PSMA PET/CT Versus mpMRI for the Detection of Clinically Significant Prostate Cancer: An Updated Overview

In the last years, PSMA-PET imaging and multiparametric MRI (mpMRI) have improved the clinical management of prostate cancer (PCa) patients. Currently, mpMRI is recommended by the EAU (European Association of Urology) guidelines for the primary diagnosis of PCa, whereas PSMA-PET is reserved for disease staging, particularly in high risk localized or locally advanced disease, as well as for biochemical recurrence after surgery. Nevertheless, several studies have explored the added value of PSMA-PET in other clinical scenarios, including primary diagnosis and especially for the detection of clinically significant PCa (csPCa). In the present contribution, we will provide an overview and an update on the current literature on imaging detection of csPCa, with a particular focus on mpMRI, PSMA-PET and their comparison.

Comparison of MRI vs. [18F]FDG PET/CT for Treatment Response Evaluation of Primary Breast Cancer after Neoadjuvant Chemotherapy: Literature Review and Future Perspectives

The purpose of this systematic review was to investigate the diagnostic accuracy of [18F]FDG PET/CT and breast MRI for primary breast cancer (BC) response assessment after neoadjuvant chemotherapy (NAC) and to evaluate future perspectives in this setting. We performed a critical review using three bibliographic databases (i.e., PubMed, Scopus, and Web of Science) for articles published up to the 6 June 2023, starting from 2012. The Quality Assessment of Diagnosis Accuracy Study (QUADAS-2) tool was adopted to evaluate the risk of bias. A total of 76 studies were identified and screened, while 14 articles were included in our systematic review after a full-text assessment. The total number of patients included was 842. Eight out of fourteen studies (57.1%) were prospective, while all except one study were conducted in a single center. In the majority of the included studies (71.4%), 3.0 Tesla (T) MRI scans were adopted. Three out of fourteen studies (21.4%) used both 1.5 and 3.0 T MRI and only two used 1.5 T. [18F]FDG was the radiotracer used in every study included. All patients accepted surgical treatment after NAC and each study used pathological complete response (pCR) as the reference standard. Some of the studies have demonstrated the superiority of [18F]FDG PET/CT, while others proved that MRI was superior to PET/CT. Recent studies indicate that PET/CT has a better specificity, while MRI has a superior sensitivity for assessing pCR in BC patients after NAC. The complementary value of the combined use of these modalities represents probably the most important tool to improve diagnostic performance in this setting. Overall, larger prospective studies, possibly randomized, are needed, hopefully evaluating PET/MR and allowing for new tools, such as radiomic parameters, to find a proper place in the setting of BC patients undergoing NAC.

[18F]FDG PET-TC radiomics and machine learning in the evaluation of prostate incidental uptake

AIM

To evaluate the relevance of incidental prostate [18F]FDG uptake (IPU) and to explore the potential of radiomics and machine learning (ML) to predict prostate cancer (PCa).

METHODS

We retrieved [18F]FDG PET/CT scans with evidence of IPU performed in two institutions between 2015 and 2021. Patients were divided into PCa and non-PCa, according to the biopsy. Clinical and PET/CT-derived information (comprehensive of radiomic analysis) were acquired. Five ML models were developed and their performance in discriminating PCa vs non-PCa IPU was evaluated. Radiomic analysis was investigated to predict ISUP Grade.

RESULTS

Overall, 56 IPU were identified and 31 patients performed prostate biopsy. Eighteen of those were diagnosed as PCa. Only PSA and radiomic features (eight from CT and nine from PET images, respectively) showed statistically significant difference between PCa and non-PCa patients. Eight features were found to be robust between the two institutions. CT-based ML models showed good performance, especially in terms of negative predictive value (NPV 0.733-0.867). PET-derived ML models results were less accurate except the Random Forest model (NPV = 0.933). Radiomics could not accurately predict ISUP grade.

CONCLUSIONS

Paired with PSA, radiomic analysis seems to be promising to discriminate PCa/non-PCa IPU. ML could be a useful tool to identify non-PCa IPU, avoiding further investigations.

Role of 18F-FDG PET/CT in evaluating lymph node status in patients with head and neck squamous cell carcinoma

Objective

The presence of cervical lymph node metastases (CLNM) at diagnosis is one of the most relevant negative prognostic factors in patients with head and neck squamous cell carcinoma (HNSCC). The aim of this study was to analyse 2-deoxy-2[18F]fluoro-D-glucose (FDG) PET/CT findings for the identification of primary tumours and CLNM in a sample of patients affected by HNSCC. Moreover, a maximum standardised uptake value (SUVmax) threshold for the detection of CLNM was estimated. Clinical variables (i.e. smoking and alcohol habits), and tumour features (i.e. EBV and HPV positivity) were also evaluated in relation to FDG PET/CT findings.

Methods

We retrospectively analysed patients who underwent FDG PET/CT for HNSCC staging between 2015-2020 at the University Hospital of Ferrara. All patients had cytological or histological confirmation of suspected cervical lymph nodes.

Results

In total, 65 patients were enrolled (53 males, 12 females, median age 65.7 years). CLNM of patients with smoking habit had significantly higher SUVmax values than those of patients with previous smoking habit and non-smokers (p = 0.04). p16 positive HNSCC demonstrated a trend for higher SUVmax values on CLNM, in comparison to p16 negative tumours (p = 0.089). ROC curve analysis identified 5.8 as the best cut-off value of SUVmax for the detection of CLNM (AUC = 0.62, sensitivity 71.4% and specificity 72.7%).

Conclusions

FDG PET/CT is a useful tool to evaluate CLNM in patients with HNSCC, particularly in those with smoking habit and p16 positive disease. A SUVmax cut-off of 5.8, combined with the use of conventional radiological investigations, may represent a useful tool in the identification of CLNM.

Misinterpretation of an inflammatory FDG uptake in a patient treated for Hodgkin lymphoma: a case report

Hodgkin Lymphoma (HL) is a malignancy involving lymph nodes and lymphatic system. [¹⁸F]F-FDG PET/CT (FDG-PET) imaging is routinely used for staging, to assess early chemotherapy response (interim FDG-PET), at the end of treatment (EoT FDG-PET) and for the identification of disease recurrence. We present a case of a 39-year-old man treated for HL. FDG-PET scans performed after first line therapy (both Interim PET and at the end of therapy) demonstrated a persistent and significant mediastinal FDG uptake. The patient was treated with a second line therapy but the FDG-PET uptake did not change. After board discussion a new surgical, thoracoscopy-guided biopsy was performed. Histopathology demonstrated a dense fibrous tissue with occasional chronic inflammatory infiltrates. Persistent FDG-PET positivity may suggest refractory or relapsed disease. However, occasionally, non-malignant conditions are responsible for a persistent FDG uptake, not related to primary disease. An accurate evaluation of clinical history and previous imaging exams is mandatory for clinicians and others experts to avoid misinterpretations of FDG-PET results. Nevertheless, in some cases, only a more invasive procedure, such as a biopsy, may finally lead to a definitive diagnosis.

Incidental Findings of Acute Myeloid Leukemia in Sjögren's Syndrome Detected by Nuclear Medicine Techniques

A 46-year-old female with Sjögren's syndrome previously treated with corticosteroids was referred to our department for suspicious humeral head osteonecrosis. Dual-phase bone scan showed an increased radiotracer distribution in the head of the left humerus. Nevertheless, whole-body scan revealed multiple sites of heterogeneous skeletal uptake. As lymphoproliferative disorder was hypothesized, also based on laboratory examination, F-18 fluorodeoxyglucose positron-emission tomography/computed tomography was performed and showed increased uptake in several osseous structures and in the subcutaneous nodules. Finally, bone marrow biopsy confirmed the diagnosis of acute myeloid leukemia as well as skin nodule biopsy revealed infiltration by malignant cells.

FDG PET/CT Volume-Based Quantitative Data and Survival Analysis in Breast Cancer Patients: A Systematic Review of the Literature

PURPOSE

To assess the role of SUVs, MTV, TLG and other FDG PET metric data in predicting the prognosis of patients with newly diagnosed BC.

MATERIALS AND METHODS

A systematic review was conducted by using three different databases: PubMed, Web of Science and EMBASE, in a period between January 2011 and May 2021. Studies on the use of FDG PET in BC patients, concerning the utility of metric PET data and the survival were retrieved. The following keywords were used in diverse combinations: "breast cancer", "18F-FDG", "FDG", "PET", "PET/CT", "FDG PET", "volumetric parameters", "metabolic tumor volume", "MTV", "total lesion glycolysis", "TLG", "prognosis", "prognostic". No limits were applied. The quality of selected papers was assessed by using specific criteria.

RESULTS

Totally 123 articles were retrieved, but only 14 studies were selected. In the selected papers, overall, the number of patients was 1850. Overall survival (OS) was the main outcome in three studies, while both OS and disease-free survival (DFS) were considered in the remainder of most papers. PET/CT was performed in patients with BC, before surgery or neoadjuvant chemotherapy in 6 studies and in metastatic BC in 8. At multivariable analyses, diverse PET metrics, such as SUVmax, MTV and TLG were correlated to recurrence or OS. However, a large heterogeneity for the proposal cut-off, able to discriminate between poor and good prognosis, was found.

CONCLUSION

PET metrics are helpful for the prognosis stratification in patients with locally advanced or metastatic BC. However, no specific cut-off values for these variables are now available in this setting of patients.

Impact on the long-term prognosis of FDG PET/CT in luminal-A and luminal-B breast cancer

PURPOSE

The aim of the present study was to explore the prognostic role of 2- deoxy-2-[18F]fluoro-D-glucose PET (FDG PET)/CT in recurrent luminal A and luminal B breast cancer.

MATERIALS AND METHODS

From two institutional databases, we retrospectively retrieved data about breast cancer patients undergoing FDG PET/CT between 2011 and 2018 for the assessment of recurrency. Molecular subtypes of breast cancer were defined based on the expression of estrogen, progesterone, human epidermal growth factor receptor 2 (HER2)-b receptors and proliferation index. Overall survival (OS, intended as the time from PET/CT and the time of death) was registered for each patient, by checking the medical charts. Parametric and survival analyses were computed.

RESULTS

Data of 179 patients were retrieved. Sixty-three patients had luminal A, 88 luminal B and 28 luminal B/He breast cancer. At the time of PET/CT scan, cancer antigen (CA) 15.3 levels was within the normal range in 119 patients, whereas it was increased in 60 patients. FDG PET/CT results were suggestive for disease recurrence in 114 (63.7%) patients. The median time lapse from the FDG PET/CT scan to the last clinical follow-up visit was 51 months (1-192 months). Patients with evidence of a PET/CT scan suggestive for disease recurrence showed a significantly shorter OS (P < 0.001) compared to patients with no PET/CT evidence of recurrence, in each subset of luminal breast cancer. Moreover, PET/CT was able to stratify the prognosis of patients independently from the level of tumor marker.

CONCLUSION

These data suggest that FDG PET/CT may be an attractive prognostic tool in recurrent breast cancer. Our study supports its prognostic role both in luminal A and B-type molecular subtypes, regardless of the CA 15.3 levels.

Clinical-Diagnostic Relevance of Breast "Incidentaloma" Detected During 18F-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography: Correlation with Radiological Imaging and Histopathology

Aim:

This study aims to study the clinical-diagnostic relevance of incidental breast uptake (“incidentaloma”) on 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan performed for other indications and to correlate it with radiological imaging and histopathology.

Materials and Methods:

We retrospectively evaluated 3675 FDG-PET scans, identifying 43 patients with breast “incidentaloma.” Thirty of these findings were further investigated with clinical examination, mammography (MMX), UltraSound (US) and/or magnetic resonance (MR). Cases suspected for malignancy underwent US-guided macro-biopsy (USMB) or MR-guided biopsy. Correlations between FDG-PET, radiology findings, age, and histopathology were evaluated.

Results:

patients who performed both US and MMX were 19. Ten consequently underwent USMB, one MR-guided biopsy, the remaining 8 were not further investigated. Nine patients had a diagnosis of malignancy. Among 11 patients who performed only US and consequently, USMB 6 had a diagnosis of malignancy. Histopathology of the 22 patients with both morphological and glucometabolic alterations showed different types of benign or malignant neoplasia, with a cumulative 68.2% incidence of malignancy. Seven lesions showed a SUV_max >2.5, while the remaining 15 a SUV_max <2.5. There was no statistically significant correlation between SUV_max and histology, therefore SUV_max parameter should not be used to discriminate between benign and malignant findings. No significant correlation between patient age and tumor characterization was found.

Conclusions:

incidental mammary uptake during an FDG-PET scan may represent a clue suggesting to investigate PET findings. In this subset of patients, early diagnosis may lead to a change in clinical management with a favorable impact on prognosis and a significant reduction in healthcare costs.

P2603Impaired right ventricular force-frequency relationship in patients with heart failure is associated with diastolic dysfunction and worse functional capacity

Background

The force-frequency relationship (FFR) is an important intrinsic regulatory mechanism of cardiac contractility, related to changes in Ca2+ availability within the myocardial cell. In normal hearts this relationship is positive, so that an increase in contractile force is induced by elevation of the stimulation frequency. In heart failure (HF), the force-frequency relationship can be markedly depressed, but most studies focused their attention on left ventricular function and little is known about the right ventricle (RV).

Purpose

We aimed at performing a comprehensive analysis of HF phenotypes based on the right ventricular force-frequency relationship. To this purpose we stratified a large cohort of HF patients using the relationship between RV function (assessed by tricuspid annular plane systolic excursion, TAPSE) and heart rate (HR) during a symptom-limited cardiopulmonary exercise test (CPET).

Material and methods

We prospectively enrolled 184 HF patients, irrespective of their LV ejection fraction. We performed a stress echocardiographic evaluation using a tiltable cycle ergometer, recording standard images to assess LV systolic, diastolic, and valvular function.

We divided patients in 2 groups using the slope of the linear relationship between TAPSE and HR at rest and at peak exercise, as follows: slope ≥0,01 for “positive” FFR, slope <0,01 for “flat or negative” FFR.

Differences between groups were tested using unpaired t-tests for continuous variables (or Mann-Whitney U tests, when appropriate) and chi-square tests for categorical variables.

Results

55 patients had a “flat or negative” FFR: they were slighty older (age 70±10 vs. 66±12; p=0,036), but the 2 groups had similar clinical characteristics such as hypertension, diabetes or COPD rate.

Patients with a “flat or negative” FFR had a worse diastolic function, with higher left ventricular filling pressures (E/e' ratio 24±10 vs. 19±11 p=0,022) and left atrial volume (LAVi 55±29 ml/m2 vs. 44±20 ml/m2; p=0,009). No differences in LV ejection fraction, mitral regurgitation and pulmonary artery systolic pressure were observed between the groups.

TAPSE at rest was similar between the groups (18±5 mm vs. 18±4 mm; p=0,553) but significantly different at peak exercise (16±4 mm vs. 22±5 mm; p<0,001). Average peak heart rate was similar in the 2 groups.

Patients with a “flat or negative” FFR exhibited a significantly lower peak VO2 (11,6±3,0 ml/min/kg vs. 13,5±4,4 ml/min/kg; p=0,003), whereas they had a higher VE/VCO2 slope (35,1±9,6 vs. 32,3±8,2 p=0,05).

RV Force-Frequency relationship

Conclusion

The “flat or negative” right ventricular force-frequency relationship identifies a peculiar phenotype, with a higher grade of diastolic dysfunction and an impaired exercise capacity. The inability to adapt right ventricular contractility with increasing heart rate seems not related to RV afterload (similar PASP increase) but rather to an intrinsic failure of the right heart.

P4504Pulmonary circulatory-right ventricular uncoupling in acute decompensated heart failure: a key mediator of congestion

Background

The degree of congestion in patients hospitalized for acute decompensated heart failure (ADHF) is estimated using traditional non-invasive markers such as echo-derived inferior vena cava diameter (IVCD) and NT-proBNP levels. The deterioration of right ventricular (RV) function and its uncoupling to pulmonary circulation (Pc) represents a turning point in terms of prognosis and clinical outcome in patients affected by heart failure. However, how RV-to-Pc uncoupling correlates with markers of decompensation and congestion in ADHF patients has never been explored.

Purpose

To investigate, in a cohort of ADHF patients, the association between the degree of RV-to-Pc uncoupling, assessed by the ratio between tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP), IVCD and right atrial pressure (RAP) estimated at echocardiography.

Methods

Fourty-six ADHF patients both with reduced and preserved EF (mean age 73.15±10.85 years, 60.8% males) admitted to the Cardiology Department were prospectively enrolled within 24–48 hours from admission. In the acute phase all patients underwent transthoracic echocardiography and laboratory blood tests. Patients were then stratified in tertiles according to TAPSE/PASP ratio (group I: <0.4 mm/mmHg; group II: 0.4 to 0.6 mm/mmHg and group III: >0.6 mm/mmHg) correlating the degree of RV-to-Pc with non-invasive markers of congestion such as NT-proBNP, IVC maximum diameter and RAP. Other echocardiographic parameters including left ventricular (LV) systolic function and LV filling pressures were considered.

Results

An exponential inverse relationship was found between NT-pro-BNP levels at admission with levels decreasing progressively with the increment of the ratio (Group I: 12828±10600 ng/l; Group II 5549±5383 ng/l; Group III 3695±3870 ng/l; p=0.004) (Figure 1a). An analogous correlation was observed when considering the IVC maximum diameter (Group I: 20.87±5.37 mm; Group II 18.08±4.35 mm; Group III 10.9±3.36 mm; p<0.001) (Figure 1b) and the RAP estimated at echocardiography (Group I: 12.875±5.25 mmHg; Group II 9.157±4.82 mmHg; Group III 4±1.61 mmHg; p<0.001) (Figure 1c).

In addition, progressively increasing values of LVEF (Group I: 28±11.3%; Group II 42±17.3%; Group III 49±11.8%; p=0.001) were detected from the lowest to the highest TAPSE/PASP tertiles. No correlation was observed in the three groups for E/E' values at admission (Group I: 17.17±6.7; Group II 19.42±8.36; Group III 15.92±5.7; p=0.5).

Figure 1

Conclusions

In ADHF, the association between RV to Pc uncoupling, echo-derived measures of congestion and natriuretic peptide levels is here described for the first time. The extent of RV dysfunction in ADHF deserves attention and seems to represent a critical and quite underestimated key mechanism between congestion resolution and in-hospital worsening HF.

Management of patients with recently implanted coronary stents on dual antiplatelet therapy who need to undergo major surgery

About 5% of patients undergoing coronary stenting need to undergo surgery within the next year. The risk of perioperative cardiac ischemic events, particularly stent thrombosis (ST), is high in these patients, because surgery has a prothrombotic effect and antiplatelet therapy is often withdrawn in order to avoid bleeding. The clinical and angiographic predictors of ST are well known, and the proximity to an acute coronary syndrome adds to the risk. The current guidelines recommend delaying non-urgent surgery for at least 6 weeks after the placement of a bare metal stent and for 6-12 months after the placement of a drug-eluting stent, when the risk of ST is reduced. However, in the absence of formal evidence, these recommendations provide little support with regard to managing urgent operations. When surgery cannot be postponed, stratifying the risk of surgical bleeding and cardiac ischemic events is crucial in order to manage perioperative antiplatelet therapy in individual cases. Dual antiplatelet therapy should not be withdrawn for minor surgery or most gastrointestinal endoscopic procedures. Aspirin can be safely continued perioperatively in the case of most major surgery, and provides coronary protection. In the case of interventions at high risk for both bleeding and ischemic events, when clopidogrel withdrawal is required in order to reduce perioperative bleeding, perioperative treatment with the short-acting intravenous glycoprotein IIb-IIIa inhibitor tirofiban is safe in terms of bleeding, and provides strong antithrombotic protection. Such surgical interventions should be performed at hospitals capable of performing an immediate percutaneous coronary intervention at any time in the case of acute myocardial ischemia.

Safety of sentinel node biopsy in pregnant patients with breast cancer

BACKGROUND

Lymphoscintigraphy (LS) and sentinel lymph node biopsy (SLNB) have typically been contraindicated for pregnant patients diagnosed with breast cancer because they are considered unsafe.

PATIENTS AND METHODS

Twenty-six premenopausal non-pregnant patients who were candidates for LS underwent peritumoral injection of approximately 12 MBq of 99mTc-HSA nanocolloids. Static [15 min and 16 h post-injection (p.i.)] and whole-body (16 h p.i.) scintigraphic images were acquired. Activity concentration in the urine (0-2, 2-4, 4-8, 8-16 h p.i.) was evaluated by a gamma-counter. Activity in the bloodstream was measured at 4 and 16 h p.i. Thermoluminescent dosimeters (TLD) were placed, before tracer injection, on the injection site, between injection site and epigastrium (two points), and on the epigastrium, umbilicus and hypogastrium, and were removed before surgery.

RESULTS

Scintigraphic images showed no radiotracer concentration except in the injection site and in the sentinel node. In all patients, the total activity excreted within the first 16 h was <2% of the injected activity. Activity in the blood pool was, at each time point, <1% of the injected activity. In 23 of 26 patients, all absorbed dose measurements were lower than the sensitivity of the TLD (<10 microGy); in the remaining three patients, the absorbed doses at the level of epigastrium, umbilicus and hypogastrium were in the following ranges: 40-320, 120-250 and 30-140 microGy, respectively.

CONCLUSIONS

According to our standard technique (12 MBq of 99mTc-HAS), LS and SLNB can be performed safely during pregnancy, since the very low prenatal doses from this diagnostic procedure, when properly performed, do not significantly increase the risk of prenatal death, malformation or mental impairment.

A novel Notch3 gene mutation not involving a cysteine residue in an Italian family with CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary cerebrovascular disease leading to accumulating neurologic deficits and dementia. CADASIL has been linked to nucleotide substitutions and deletions in the Notch3 gene. All the mutations described until now lead to unpaired cysteine residue in the epidermal growth factor-like repeats. The authors report a family with CADASIL carrying a deletion in the Notch3 gene that did not involve a cysteine residue.

Association of tau gene polymorphism with Parkinson's disease

We investigated the segregation of the dinucleotide GT repeat polymorphism in the intron between exons 9 and 10 of the tau gene in 300 patients with Parkinson's disease (PD) and in 197 normal controls. The A3 allele was more frequent in cases than in controls (30% versus 16%, p<0.001), and individuals carrying at least one A3 allele in their genotype had an increased risk of developing PD (odds ratio 2.78, 95% confidence interval 1.81-4.29). No significant differences were found between patients by considering the age at onset and the presence of family history or dementia. Our findings suggest a possible involvement of the tau gene in the pathogenesis of PD.

Body weight, levodopa pharmacokinetics and dyskinesia in Parkinson's disease

We conducted a pharmacokinetic study in 164 patients with sporadic Parkinson's disease (PD) to address the relationship between body weight and levodopa pharmacokinetics. Patients underwent an oral acute levodopa test with 250 mg levodopa and pharmacokinetic variables were further assessed. Plasmatic levodopa area under the curve (AUC-l) and body weight were significantly and inversely correlated. Women were significantly lighter and more dyskinetic than men, and had greater AUC-l values. Our data suggest that during long-term treatment, lighter PD patients, especially women, may receive a greater cumulative dosage of levodopa per kilogram of body weight. This could explain gender differences for the development of levodopa-induced peak-dose dyskinesias observed during the course of the disease.

Anti-GM1 ganglioside antibodies in Parkinson's disease

OBJECTIVES

To determine whether anti-GM1 antibodies are increased in Parkinson's disease (PD).

METHODS

Serum immunoglobulin M (IgM) and IgG anti-GM1 antibodies were detected by enzyme-linked immunosorbent assay (ELISA) in 147 patients with PD and in 186 age-matched normal control subjects. Sera were assayed at initial dilution of 1:800 for IgM and 1:200 for IgG and were considered positive at absorbance values exceeding the value of 0.05 for IgM and 0.1 for IgG.

RESULTS

Forty patients with PD (27.2%) had sera positive for IgM anti-GM1 antibodies, whereas only five normal controls (2.7%) resulted positive (P < 0.0001). Most of patients (75%) with positive sera had a tremor-dominant form of PD. Only two patients with PD (1.4%) and none of normal controls had sera positive for IgG anti-GM1 antibodies.

CONCLUSION

A consistent portion of parkinsonians, mainly with a tremor-dominant form of PD, may have increased circulating IgM anti-GM1 antibodies.

Plasma levels of vitamin E in Parkinson's disease

Oxidative stress has been implicated as a major contributor to selective neuronal death in Parkinson's disease (PD). Vitamin E is an antioxidant that may protect the brain from free radical-induced oxidative damage. It is, therefore, reasonable to hypothesize that low levels of vitamin E concentrations may increase the risk of developing PD. To elucidate the possible role of vitamin E in the pathogenesis of PD, we assessed the plasma levels of vitamin E, measured by high-performance liquid chromatography (HPLC), in 54 patients with PD. Vitamin E concentrations were also assessed in 93 age and sex matched normal individuals. The mean plasma levels of vitamin E did not differ significantly between these two groups (22.5+/-8.15 &mgr;mol/l for PD patients and 21.0+/-7.9 &mgr;mol/l for controls). The results of our study suggest that plasma vitamin E concentrations do not play a major role in the pathogenesis of PD.

The long-duration response to L-dopa in the treatment of early PD

OBJECTIVE

To investigate the long-duration response (LDR) to L-dopa resulting from different regimens of L-dopa.

BACKGROUND

In clinical practice, L-dopa is usually administered without considering the LDR due to the drug. Moreover, it has not been established whether in early PD a multiple daily intake of small doses of L-dopa may induce a sustained LDR.

METHODS

Twenty-four patients with early PD underwent a double-blind, crossover trial, comparing three different 15-day treatment periods with L-dopa: treatment A (250 mg every 24 hours); treatment B (250 mg every 8 hours); and treatment C (125 mg every 8 hours). After completion, 20 patients underwent a subsequent open-label randomized trial with prolonged treatments (250 mg every 24 hours or 125 mg every 8 hours) up to 3 months. LDR was measured at the end of each treatment.

RESULTS

All patients achieved a sustained LDR after treatments A and B, whereas only 17% of patients reached a sustained LDR after treatment C. Overall, the LDRs resulting from treatments A and B had similar magnitude and were larger than the LDR deriving from treatment C. After 3 months of prolonged treatments, only three of 10 patients treated with 125 mg every 8 hours increased their LDR, whereas all 10 patients treated with 250 mg every 24 hours had a maximal and stable LDR.

CONCLUSIONS

Sustained LDR to L-dopa is dependent on the amount of the single doses of the drug. A regimen scheduling small, divided doses during the day, as done in clinical practice, is a questionable therapy for the achievement of a sustained LDR.

The dopamine D2 receptor gene is a susceptibility locus for Parkinson's disease

The dopamine D2 receptor (DRD2) gene has been proposed as a candidate gene underlying several psychiatric and neurologic disorders. The aim of the present study was to examine if selected polymorphisms in the DRD2 gene are associated with Parkinson's disease (PD). We determined the allelic frequencies for four polymorphisms located in the DRD2 gene in a sample of 135 patients with PD and 202 normal control subjects. No significant difference was observed in the allelic frequencies between patients with PD and control subjects with regard to the -141C Ins/Del and the Ser311/Cys311 variants. On the contrary, the A1 allele of the TaqIA polymorphism and the B1 allele of the TaqIB polymorphism were more frequent in patients with PD than in control subjects (control subjects: TaqIA A1 = 14.6%, TaqIB B1 = 10.6%; patients with PD: TaqIA A1 = 20.7%, TaqIB B1 = 17.4%). Patients carrying the A1 allele or the B allele had an increased risk of developing PD (TaqIA, odds ratio: 1.71, 95% confidence intervals: 1.08-2.73; TaqIB, odds ratio: 1.83, 95% confidence intervals: 1.12-3.02). The TaqIA and TaqIB polymorphisms were in strong linkage disequilibrium, suggesting that these two polymorphisms convey the same information about the risk of presenting with PD. Genetic variation in the DRD2 gene may influence the risk of developing PD, thus confirming that the DRD2 gene is a susceptibility locus for PD.

Apolipoprotein E polymorphisms and Parkinson's disease

The apolipoprotein E (APOE) gene polymorphism has been studied in Parkinson's disease (PD) with conflicting results. Recently, a newly described functional polymorphism in the regulatory region of the APOE gene, (-491 A/T), has been associated with late-onset Alzheimer's disease. We studied the association between these two polymorphisms of the APOE gene with PD in a sample of 126 PD patients and in 119 controls from the same geographic background. Allelic and genotypic frequencies were not different between PD cases and population controls for either the APOE or -491 A/T polymorphism. The age at onset of the disease was not different according to the specific genotypes of the two polymorphisms of the APOE gene.

APOE and risk of cognitive impairment in multiple sclerosis

OBJECTIVES

The APOE gene polymorphism and the -491 A/T polymorphism in its regulatory region have been associated with an increased risk for developing Alzheimer's disease. We examined these polymorphisms in multiple sclerosis (MS) patients, to determine if a genetic predisposition may explain the risk for developing cognitive decline in MS.

MATERIAL AND METHODS

Eighty-nine relapsing-remitting and secondary progressive MS patients underwent to a full neuropsychological battery as well as to determination of APOE and -491 A/T polymorphisms. Genetic analysis was also performed in 107 population controls.

RESULTS

The APOE polymorphism was not associated with the risk of cognitive impairment in MS patients. The AA genotype of the -491 A/T polymorphism in the APOE regulatory region was more frequent in cognitively impaired than in cognitively preserved MS subjects.

CONCLUSION

The AA homozygous state of the -491 A/T polymorphism of the APOE regulatory region is associated with cognitive impairment in patients with MS.

GH secretion in thalassemia patients with short stature

The physiological role of GH secretion on growth retardation remains to be elucidated especially in patients with beta-thalassemia. In the present study, we investigated IGF-1 circulating levels as well as GH release following GHRH alone or combined with some inhibitors of somatostatin: pyridostigmine and arginine. In thalassemic patients lower IGF-1 circulating levels appear to be negatively correlated with both aspartate aminotransferase and alanine aminotransferase as well as with ferritin circulating levels indicating a probable role of hepatic hemosiderosis in IGF-1 production. The authors however suggest that reduced IGF-1 secretion is not the main cause of growth retardation since this would have elicited an enhanced response of GHRH in the presence of a normal hypothalamic pituitary axis. In contrast, they noticed that GH response to GHRH when expressed as area under the curve was lower in thalassemic patients compared to controls. The combination of GHRH with either pyridostigmine or arginine induced a GH secretion in thalassemics which was comparable to that of controls. The results of this study lead to conclude that the alteration of GH secretion is due, in such patients, to an increased somatostatin activity.

[Variations of blood bilirubin levels in the newborn with and without retinopathy of prematurity (ROP)]

Retinopathy of prematurity (ROP) is a multifactorial disease where production of free radicals is a pathogenic factor. Bilirubin is regarded today as the most powerful antioxidant substance "in vitro". To test such effect "in vivo" we studied 219 premature infants, admitted to our Neonatal Intensive Case Unit from April 1991 to October 1992, evaluating their serum bilirubin levels from day two to seven and mean bilirubin level of first week for each child. We also calculated the mean rate of daily increase of bilirubin. Our results show that bilirubin parameters considered are higher in neonates which will develop ROP of every stage than in the control ones. These results therefore do not support the concept that bilirubin could have a role in the prevention of ROP.

Skeletal changes in thalassemia major

The authors clinically and radiographically examined 72 patients with homozygous beta thalassemia. The clinical data were compared to the degree of osteoporosis calculated by Singh's method. The results indicate a high incidence of skeletal changes in patients with thalassemia, including lower limb-length discrepancy (16.6%), upper limb-length discrepancy (5.5%), axial deviation of the limbs (8.3%), osteochondrosis (2.7%), and osteopenia (25%). Based on their observations, the authors identify skeletal changes of adulthood (osteopenia) and childhood (limb-length discrepancy, axial deviation, osteochondrosis). The authors hypothesize that osteoporotic changes are caused principally by hyperplasia of the bone marrow, which widens the medullary space and increases intramedullary pressure, leading eventually to osteoporosis.