of Life in Epilepsy Patients [QOLIE-31]). Neuropsychiatric and structural nervous system manifestations, the number of affected organs, and therapy-related adverse events were also associated with higher depression, as measured by the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E). In multiple regression analysis, more severe therapy-related adverse events (large effect, p < 0.001), active epilepsy (large effect, p < 0.001), and neuropsychiatric manifestations (medium effect, p = 0.003) were independently associated with worse HRQoL, explaining 65% of the variance (p < 0.001). The HRQoL among patients with active TSC-associated epilepsy was worse than that among patients with drug-refractory mesial temporal lobe epilepsy (p < 0.001), and the generic QoL among patients with more than three TSC organ manifestations was similar to those of patients with severe migraine and uncontrolled asthma. CONCLUSIONS: Active epilepsy, neuropsychiatric manifestations (such as anxiety and depression), and therapy-related adverse events are important independent predictors of worse quality of life among adults with TSC. Generic quality of life in TSC with several manifestations is similar to uncontrolled severe chronic diseases and significantly negatively correlates with TSC severity. TRIAL REGISTRATION: DRKS, DRKS00016045 . Registered 01 March 2019.

Direct and indirect costs and cost-driving factors in adults with tuberous sclerosis complex: a multicenter cohort study and a review of the literature.

BACKGROUND: Tuberous sclerosis complex (TSC) is a monogenetic, multisystem disorder characterized by benign growths due to TSC1 or TSC2 mutations. This German multicenter study estimated the costs and related cost drivers associated with organ manifestations in adults with TSC. METHODS: A validated, three-month, retrospective questionnaire assessed the sociodemographic and clinical characteristics, organ manifestations, direct, indirect, out-of-pocket (OOP), and nursing care-level costs among adult individuals with TSC throughout Germany from a societal perspective (costing year: 2019). RESULTS: We enrolled 192 adults with TSC (mean age: 33.4 ± 12.7 years; range: 18-78 years, 51.6% [n = 99] women). Reported TSC disease manifestations included skin (94.8%) and kidney and urinary tract (74%) disorders, epilepsy (72.9%), structural brain defects (67.2%), psychiatric disorders (50.5%), heart and circulatory system disorders (50.5%), and lymphangioleiomyomatosis (11.5%). TSC1 and TSC2 mutations were reported in 16.7% and 25% of respondents, respectively. Mean direct health care costs totaled EUR 6452 (median EUR 1920; 95% confidence interval [CI] EUR 5533-7422) per patient over three months. Medication costs represented the major direct cost category (77% of total direct costs; mean EUR 4953), and mechanistic target of rapamycin (mTOR) inhibitors represented the largest share (68%, EUR 4358). Mean antiseizure drug (ASD) costs were only EUR 415 (6%). Inpatient costs (8%, EUR 518) and outpatient treatment costs (7%; EUR 467) were important further direct cost components. The mean care grade allowance as an approximator of informal nursing care costs was EUR 929 (median EUR 0; 95% CI EUR 780-1083) over three months. Mean indirect costs totaled EUR 3174 (median EUR 0; 95% CI EUR 2503-3840) among working-age individuals (< 67 years in Germany). Multiple regression analyses revealed mTOR inhibitor use and persistent seizures as independent cost-driving factors for total direct costs. Older age and disability were independent cost-driving factors for total indirect costs, whereas epilepsy, psychiatric disease, and disability were independent cost-driving factors for nursing care costs. CONCLUSIONS: This three-month study revealed substantial direct healthcare, indirect healthcare, and medication costs associated with TSC in Germany. This study highlights the spectrum of organ manifestations and their associated treatment needs in the German healthcare setting. TRIAL REGISTRATION: DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045 .

Digital Home-Monitoring of Patients after Kidney Transplantation: The MACCS Platform.

The MACCS (Medical Assistant for Chronic Care Service) platform enables secure sharing of key medical information between patients after kidney transplantation and physicians. Patients provide information such as vital signs, well-being, and medication intake via smartphone apps. The information is transferred directly into a database and electronic health record at the kidney transplant center, which is used for routine patient care and research. Physicians can send an updated medication plan and laboratory data directly to the patient app via this secure platform. Other features of the app are medical messages and video consultations. Consequently, the patient is better-informed, and self-management is facilitated. In addition, the transplant center and the patient's local nephrologist automatically exchange notes, medical reports, laboratory values, and medication data via the platform. A telemedicine team reviews all incoming data on a dashboard and takes action, if necessary. Tools to identify patients at risk for complications are under development. The platform exchanges data via a standardized secure interface (Health Level 7 (HL7), Fast Healthcare Interoperability Resources (FHIR)). The standardized data exchange based on HL7 FHIR guarantees interoperability with other eHealth solutions and allows rapid scalability to other chronic diseases. The underlying data protection concept is in concordance with the latest European General Data Protection Regulation. Enrollment started in February 2020, and 131 kidney transplant recipients are actively participating as of July 2020. Two large German health insurance companies are currently funding the telemedicine services of the project. The deployment for other chronic kidney diseases and solid organ transplant recipients is planned. In conclusion, the platform is designed to enable home monitoring and automatic data exchange, empower patients, reduce hospitalizations, and improve adherence, and outcomes after kidney transplantation.

Prescription patterns of antiseizure drugs in tuberous sclerosis complex (TSC)-associated epilepsy: a multicenter cohort study from Germany and review of the literature.

OBJECTIVE: Seizures are a primary and early disease manifestation of Tuberous Sclerosis Complex (TSC). We aimed to describe the age-stratified patterns of antiseizure drug (ASD) treatments among children, adolescents, and adults with TSC in Germany. Additionally, we reviewed real-world and clinical study evidence regarding ASD utilization in patients with TSC. METHODS: We evaluated the pattern of routine ASD use and everolimus prescriptions based on a 2019 multicenter survey of 268 individuals with TSC-associated epilepsy. We contextualized the results with a structured review of real-world and clinical study evidence. RESULTS: TSC-associated epilepsy treatment comprises a wide variety of ASDs. In this German sample, the majority of patients were treated with polytherapy, and lamotrigine (34.7%), valproate (32.8%), oxcarbazepine (28.7%), vigabatrin (19.0%), and levetiracetam (17.9%) were identified as the most-commonly used ASDs. In addition, everolimus was used by 32.5% of patients. In adherence to current TSC guidelines, the disease-modifying ASD vigabatrin was widely used in children (58% below the age of 5 years), whereas treatment in adults did not necessarily reflect guideline preference for (partial) GABAergic ASDs. CONCLUSIONS: The selection of ASDs for patients with TSC-associated epilepsy follows well-evaluated recommendations, including the guidelines regarding vigabatrin use in children. Several characteristics, such as the comparatively high frequency of valproate use and polytherapy, reflect the severity of TSC-associated epilepsy.

eHealth in transplantation.

eHealth ("electronic" Health) is a new field in medicine that has the potential to change medical care, increase efficiency, and reduce costs. In this review, we analyzed the current status of eHealth in transplantation by performing a PubMed search over the last 5 years with a focus on clinical studies for post-transplant care. We retrieved 463 manuscripts, of which 52 clinical reports and eight randomized controlled trials were identified. Most studies were on kidney (n = 19), followed by liver (n = 10), solid organ (n = 7), bone-marrow (n = 6), and lung transplantation (n = 6). Eleven articles included adolescents/children. Investigated eHealth features covered the whole spectrum with mobile applications for patients (n = 24) and video consultations (n = 18) being most frequent. Prominent topics for patient apps were self-management (n = 16), adherence (n = 14), symptom-reporting (11), remote monitoring of vital signs (n = 8), educational (n = 7), and drug reminder (n = 7). In this review, we discuss opportunities and strengths of such new eHealth solutions, the implications for successful implementation into the healthcare process, the human factor, data protection, and finally, the need for better evidence from prospective clinical trials in order to confirm the claims on better patient care, potential efficiency gains and cost savings.

Low Seroprevalence of SARS-CoV-2 Antibodies during Systematic Antibody Screening and Serum Responses in Patients after COVID-19 in a German Transplant Center.

The coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 denotes a global health issue. Data regarding COVID-19 incidence in kidney transplant recipients (KTR) are sparse. From 19 March to 19 May 2020, we performed a systematic screening for COVID-19 in KTR. Tests included serum analysis for SARS-CoV-2 antibodies using S protein-based immunofluorescence, anti-SARS-CoV-2 S1 immunoglobulin G (IgG) and immunoglobulin A (IgA) enzyme-linked immunosorbent assays (ELISA), and/or quantitative reverse transcription polymerase chain reaction (qRT-PCR) from nasal-throat swabs. Outpatient serum samples from KTR with PCR confirmed COVID-19, and swab samples from recipients (+donors) undergoing kidney transplantation were analyzed. Out of 223 samples from outpatients, 13 patients were positive with solely anti-SARS-CoV-2-IgA and 3 with both anti-IgA and anti-IgG. In total, 53 patients were symptomatic in the past, but positive results could be found in both symptomatic and asymptomatic patients. After an in depth analysis using immunofluorescence and neutralization tests in 2 KTR, recent COVID-19 infection remained highly suspicious. Apart from outpatient visits, only 5 out of 2044 KTR were symptomatic and tested positive via PCR, of which 4 recovered and one died. All patients showed seroconversion during the course of the disease. This study demonstrated a low seroprevalence in a German KTR cohort, and seroconversion of IgA and IgG after COVID-19 could be demonstrated. Effective containment strategies enabled us to continue our transplant program.

Everolimus in de novo kidney transplant recipients participating in the Eurotransplant senior program: Results of a prospective randomized multicenter study (SENATOR).

Early conversion to everolimus was assessed in kidney transplant recipients participating in the Eurotransplant Senior Program (ESP), a population in whom data are lacking. The SENATOR multicenter study enrolled 207 kidney transplant recipients undergoing steroid withdrawal at week 2 post-transplant (ClinicalTrials.gov [NCT00956293]). At week 7, patients were randomized (1:2 ratio) to continue the previous calcineurin inhibitor (CNI)-based regimen with mycophenolic acid (MPA) and cyclosporine or switch to a CNI-free regimen with MPA, everolimus (5-10 ng/mL) and basiliximab at weeks 7 and 12, then followed for 18 weeks to month 6 post-transplant. The primary endpoint was estimated GFR (eGFR). At week 7, 77/207 (37.2%) patients were randomized (53 everolimus, 24 control). At month 6, eGFR was comparable: 36.5±10.8ml/min with everolimus versus 42.0±13.0ml/min in the control group (p = 0.784). Discontinuation due to adverse events occurred in 27.8% of everolimus-treated patients and 0.0% of control patients (p = 0005). Efficacy profiles showed no difference. In conclusion, eGFR, safety and efficacy outcomes at month 6 post-transplant showed no difference between groups. The everolimus group experienced a higher rate of discontinuation due to adverse events. However, the high rate of non-randomization is highly relevant, indicating this to be a somewhat unstable patient population regardless of treatment.

Prophylaxis and treatment of Pneumocystis Jirovecii pneumonia after solid organ transplantation.

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection diagnosed in immunocompromized patients. After solid organ transplantation, early infection has decreased as a result of effective prophylaxis, but late infections and even outbreaks caused by interpatient transmission of pneumocystis by air are present in the SOT community. Different risk factors for PJP have been described and several indications for PJP prophylaxis have to be considered by clinicians in patients even years after transplantation. Diagnosis of PJP is confirmed by microscopy and immunofluorescence staining of bronchial fluid but PCR as well as serum ß-D-Glucan analysis have become increasingly valuable diagnostic tools. Treatment of choice is Trimethoprim/sulfamethoxazole and early treatment improves prognosis. However, mortality of PJP in solid organ transplant patients is still high and many aspects including the optimal management of immunosuppression during PJP treatment require further investigations.

Sclerotic bone lesions as a potential imaging biomarker for the diagnosis of tuberous sclerosis complex.

Tuberous-sclerosis-complex (TSC) is associated with a high lifetime risk of severe complications. Clinical manifestations are largely variable and diagnosis is often missed. Sclerotic-bone-lesions (SBL) could represent a potential imaging biomarker for the diagnosis of TSC. In this study, computed tomography (CT) data sets of 49 TSC patients (31 females) were included and compared to an age/sex matched control group. Imaging features of SBLs included frequency, size and location pattern. Sensitivities, specificities and cutoff values for the diagnosis of TSC were established for the skull, thorax, and abdomen/pelvis. In TSC patients, 3439 SBLs were detected, including 665 skull SBLs, 1426 thoracal SBLs and 1348 abdominal/pelvic SBLs. In the matched control-collective, 157 SBLs could be found. The frequency of SBLs enabled a reliable differentiation between TSC patients and the control collective with the following sensitivities and specificities. Skull: ≥5 SBLs, 0.783, 1; thorax: ≥4 SBLs, 0.967, 0.967; abdomen/pelvis: ≥5 SBLs: 0.938, 0.906. SBL size was significantly larger compared to controls (p < 0.05). Based on the frequency, size and location pattern of SBLs TSC can be suspected. SBLs may serve as a potential imaging biomarker in the workup of TSC patients.

Treatment effect of mTOR-inhibition on tissue composition of renal angiomyolipomas in tuberous sclerosis complex (TSC).

PURPOSE: Tuberous sclerosis complex (TSC)-associated renal angiomyolipoma (AML) have a high lifetime risk of acute bleeding. MTOR-inhibitors are a promising novel treatment for TSC-AML, however adequate response to therapy can be difficult to assess. Early changes in MRI signal may serve as a novel early indicator for a satisfactory response to mTOR-inhibitor therapy of AML. MATERIALS AND METHODS: Thirty-eight patients with the definite diagnosis of tuberous sclerosis receiving everolimus therapy and n = 19 patients without specific therapy were included. 1.5 Tesla MRI was performed including sequences with a selective fat suppression. Patients were investigated prior to the initiation of therapy (baseline) and after <3 months (n = 21 patients), 3 to 6 months (n = 32) and 18 to 24 months (n = 28). Signal and size changes of renal AMLs were assessed at all different timepoints. Signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR) and size of angiomyolipomas were evaluated. RESULTS: Signal changes in 273 AMLs were evaluated. A significant and strong decrease of the CNR of AMLs following the initiation of therapy was measured in the fat-suppressed MR sequence at all time points, compared to the baseline: From 7.41±6.98 to 3.84±6.25 (p ≤ 0.05p = 0.002), 3.36±6.93 (p<0.0001), and 2.50±6.68 (p<0.0001) after less than 3 months, 3-6 months or 18-24 months of everolimus treatment, respectively. Also, a significant, however less pronounced, reduction of angiomyolipoma size in the different groups was measured (from baseline 2022.2±2657.7 mm2 to 1854.4±1670.9 mm2 (p = 0.009), 1875.5±3190.1 mm2 (p<0.001), and 1365.8 ± 1628.8 mm2 (p<0.0001) after less than 3 months, 3-6 months or 18-24 months of everolimus treatment, respectively). No significant changes in CNR (p>0.05) and size (p>0.05) were measured in the control group. CONCLUSION: mTOR inhibitor therapy in TSC patients results in an early and pronounced fatty transformation of AMLs on MRI. Fatty transformation could represent a novel early indicator of response to therapy in this patient collective.