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Background Chronic active Epstein-Barr virus (EBV) infection (CAEBV) of the T-/NK-cell type, systemic form is a rare and potentially life-threatening illness caused by persistent EBV infection. The highest incidence is found in children and adolescents with increased frequency among Asians and Native Americans, while the disease is uncommon in Western countries. Typically patients present with unspecific symptoms, like fever, lymphadenopathy, hepatosplenomegaly and liver dysfunction. Due to fatal complications including hemophagocytic syndrome, coagulopathy, multiple organ failure and development of EBV-positive lymphoproliferative disease (LPD) or lymphoma early diagnosis is critical for successful treatment. However, in consequence of the lack of experience due to the low incidence in Europe, a broad spectrum of clinical manifestations and a particularly unexpected group of patients, diagnosis can be challenging. Inhere we describe the clinicopathological findings of an African adult with CAEBV associated LPD with a brief review of the literature. Case presentation A 42-year-old African man with fever, enlargement of the spleen and a suspected epileptic seizure was referred to our hospital. Diagnostic testing repeatedly revealed a massive EBV-DNA load in peripheral blood. Whole-body PET-CT-scan presented a strong uptake at multiple bone marrow sites, the thyroid and the adrenal glands. Histopathological analysis of bone marrow and thyroid gland revealed a highly proliferating, atypical and predominantly intravascular cytotoxic T-cell population with intracellular EBV-encoded RNA. Clonality analysis revealed the presence of polyclonal T-cell-receptor. Based on these findings a CAEBV of the T-/NK-cell type, systemic form was diagnosed. Subsequent therapy including three cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisolone resulted in decreased EBV load, clinical improvement and ongoing complete remission. Conclusion Adult-onset CAEBV of T/NK-cell type usually comprises a poor prognosis and is extremely rare in Western countries. Therefore, our case highlights the need for a clinical awareness of this disease in patients with systemic illness and for a comprehensive multidisciplinary diagnostic approach to facilitate diagnosis. Treatment options include antiviral drugs, immunosuppressive agents and systemic chemotherapy with or without allogeneic stem cell transplantation. Given the limited data these options need to be decided upon in each patient individually considering severity of the disease, comorbidities and response.

Gallium-68 is a generator-produced positron-emitting isotope. 68 Ga-labeled peptides are used for PET imaging. To prepare them, this protocol describes an efficient method for preconcentration and purification of 68 Ga. Gallium-68 ( 68 Ga) is a generator-produced radionuclide with a short half-life ( t ½ = 68 min) that is particularly well suited for molecular imaging by positron emission tomography (PET). Methods have been developed to synthesize 68 Ga-labeled imaging agents possessing certain drawbacks, such as longer synthesis time because of a required final purification step, the use of organic solvents or concentrated hydrochloric acid (HCl). In our manuscript, we provide a detailed protocol for the use of an advantageous sodium chloride (NaCl)-based method for radiolabeling of chelator-modified peptides for molecular imaging. By working in a lead-shielded hot-cell system, 68 Ga 3+ of the generator eluate is trapped on a cation exchanger cartridge (100 mg, ∼8 mm long and 5 mm diameter) and then eluted with acidified 5 M NaCl solution directly into a sodium acetate-buffered solution containing a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) or DOTA-like chelator-modified peptide. The main advantages of this procedure are the high efficiency and the absence of organic solvents. It can be applied to a variety of peptides, which are stable in 1 M NaCl solution at a pH value of 3–4 during reaction. After labeling, neutralization, sterile filtration and quality control (instant thin-layer chromatography (iTLC), HPLC and pH), the radiopharmaceutical can be directly administered to patients, without determination of organic solvents, which reduces the overall synthesis-to-release time. This procedure has been adapted easily to automated synthesis modules, which leads to a rapid preparation of 68 Ga radiopharmaceuticals (12–16 min).

PurposeDetermining the glomerular filtration rate (GFR) is essential for clinical medicine but also for pre-clinical animal studies. Functional imaging using positron emission tomography (PET) allows repetitive almost non-invasive measurements. The aim of the study was the development and evaluation of easily synthesizable PET tracers for GFR measurements in small animals.ProceduresDiethylenetriaminepentaacetic acid (DTPA) and ethylenediaminetetraacetic acid (EDTA) were labeled with Ga-68. The binding to blood cells and plasma proteins was tested in vitro. The distribution of the tracers in rats was analyzed by PET imaging and ex vivo measurements. From the time-activity-curve of the blood compartment (heart) and the total tracer mass excreted by the kidney, the GFR was calculated. These values were compared directly with the inulin clearance in the same animals.ResultsBoth tracers did not bind to blood cells. [68Ga]DPTA but not [68Ga]EDTA showed strong binding to plasma proteins. For this reason, [68Ga]DPTA stayed much longer in the blood and only 30 % of the injected dose was eliminated by the kidney within 60 min whereas the excretion of [68Ga]EDTA was 89 ± 1 %. The calculated GFR using [68Ga]EDTA was comparable to the measured inulin clearance in the same animal. Using [68Ga]-DPTA, the measurements led to values which were 80 % below the normal GFR. The results also revealed that definition of the volume of interest for the blood compartment affects the calculation and may lead to a slight overestimation of the GFR.Conclusions[68Ga]EDTA is a suitable tracer for GFR calculation from PET imaging in small animals. It is easy to be labeled, and the results are in good accordance with the inulin clearance. [68Ga]DTPA led to a marked underestimation of GFR due to its strong binding to plasma proteins and is therefore not an appropriate tracer for GFR measurements.

Gallium-68 is a generator-produced positron-emitting isotope. .sup.68Ga-labeled peptides are used for PET imaging. To prepare them, this protocol describes an efficient method for preconcentration and purification of .sup.68Ga.

Gallium-68 ((68)Ga) is a generator-produced radionuclide with a short half-life (t½ = 68 min) that is particularly well suited for molecular imaging by positron emission tomography (PET). Methods have been developed to synthesize (68)Ga-labeled imaging agents possessing certain drawbacks, such as longer synthesis time because of a required final purification step, the use of organic solvents or concentrated hydrochloric acid (HCl). In our manuscript, we provide a detailed protocol for the use of an advantageous sodium chloride (NaCl)-based method for radiolabeling of chelator-modified peptides for molecular imaging. By working in a lead-shielded hot-cell system,(68)Ga(3+) of the generator eluate is trapped on a cation exchanger cartridge (100 mg, ∼8 mm long and 5 mm diameter) and then eluted with acidified 5 M NaCl solution directly into a sodium acetate-buffered solution containing a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) or DOTA-like chelator-modified peptide. The main advantages of this procedure are the high efficiency and the absence of organic solvents. It can be applied to a variety of peptides, which are stable in 1 M NaCl solution at a pH value of 3-4 during reaction. After labeling, neutralization, sterile filtration and quality control (instant thin-layer chromatography (iTLC), HPLC and pH), the radiopharmaceutical can be directly administered to patients, without determination of organic solvents, which reduces the overall synthesis-to-release time. This procedure has been adapted easily to automated synthesis modules, which leads to a rapid preparation of (68)Ga radiopharmaceuticals (12-16 min).

PurposeThe enzyme O6-methylguanine-DNA methyltransferase (MGMT) is an important component of the DNA repair machinery. MGMT removes O6-methylguanine from the DNA by transferring the methyl group to a cysteine residue in its active site. Recently, we detected the single nucleotide polymorphism (SNP) rs12917 (C/T) in the MGMT sequence adjacent to the active site in Hodgkin lymphoma (HL) cell line KM-H2. We now investigated whether this SNP is also present in other HL cell lines and patient samples. Furthermore, we asked whether this SNP might have an impact on metabolic response in 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ([18F]FDG-PET), and on overall treatment outcome based on follow-up intervals of at least 34 months.ProceduresWe determined the frequency of this MGMT polymorphism in 5 HL cell lines and in 29 pediatric HL (PHL) patients. The patient cohort included 17 female and 12 male patients aged between 4 and 18 years. After characterization of the sequence, we tested a possible association between rs12917 and age, gender, Ann Arbor stage, treatment group, metabolic response following two courses of OEPA (vincristine, etoposide, prednisone, and doxorubicin) chemotherapy, radiotherapy indication, and relapse status.ResultsWe detected the minor T allele in four of five HL cell lines. 11/29 patients carried the minor T allele whereas 18/29 patients showed homozygosity for the major C allele. Interestingly, we observed significantly better metabolic response in PHL patients carrying the rs12917 C allele resulting in a lower frequency of radiotherapy indication.ConclusionMGMT polymorphism rs12917 seems to affect chemotherapy response in PHL. The prognostic value of this polymorphism should be investigated in a larger patient cohort.