Microglia control vascular architecture via a TGFβ1 dependent paracrine mechanism linked to tissue mechanics

Tissue microarchitecture and mechanics are important in development and pathologies of the Central Nervous System (CNS); however, their coordinating mechanisms are unclear. Here, we report that during colonization of the retina, microglia contacts the deep layer of high stiffness, which coincides with microglial bipolarization, reduction in TGFβ1 signaling and termination of vascular growth. Likewise, stiff substrates induce microglial bipolarization and diminish TGFβ1 expression in hydrogels. Both microglial bipolarization in vivo and the responses to stiff substrates in vitro require intracellular adaptor Kindlin3 but not microglial integrins. Lack of Kindlin3 causes high microglial contractility, dysregulation of ERK signaling, excessive TGFβ1 expression and abnormally-patterned vasculature with severe malformations in the area of photoreceptors. Both excessive TGFβ1 signaling and vascular defects caused by Kindlin3-deficient microglia are rescued by either microglial depletion or microglial knockout of TGFβ1 in vivo. This mechanism underlies an interplay between microglia, vascular patterning and tissue mechanics within the CNS.

Clinical Implications of a New TSH-receptor-antibody-assay (DYNOtest® TRAKhuman) in Autoimmune Thyroid Diseases

Aim: Conventional radioreceptor-antibody-assays (RAAs) fail in the detection of TSH-receptor antibodies (TRAKs) in 10–30% of patients with Graves’ disease (GD). The aim of this study was the evaluation of the diagnostic and clinical impact of a new RRA (DYNOtest® TRAKhuman) which uses the human recombinant TSH-Receptor in the diagnosis of autoimmune thyroid disease. Methods: Sera from 142 consecutive patients (GD: n=50, autoimmune thyroiditis/AIT: n=92) and from 55 controls (31 patients without any thyroid disease and 14 with euthyroid goiter) were evaluated both with the DYNOtest® TRAKhuman-assay and a conventional RRA (TRAK-Assay®). Thyroid in vitro parameters and thyroid sonography were performed in all patients. Results: The DYNOtest® TRAK-assay was significantly superior to the conventional RRA in the diagnosis of GD (p < 0,00012), especially in those who were treated by thionamides (p < 0,003) and in the diagnosis of TRAK-positive patients with AIT(p < 0,003). The majority of TRAK-positive AIT-patients suffered from hypothyroidism. One false positive result in patients with euthyroid goiter was found in the TRAK-Assay® as well as in the DYNOtest® TRAKhuman-Assay. Therefore the specifity of the DYNOtest® TRAKhuman was not inferior compared with the conventional assay. Conclusion: The DYNOtest® TRAK-assay is superior in the diagnostic work up of Graves’ disease compared with a conventional TRAK-assay and offeres an equal specifity.

Diagnostic 123I and 131I activities and radioiodine therapy

Aim: Urinary iodine excretion (UIE) provides information about iodine supply and release. In the present study we investigated effects of the application of different radioiodine isotopes on UIE in patients with differentiated thyroid carcinoma (DTC). Patients, methods: In 91 consecutive patients with DTC UIE, measured as iodine/creatinine ratio, was determined before and after application of 123I and 131I for diagnostic or therapeutic purposes. Additionally, remnant volume (V) was determined prior to therapy. Group A consisted of 33 patients with supposed successful ablation of DTC. These patients received 370 MBq 131I for diagnostic use and served as controls. 58 patients (group B) with remnants, relapses and metastases received 370 MBq 123I for diagnostics prior to therapy with 1.5-22.2 GBq 131I. Factors influencing individual changes in urinary iodine excretion (ΔUIE) were investigated by using non-parametric tests. Results: In group A UIE did not change significantly after application of 131I. As well, UIE remained unchanged after diagnostic application of 123I in group B. In contrast, UIE increased significantly already 24 h after therapeutic application of 131I in this group. In patients with small remnants (V < 2.5 ml) a significant but only moderate increase of UIE could be observed (average increase: 47 μg I/g crea). In patients with larger remnants, with relapses or metastases increase of UIE values was significant and more pronounced. Conclusions: It was confirmed that UIE increased significantly during radioiodine therapy in patients with DTC and radioiodine-accumulating tissue. The increase of UIE after therapeutic administration of radioiodine can be explained by the disintegrated thyroid follicles in thyroid remnants. The radioiodine-induced iodine release may be one reason for thyroid “stunning” even after application of diagnostic amounts of 131I.

Clinical evaluation of a new thyroglobulin immunoradiometric assay in the follow-up of differentiated thyroid carcinoma

Aim: Formal and clinical comparison of a new 3rd-gene-ration-Tg-IRMA (3-G-IRMA; Dynotest®Tg-plus) with a conventional Tg-IRMA (3-G-IRMA; SELco®Tg-assay) for patients with differentiated thyroid carcinoma. In addition we evaluated, if thyroglobulin (Tg) levels above a specific threshold concentration indicate the need for further investigations for residual disease. Patients, methods: Tg concentration of 105 sera of 93 consecutive patients with a differentiated thyroid cancer was determined with both assays and compared at different cut-off values (Dynotest®Tg-plus: 0.2, 1, 2 ng/ml; SELco®Tg-assay: 0.5, 1, 2 ng/ml) with the clinical results in respect to the corresponding TSH concentration. Results: Tg concentration did not show any significant difference (SELco®Tg-assay 0.5 ng/ml, Dynotest® Tg-plus 0.2 ng/ml). The Tg-values of both assays correlated with 97%. However, correlation of recovery in both assays was small (40%). The sensitivities and specificities of both assays at different cut-offs and TSH values did not reveal significant differences. In patients with TSH concentration >30 µU/ml the functional assay sensitivity was superior to arbitrary cut-offs in the decision to start further evaluations. Conclusions: In our study neither formal nor clinical significant differences between two Tg-assays were found. In a hypothyroid patient (TSH >30 µU/ml, Tg concentration exceeding the functional assay sensitivity) further investigations for residual disease are warranted. Higher thresholds are of limited value, due to a inacceptable high rate of false negative results.

Expression of the sodium iodide symporter in differentiated thyroid cancer

Aim: Molecular analysis of the expression of the sodium iodide symporter (NIS) in 32 patients with differentiated thyroid cancer (DTC) and correlation with scintigraphic findings (131I,123I) in 19 (59.4%) of them. Patients, methods: NIS expression of 27 primary tumours, 13 lymphnodes and 18 distant metastases was determined by immunostaining using a murine monoclonal anti-NIS-antibody. NIS expression and radionuclide uptake of metastases were analysed by a semiquantitative visual score. Patients were divided into two subgroups: Group 1 (n = 8 patients): indirect correlation of radioiodine uptake (RIU) of subsequent metastases with NIS expression of 7 primary tumours and 3 metastases; Group 2 (n=11 patients): direct correlation of radionuclide uptake with NIS expression of 19 metastases which were excised after imaging. Results: 49 of 58 specimens (84.5%) were NIS-positive. A preserved NIS-expression was found in 12 primary tumours and 8 of 10 (80%) synchrone and 6 of 7 (85.7%) metachrone metastases. Group 1 revealed a 100% positive predictive value (PPV) of a preserved NIS expression in the primary tumour regarding radioiodine uptake in metastases while a lack of NIS expression in the primary tumor did not reliable predict a loss of the metastases’ ability to concentrate radioiodine. In group 2, only 11 of 19 (57.9%) specimens showed a concordant NIS expression and RIU whereas in the remaining 8 cases without visible RIU NIS expression was still present. Conclusions: NIS expression of the primary tumour and metastases in DTC is usually well preserved. We found a positive correlation between NIS expression of the primary and metastatic tissue but could not identify such well correspondence between NIS expression and the RIU of subsequent metastases.

Improvement of tomographic reconstruction in bone SPECT

Aim: The comparison between iterative reconstruction and filtered backprojection in the reconstruction of bone SPECT in the diagnosis of skeletal metastases. Patients, methods: 47 consecutive patients (vertebral segments: n = 435), with suspected malignancy of the vertebral column, were examined by bone scintigraphy and MRI (maximal interval between the two procedures ± 5 weeks). The SPECT-data were reconstructed with an iterative algorithm (ISA) and with filtered backprojection. We defined semiquantitative criteria in order to assess the quality of the tomograms. Conventional reconstruction was performed both by a Wiener-filter and a low-pass-filter. Iterative reconstruction was performed by the ISA algorithm. The clinical evaluation of the different reconstruction algorithms was performed by MRI as the gold-standard. Results: Sensitivity (%): 87.3 (ISA), 86.4 (low-pass), 79.7 (Wiener); specificity (%): 95.3 (ISA), 95 (low-pass), 85.4 (Wiener). The sensitivity of iterative reconstructed SPECT and low-pass reconstructed SPECT was significantly higher (p <0.05) compared with the sensitivity of SPECT reconstructed by the Wiener-filter. The specificity of iterative reconstruction ISA and low-pass-filter reconstructed SPECT were significantly higher compared with the SPECT data reconstructed by the Wiener-filter. ISA was significantly superior to the Wiener- SPECT relating to all criteria of quality. Iterative reconstruction was significantly superior to the low-pass-SPECT relating to 2 of 3 criteria. In addition the Wiener-SPECT was significantly inferior to the low-pass-SPECT regarding to 2 of 3 criteria. Conclusion: In our series the iterative algorithm ISA was the method of choice in the reconstruction of bone SPECT data. In comparison with conventional algorithms ISA offers a significantly higher quality of the tomograms and yields a high diagnostic accuracy.

Quantitative thyroid scintigraphy for the differentiation of Graves’ disease and hyperthyroid autoimmune thyroiditis

Aim: The TCTUs (global 99mTc-pertechnetate thyroid uptake under suppression) can be used as an estimate of the iodine clearance of non-TSH regulated tissue. High TCTUs levels are characteristic for Graves’ disease (GD). Decreased uptake has been described in autoimmune thyroiditis (AIT). However, systematically investigated data in a larger series of AIT-patients with subclinical or overt hyperthyroidism are not published so far. The purpose of this study is the evaluation of the TCTUs in the differentiation between AIT and GD in patients with hyperthyroidism. Methods: We determined the TCTUs in 59 patients with untreated hyperthyroid GD and in 51 patients with AIT who had subclinical or manifest hyperthyroidism without medication. Patients with GD were characterized by the presence of hyperthyroidism, decreased echogenicity of the thyroid, elevation of TSH-receptor autoantibodies (TRAb). AIT was defined by a decreased echogenicity of the thyroid, absence of elevated TSH-receptor autoantibodies (TRAb), autoantibodies against the thyroid peroxidase (anti-TPO) and spontaneous remission or development of subclinical hypothyroidism within 3 months. Results: Thyroid volumes of patients with AIT were significantly lower than those of patients with GD (p <0.05). TRAb levels were significantly higher in GD-patients (median: 19.5 U/ml; range: 15.3-35 U/ml) than in AIT-patients (median: 1.3 U/ml; range: 0-4.1 U/ml). 73% (38/59) of patients with GD had elevated anti-TPO levels. In these patients anti-TPO levels (median: 768 U/l; range: 83-6397 U/l) were not significantly different from anti-TPO levels of patients with AIT (median: 834 U/l; range: 107-8675 U/l; p = 0.17). TCTUs values of patients with AIT were significantly lower (p <0.05; median: 0.9%; range: 0.1-3.2%) than those of patients with GD (median: 5.7%; range: 1.9-28.3%). Conclusion: In our patients quantitative thyroid scintigraphy with 99mTcO4 - offered rapid and reliable differentiation between hyperthyroid GD and AIT.

F-18-FDG-hybrid-camera-PET in patients with postoperative fever

Aim: Evaluation of F-18-FDG-hybrid-camera-PET imaging in patients with undetermined postoperative fever (POF). Methods: Prospective study of 18 patients (9 women, 9 men; age 23-85 years) suffering from POF with 2-fluoro-2’-deoxyglucose (F-18-FDG) using a dual headed coincidence camera (DHCC). Surgery had been performed 5-94 days prior to our investigation. 13 of the 18 patients received antibiotic therapy during the time of evaluation. Ten (55%) had an infectious and eight (45%) a non infectious cause of fever. Results: Increased F-18-FDG-uptake outside the surgical wound occurred in 13 regions (infection n = 11, malignancy n = 2). The sensitivity of F-18-FDG-hybrid-camera-PET in imaging infection in areas outside the surgical wound was 86% and the specificity 100%, respectively. Antibiotic therapy did not negatively influence the results of F-18-FDG-scanning. Increased F-18-FDG-uptake within the surgical wound was seen in 8 of 18 patients. The sensitivity of F-18-FDG-hybrid-camera-PET in imaging infection within the surgical wound was 100% and the specificity 56%, respectively. The interval between surgery and F-18-FDG-scanning was significantly shorter in patients with false positive results compared with patients showing true negative results (median 34 vs. 54 days; p = 0,038). Conclusion: In POF-Patients, F-18-FDG transaxial tomography performed with a F-18-FDG-hybrid-camera-PET is sensitive in the diagnosis of inflammation and malignant disease within and outside the surgical wound. Because of the accumulation of the tracer both in granulation tissue and infection, the specificity in detecting the focus of fever within the surgical wound is poor.

How reliable is secondary risk stratification with stimulated thyroglobulin in patients with differentiated thyroid carcinoma?

Objective: Primary risk factors in patients with differentiated thyroid carcinoma (DTC) are well established. In our institution, secondary risk stratification has been performed with stimulated Thyroglobulin (sTg; TSH > 30 mIU/l) within six months after primary therapy since 2001. In this study, we evaluated the predictive value of sTg for long-term disease- free survival (DFS). Patients, methods: Data of 202 consecutive patients with DTC were analyzed retrospectively. Median follow-up time was 6.4 years (12 months to 16.2 years). Patients were staged according to Union International Contre le Cancer (UICC) criteria. Primary risk stratification was carried out according to European Thyroid Association criteria. Initially, 134 patients (66%) were classified as low-risk and 68 patients (34%) as high-risk. The influence of established risk factors and sTg on DFS was analyzed at three different time points, up to 36 months after initial therapy. Results: In total, 169 (84%) of all patients remained in complete remission after surgery followed by radioiodine-therapy. Six patients (3%) developed tumour recurrence after initial complete remission. Primary risk factors for persistent disease were male sex, follicular or oncocytic tumour, primary tumour > 4 cm in diameter, initial lymph node involvement, initial metastatic disease and microscopic or macroscopic residual tumor. sTg ≤ 0.3 ng/ml measured within six months after initial therapy was a highly significant predictor (p ≤ 0.001) for lasting DFS, 99% of patients with sTg ≤ 0.3 ng/ml were in complete remission 36 months after initial therapy. Conclusions: A stimulated Tg ≤ 0.3 ng/ml within six months after initial therapy is a reliable predictor for long-term disease- free survival independent of primary risk stratification.

Integrin-Kindlin3 requirements for microglial motility in vivo are distinct from those for macrophages

Microglia play a critical role in the development and homeostasis of the CNS. While mobilization of microglia is critical for a number of pathologies, understanding of the mechanisms of their migration in vivo is limited and often based on similarities to macrophages. Kindlin3 deficiency as well as Kindlin3 mutations of integrin-binding sites abolish both integrin inside-out and outside-in signaling in microglia, thereby resulting in severe deficiencies in cell adhesion, polarization, and migration in vitro, which are similar to the defects observed in macrophages. In contrast, while Kindlin3 mutations impaired macrophage mobilization in vivo, they had no effect either on the population of microglia in the CNS during development or on mobilization of microglia and subsequent microgliosis in a model of multiple sclerosis. At the same time, acute microglial response to laser-induced injury was impaired by the lack of Kindlin3-integrin interactions. Based on 2-photon imaging of microglia in the brain, Kindlin3 is required for elongation of microglial processes toward the injury site and formation of phagosomes in response to brain injury. Thus, while Kindlin3 deficiency in human subjects is not expected to diminish the presence of microglia within CNS, it might delay the recovery process after injury, thereby exacerbating its complications.

ABCC3 genetic variants are associated with postoperative morphine-induced respiratory depression and morphine pharmacokinetics in children

Respiratory depression (RD) is a serious side effect of morphine and detrimental to effective analgesia. We reported that variants of the ATP binding cassette gene ABCC3 (facilitates hepatic morphine metabolite efflux) affect morphine metabolite clearance. In this study of 316 children undergoing tonsillectomy, we found significant association between ABCC3 variants and RD leading to prolonged postoperative care unit stay (prolonged RD). Allele A at rs4148412 and allele G at rs729923 caused a 2.36 (95% CI=1.28-4.37, P=0.0061) and 3.7 (95% CI 1.47-9.09, P=0.0050) times increase in odds of prolonged RD, respectively. These clinical associations were supported by increased formation clearance of morphine glucuronides in children with rs4148412 AA and rs4973665 CC genotypes in this cohort, as well as an independent spine surgical cohort of 67 adolescents. This is the first study to report association of ABCC3 variants with opioid-related RD, and morphine metabolite formation (in two independent surgical cohorts).

Pelvic lymph node dissection for nodal oligometastatic prostate cancer detected by 68Ga-PSMA-positron emission tomography/computerized tomography

BACKGROUND

The first evaluation of pelvic extended lymph node dissection (pLND) in oligometastatic prostate cancer (PCa) detected by (68)Ga-PSMA PET/CT.

METHODS

Retrospective analysis of 35 PCa patients underwent (68)Ga-PSMA PET/CT affected by biochemical recurrence (BCR) after curative treatment (n = 23) or before primary therapy of high-risk PCa (n = 12). We performed pLND associated with pathologic imaging in 17 men with nodal oligometastatic PCa.

RESULTS

Indicative lesions for PCa in PET/CT were detected in 91.4% (32 of 35) of patients. Nodal, bone, visceral (pulmonary), and within the prostate suspected disease were detected in 72% (23 of 32), 16% (5 of 32), 6% (2 of 32), and 47% (15 of 32) of patients, respectively. Median serum PSA in patients with pathological radiotracer uptake in recurrent and high-risk PCa patients was 2.9 ng/ml (range 0.18-30) and 19.5 ng/ml (range 6-90), respectively. The median number of removed lymph nodes with pLND in recurrent and high-risk PCa was 10 (range 4-17) and 12 (range 8-29) per patient and the median number of positive lymph nodes was 1 (range 1-2) and 3 (2-3) per patient, respectively. In total, two false positive and one false-negative lymph node were found. Diagnostic accuracies per nodal lesion in total of 213 removed nodes: sensitivity, 94%; specificity, 99%; positive predictive value (PPV), 89%, and negative predictive value (NPV), 99.5%. After pLND, 53% (9 of 17) of patients received androgen deprivation therapy and/or radiation therapy and hormonal therapy, while 47% (8 of 17) of patients remained free of any post-surgery therapy. Follow-up PSA remained less than 0.2 ng/ml in 82% (14 of 17) of patients. After pLND, immediate BCR (PSA never measured less than 0.2 ng/ml) in 18% (3 of 17) of patients was recorded.

CONCLUSIONS

This represents the first study of pLND in the setting of nodal oligometastatic PCa detected by (68)Ga-PSMA PET/CT. The use of (68)Ga-PSMA PET/CT could be to improve the accuracy for the detection of nodal micrometastases. These promising findings need validation in larger studies.

Emergence and subsequent functional specialization of kindlins during evolution of cell adhesiveness

Kindlins are integrin-interacting proteins essential for integrin-mediated cell adhesiveness. In this study, we focused on the evolutionary origin and functional specialization of kindlins as a part of the evolutionary adaptation of cell adhesive machinery. Database searches revealed that many members of the integrin machinery (including talin and integrins) existed before kindlin emergence in evolution. Among the analyzed species, all metazoan lineages—but none of the premetazoans—had at least one kindlin-encoding gene, whereas talin was present in several premetazoan lineages. Kindlin appears to originate from a duplication of the sequence encoding the N-terminal fragment of talin (the talin head domain) with a subsequent insertion of the PH domain of separate origin. Sequence analysis identified a member of the actin filament-associated protein 1 (AFAP1) superfamily as the most likely origin of the kindlin PH domain. The functional divergence between kindlin paralogues was assessed using the sequence swap (chimera) approach. Comparison of kindlin 2 (K2)/kindlin 3 (K3) chimeras revealed that the F2 subdomain, in particular its C-terminal part, is crucial for the differential functional properties of K2 and K3. The presence of this segment enables K2 but not K3 to localize to focal adhesions. Sequence analysis of the C-terminal part of the F2 subdomain of K3 suggests that insertion of a variable glycine-rich sequence in vertebrates contributed to the loss of constitutive K3 targeting to focal adhesions. Thus emergence and subsequent functional specialization of kindlins allowed multicellular organisms to develop additional tissue-specific adaptations of cell adhesiveness.

Late manifestation of subclinical hyperthyroidism after goitrogenesis in an index patient with a N670S TSH receptor germline mutation masquerading as TSH receptor antibody negative Graves' disease

In 27 families with familial non-autoimmune hyperthyroidism (FNAH) reported up to date, the onset of hyperthyroidism varies from 18 months to 60 years. Also the manifestation of goitres is variable in these families. A 74-year-old woman first presented at the age of 69 years with tachyarrhythmia and hypertension. After initial treatment of her hypertension and oral anticoagulation for her intermittent atrial fibrillation, a thyroid workup revealed a suppressed TSH and normal fT3 and fT4. TPO, TSH receptor (TSHR), and thyroglobulin antibodies were negative. Thyroid ultrasound revealed a thyroid volume of 102 ml with several nodules with diameters of up to 2.6 cm right and up to 1.8 cm left. Scintigraphy showed a homogeneous Technetium-99 m ((99 m)Tc) uptake of 1.27%. She was subsequently treated with 1 GBq radioiodine ((131)I). At the age of 74, her thyroid function was normal and her thyroid volume decreased to 90 ml. Because of the diffuse (99 m)Tc uptake and the negative TPO, TSHR, and thyroglobulin antibodies, genetic analysis of her TSHR gene was performed, in spite of her negative family history for hyperthyroidism. Sequencing revealed a N670S TSHR germline mutation. Previous in vitro characterisation of this TSHR mutation suggests a weak constitutive activity, yet the experimental data are ambiguous. This case illustrates the necessity to analyse patients with hyperthyroidism accompanied by diffuse (99 m)Tc uptake and negative TPO, TSHR, and thyroglobulin antibodies for TSHR germline mutations. Moreover, it demonstrates that TSHR germline mutations may first lead to longstanding nodular goitrogenesis before the late manifestation of subclinical hyperthyroidism.

Regulation of cell adhesion and migration by Kindlin-3 cleavage by calpain

Integrin activation on hematopoietic cells is essential for platelet aggregation, leukocyte adhesion, and transmigration through endothelium and extracellular matrix into inflamed tissues. To migrate through matrix, leukocyte integrin adhesion complexes undergo dynamic changes. Here we show that Kindlin-3, a main activator and binding partner of integrins in hematopoietic cells, can be cleaved by calpain in an activation-dependent manner. This calpain-mediated cleavage occurs in platelets and leukocytes as well as in endothelial cells. We determined the calpain I cleavage site in Kindlin-3 at tyrosine 373 in the N-terminal part of Kindlin-3 pleckstrin homology domain. Expression of the calpain-resistant Y373N mutant of Kindlin-3 promotes stronger cell adhesion to extracellular matrix under flow as well as to activated endothelium. In contrast, Y373N mutation in Kindlin-3 hinders cell migration. Mechanistically, calpain-resistant Y373N mutant of Kindlin-3 exhibited an activation-independent association with β integrin cytoplasm domain. Thus, cleavage of Kindlin-3 by calpain controls the dynamics of integrin-Kindlin-3 interaction and as a result, integrin-dependent adhesion and migration of hematopoietic cells. This represents a novel mechanism regulating reversibility of integrin adhesion complexes in leukocytes, which, in turn, is critical for their successful transmigration through the extracellular matrix.

Patients with autoimmune thyroiditis. Prevalence of benign lymphadenopathy

The prevalence of cervical lymphadenopathy in autoimmune thyroiditis (AIT) patients is actually unknown. The aim of the study was the detailed retrospective evaluation of 6 index-patients with lymphadenopathy in Robbins level VI and a prospective study with high resolution ultrasound of lymphadenopathy in AIT patients compared with controls in all compartments of the neck, accessible to sonographic evaluation.

PATIENTS, METHODS

The retrospective study comprises six patients with AIT, evaluated for enlarged Robbins level VI-LN. We report the findings of fine-needle aspiration Cytology, clonal analysis, histology, and serological testing. The prospective study evaluated the prevalence of lymphadenopathy in 49 consecutive patients with AIT (group 1) and 49 consecutive patients with normal thyroids or nontoxic goiter (group 2).

RESULTS

In the retrospective study, cytology of paratracheal LN revealed reactive lymphoid hyperplasia in 5/6 of the cases and a centroblastic lymphoma in one patient. The presence of monoclonal lymphatic cells was excluded in 5/6 patients and proven in 1/6 patients. Actual viral-infections were ruled out. In the prospective study AIT-patients showed significantly more enlarged LN in Robbins level II-IV and VI compared to controls. We found no correlation between lymphadenopathy, age, thyroid volume and nodularity, or autoantibody levels. During follow-up in 34 group 1-patients, lymphadenopathy remained stable in 28 patients, and decreased in 6 patients.

CONCLUSION

Lymphadenopathy in Robbins level II-IV and VI is common in AIT-patients and most probably related to the autoimmune process.

Novel aspects of Kindlin-3 function in humans based on a new case of leukocyte adhesion deficiency III

BACKGROUND

Kindlin-3 is a novel integrin activator in hematopoietic cells, and its deficiency leads to immune problems and severe bleeding, known as leukocyte adhesion deficiency III (LAD-III). Our current understanding of Kindlin-3 function primarily relies on analysis of animal models or cell lines.

OBJECTIVES

To understand the functions of Kindlin-3 in human primary blood cells.

PATIENTS/METHODS

We analyzed primary and immortalized hematopoietic cells obtained from a new LAD-III patient with immune problems, bleeding, a history of anemia, and abnormally shaped red blood cells.

RESULTS

The patient's white blood cells (WBCs) and platelets showed defects in agonist-induced integrin activation and botrocetin-induced platelet agglutination. Primary leukocytes from this patient exhibited abnormal activation of β(1) integrin. Integrin activation defects were responsible for the observed deficiency in the botrocetin-induced platelet response. Analysis of patient genomic DNA revealed a novel mutation in the Kindlin3 gene. The mutation abolished Kindlin-3 expression in primary WBCs and platelets, owing to abnormal splicing. Kindlin-3 is expressed in red blood cells (RBCs), and its deficiency is proposed to lead to abnormally shaped RBCs. Immortalized patient WBCs expressed a truncated form of Kindlin-3 that was not sufficient to support integrin activation. Expression of Kindlin-3 cDNA in immortalized patient WBCs rescued integrin activation defects, whereas overexpression of the truncated form did not.

CONCLUSIONS

Kindlin-3 deficiency impairs integrin function, including activation of β(1) integrin. Abnormalities in glycoprotein Ib-IX function in Kindlin-3-deficient platelets are secondary to integrin defects. The region of Kindlin-3 encoded by exon 11 is crucial for its ability to activate integrins in humans.

Integrin β3 crosstalk with VEGFR accommodating tyrosine phosphorylation as a regulatory switch

Integrins mediate cell adhesion, migration, and survival by connecting intracellular machinery with the surrounding extracellular matrix. Previous studies demonstrated the importance of the interaction between β₃ integrin and VEGF type 2 receptor (VEGFR2) in VEGF-induced angiogenesis. Here we present in vitro evidence of the direct association between the cytoplasmic tails (CTs) of β₃ and VEGFR2. Specifically, the membrane-proximal motif around ⁸⁰¹YLSI in VEGFR2 mediates its binding to non-phosphorylated β₃CT, accommodating an α-helical turn in integrin bound conformation. We also show that Y⁷⁴⁷ phosphorylation of β₃ enhances the above interaction. To demonstrate the importance of β₃ phosphorylation in endothelial cell functions, we synthesized β₃CT-mimicking Y⁷⁴⁷ phosphorylated and unphosphorylated membrane permeable peptides. We show that a peptide containing phospho-Y⁷⁴⁷ but not F⁷⁴⁷ significantly inhibits VEGF-induced signaling and angiogenesis. Moreover, phospho-Y⁷⁴⁷ peptide exhibits inhibitory effect only in WT but not in β₃ integrin knock-out or β₃ integrin knock-in cells expressing β₃ with two tyrosines substituted for phenylalanines, demonstrating its specificity. Importantly, these peptides have no effect on fibroblast growth factor receptor signaling. Collectively these data provide novel mechanistic insights into phosphorylation dependent cross-talk between integrin and VEGFR2.

Bilobar spreading of colorectal liver metastases does not significantly affect survival after R0 resection in the era of interdisciplinary multimodal treatment

PURPOSE

Bilobar colorectal liver metastases (CRLM) are often considered incurable or associated with poor prognosis even after R0 resection. In this single-center study, we evaluate the impact of CRLM spreading on recurrence-free survival (RFS) and cancer-specific overall survival (CSS) after R0 resection of CRLM with respect to multimodal treatment strategies including perioperative chemotherapy and multistep resections.

METHODS

Between January 2001 and December 2010, R0 resection could be achieved in 70 patients with bilobar and 100 with unilobar CRLM. Extent of disease, perioperative chemotherapy, surgical procedures, adjuvant treatment, histopathological workup, RFS, and CSS were compared between both cohorts.

RESULTS

Forty-six (66 %) patients with bilobar and 26 (26 %) patients with unilobar CRLM received preoperative chemotherapy (p < 0.001). For bilobar CRLM, more extended and multistep resection including portal vein occlusion were performed (29 % versus 3 %; p < 0.001). Morbidity (39 % versus 28 %, p = 0.183) and mortality (1 % versus 3 %, p = 0.644) rates were comparable in both patients' cohorts. Postoperative therapy was applied in adjuvant intent to 42 (60 %) versus 51 (51 %) patients (p = 0.275). The 5-year RFS and CSS rates were 24 % versus 31 % (p = 0.169) and 42 % versus 55 % (p = 0.131), respectively.

CONCLUSIONS

To our single-center experience, there is no significant effect of CRLM spreading (bilobar versus unilobar) on RFS and CSS rates. Bilobar CRLM are more likely to require extended multimodal efforts to achieve R0 resection.

68Ga-markierte Peptide für klinische Studien

The AMG implies far-reaching implications for the synthesis of new radiopharmaceuticals for clinical trials. Aim, methods: As a part of the DFG-funded Clinical Research Group (KFO 179) a project designated „Immuno-PET for assessment of early response to radiochemotherapy of advanced rectal cancer“ was initiated. This trial is focused on a trivalent bispecific humanized monoclonal antibody, and a 68Ga-labeled peptide. Following the new regulatory framework we established a GMPcompliant cleanroom laboratory and applied for a manufacturing permission. Results: During the project constructural, personnel and organizational conditions for a successful application were established, including a quality management system. A GMP-conform cleanroom laboratory class C was constructed, equipped with a two-chamber lock. The actual manufacturing is performed in a closed system with subsequent sterile filtration. The manufacturing processes have been automatised and validated as well as the necessary quality controls. The manufacturing permission was granted after an official inspection. Conclusions: The new German Drug Act is considered as a break in the production practice of nuclear medicine. The early involvement and communication with the authorities avoids time-consuming and costly planning errors. It is much to be hoped that the new legal situation in Germany will not cause serious impairments in the realization of clinical trials in German nuclear medicine.

Hemodynamic activation of beta-catenin and T-cell-specific transcription factor signaling in vascular endothelium regulates fibronectin expression

OBJECTIVE

The goal of this study was to assess the activity of β-catenin/T-cell-specific transcription factor (TCF) signaling in atherosclerosis development and its regulation of fibronectin in vascular endothelium.

METHODS AND RESULTS

Histological staining identified preferential nuclear localization of β-catenin in the endothelium of atheroprone aorta before and during lesion development. Transgenic reporter studies revealed that increased levels of TCF transcriptional activity in endothelium correlated anatomically with β-catenin nuclear localization and fibronectin deposition. Exposure of endothelial cells to human-derived atheroprone shear stress induced nuclear localization of β-catenin, transcriptional activation of TCF, and expression of fibronectin. Activation of fibronectin expression required β-catenin, TCF, and the transcriptional coactivator CRBP-binding protein. Finally, we identified platelet endothelial cell adhesion molecule-1 as a critical regulator of constitutive β-catenin and glycogen synthase kinase-3β activities.

CONCLUSIONS

These data reveal novel constitutive activation of the endothelial β-catenin/TCF signaling pathway in atherosclerosis and regulation of fibronectin through hemodynamic shear stress.

Targeting NCA-95 and other granulocyte antigens and receptors with radiolabeled monoclonal antibodies (Mabs)

During the last decade considerable effort has been made in the research for in vivo techniques of labeling neutrophils with peptides, labeled cytokines and (99m)Tc-labeled antigranulocyte monoclonal antibodies (AG-Mabs). In general the advantage of in vivo labeling is the simplicity of this approach compared with in vivo techniques. Three of these AG-Mabs have been evaluated in clinical studies: Besilesomab (Scintimun®), Sulesomab (Leucoscan®) and Fanolesomab (Leu-Tech®). White blood cells (WBCs) radiolabeled with AG-Mabs do not show the same behaviour as in vivo labeled white blood cells. Especially (99m)Tc-Sulesomab and (99m)Tc-Besilesomab image infectious foci mainly by non-specific extravasation with secondary binding to postmigratory leukocytes already present at the site of infection.

Suppression of RhoG activity is mediated by a syndecan 4-synectin-RhoGDI1 complex and is reversed by PKCalpha in a Rac1 activation pathway

Fibroblast growth factor 2 (FGF2) is a major regulator of developmental, pathological, and therapeutic angiogenesis. Its activity is partially mediated by binding to syndecan 4 (S4), a proteoglycan receptor. Angiogenesis requires polarized activation of the small guanosine triphosphatase Rac1, which involves localized dissociation from RhoGDI1 and association with the plasma membrane. Previous work has shown that genetic deletion of S4 or its adapter, synectin, leads to depolarized Rac activation, decreased endothelial migration, and other physiological defects. In this study, we show that Rac1 activation downstream of S4 is mediated by the RhoG activation pathway. RhoG is maintained in an inactive state by RhoGDI1, which is found in a ternary complex with synectin and S4. Binding of S4 to synectin increases the latter's binding to RhoGDI1, which in turn enhances RhoGDI1's affinity for RhoG. S4 clustering activates PKCalpha, which phosphorylates RhoGDI1 at Ser(96). This phosphorylation triggers release of RhoG, leading to polarized activation of Rac1. Thus, FGF2-induced Rac1 activation depends on the suppression of RhoG by a previously uncharacterized ternary S4-synectin-RhoGDI1 protein complex and activation via PKCalpha.

FDG-PET in patients with fever of unknown origin: the importance of diagnosing large vessel vasculitis

This review analyzes the impact of 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) in the diagnostic work-up of classic fever of unknown origin (FUO) according to the criteria first proposed by Petersorf in 1961 and later modified by Durack et al. in 1991. Algorithms currently used in this diagnostic process are not strictly evidence based up to now. FDG accumulates in malignant tissues, but also in inflammatory cells by the overexpression of facultative glucose transporter-isotypes (mainly GLUT-1 and GLUT-3) and by an overproduction of glycolytic enzymes. Therefore, this technique covers a broad spectrum of possible etiologies for FUO. Once imaged, these lesions can be further investigated by other (e.g. invasive) and more specific methods. Until now, four prospective studies using FDG-PET in patients with classic FUO, encompassing 167 patients in total are published. Three retrospective studies with 125 patients are also available. These studies are discussed and weighted according to the control of selection-bias that was performed. An interstudy-bias may also be present resulting from a considerable variability in causes of FUO. A low number of diagnostic scans in a study may sometimes be related to a high rate of fevers caused by miscellaneous disorders or to a high rate of undiagnosed patients. In these disease categories, focal pathologies that can be imaged with FDG-PET, are rare. A high number of diagnostic scans is always related to a high prevalence of patients with medium- and large-vessel vasculitis. Available data indicate that FDG-PET has the potential to play an important role as a second line procedure in the management of about 1/3 of patients with classic FUO. It is expected that hybrid imaging (PET/computed tomography [CT]; PET/magnetic resonance imaging [MRI]) will improve the diagnostic impact of FDG-PET further, but prospective data about the value of this methods are currently not available. The question as to how these new techniques can be implemented into an evidence based diagnostic algorithm, can only be resolved within a multidisciplinary setting, avoiding both selection- and interstudy-bias whenever possible.

Two-stage hepatectomy (R0) with portal vein ligation--towards curing patients with extended bilobular colorectal liver metastases

BACKGROUND AND AIMS

Patients with bilobular colorectal liver metastases (CRLM) experience poor prognosis, especially when curative resection cannot be achieved. However, resectability in these patients is often limited by low future remnant liver volume (FRLV). The latter can be enhanced by a two-stage liver resection, using portal vein ligation to induce liver hypertrophy. The aim of this prospective pilot study was to evaluate safety, secondary resectability, and time to recurrence of two-stage hepatectomy with portal vein ligation (PVL) and complete surgical clearance of the FRLV in patients with bilobular CRLM.

MATERIALS AND METHODS

Out of 24 patients (63+/-8.26 years) with extended bilobular CRLM (metachronous n=10, synchronous n=14), 18 received preoperative 5-FU-based chemotherapy combined with oxaliplatin or irinotecan. Staging included thoracoabdominal computed tomography and (18)F-fluorodeoxyglucose-positron emission tomography scans. First-stage procedure consisted of PVL, resection of all CRLM in the FRLV, and radiofrequency ablation (RFA) of CRLM situated near the future resection plane.

RESULTS

During first-stage procedure, 7x RFA, 4x non-anatomical resections, and 4x bisegmentectomies were performed additionally to PVL. FRLV/body-weight ratio increased from 0.4% to 0.6% within 55 days (median) after PVL. Second-stage hepatectomy was performed in 19 patients without tumor progression. R0 resection was possible in 14 patients. During a median follow-up of 17 months, intrahepatic recurrence occurred in two, and extrahepatic recurrence in nine out of 14 patients.

CONCLUSION

Two-stage hepatectomy with PVL and complete surgical clearance of FRLV is safe even after intensified systemic chemotherapy resulting in a curative resection rate of 58.3% (73.7% of re-explored cases).

Endogenous RhoG is dispensable for integrin-mediated cell spreading but contributes to Rac-independent migration

Rac activation by integrins is essential for cell spreading, migration, growth and survival. Based mainly on overexpression of dominant-negative mutants, RhoG has been proposed to mediate integrin-dependent Rac activation upstream of ELMO and Dock180. RhoG-knockout mice, however, display no significant developmental or functional abnormalities. To clarify the role of RhoG in integrin-mediated signaling, we developed a RhoG-specific antibody, which, together with shRNA-mediated knockdown, allowed analysis of the endogenous protein. Despite dramatic effects of dominant-negative constructs, nearly complete RhoG depletion did not substantially inhibit cell adhesion, spreading, migration or Rac activation. Additionally, RhoG was not detectably activated by adhesion to fibronectin. Using Rac1(-/-) cells, we found that constitutively active RhoG induced membrane ruffling via both Rac-dependent and -independent pathways. Additionally, endogenous RhoG was important for Rac-independent cell migration. However, RhoG did not significantly contribute to cell spreading even in these cells. These data therefore clarify the role of RhoG in integrin signaling and cell motility.

RhoG regulates endothelial apical cup assembly downstream from ICAM1 engagement and is involved in leukocyte trans-endothelial migration

During trans-endothelial migration (TEM), leukocytes use adhesion receptors such as intercellular adhesion molecule-1 (ICAM1) to adhere to the endothelium. In response to this interaction, the endothelium throws up dynamic membrane protrusions, forming a cup that partially surrounds the adherent leukocyte. Little is known about the signaling pathways that regulate cup formation. In this study, we show that RhoG is activated downstream from ICAM1 engagement. This activation requires the intracellular domain of ICAM1. ICAM1 colocalizes with RhoG and binds to the RhoG-specific SH3-containing guanine-nucleotide exchange factor (SGEF). The SH3 domain of SGEF mediates this interaction. Depletion of endothelial RhoG by small interfering RNA does not affect leukocyte adhesion but decreases cup formation and inhibits leukocyte TEM. Silencing SGEF also results in a substantial reduction in RhoG activity, cup formation, and TEM. Together, these results identify a new signaling pathway involving RhoG and its exchange factor SGEF downstream from ICAM1 that is critical for leukocyte TEM.

Safety and efficacy of repeated anti-CEA radioimmunotherapy (RAIT) with 131I-labetuzumab post salvage resection of colorectal liver metastases

14507

Background: As shown recently (JCO 2005; 23:6763–70), a single application of RAIT improved both, median overall survival (OS), and 5-year survival rates of colorectal cancer (CRC) patients (pts) post salvage resection of liver metastases (LM) compared to controls without RAIT (P=0.004). In an ongoing phase II trial we are evaluating the safety and efficacy of repeated RAIT at doses of 2x 40–50 mCi/m2 (3 mos apart) post salvage resection of LM. Methods: To date, 26 pts (8x f, 18x m; age: 63 ± 9 ys) who underwent surgery for CRC-LM have received the first dose of 131I-labetuzumab (Immunomedics, In., NJ, USA), a humanized monoclonal antibody against CEA, within 2 months of LM surgery. Three months after the first RAIT, a second infusion of 40–50 mCi/m2 has been applied to all pts after completion of standardized re-staging procedures. Results: The primary tumor sites were 17 colonic and 9 rectal cancers; primary tumor stages were 5x UICC-II, 7x UICC-III, 14x UICC-IV. 13 pts received adjuvant therapy. In 11 pts preoperative chemotherapy (FOLFOX or FOLFIRI) was given to achieve resectability of bilobular LM. After resection of LM (y)mTNM tumor stages were 1x mTNM-I, 6x mTNM-II, 6x mTNM-III and 4x mTNM-IV, respectively. After first RAIT, hematologic Grade 3 and 4, toxicity (WBC/platelet count) occurred in 8/14 and 5/3 pts, respectively. No cumulative toxicity was seen after repeated RAIT, with complete bone marrow recovery observed in all cases so far. To date, all pts are alive. Of the total, 17 pts received RAIT with adjuvant intention (as classified by FDG-PET and CT scans at pre-RAIT re-staging). In these, DFS was 70% post salvage resection of LM during ongoing follow-up of 15 months (median; range: 4–23 mos). As of Dec. 20, 2006, cancer recurrence was detected in 5/17 pts (3x pulmonary, 1x intrahepatic, 1x both) and in 4 pts R0-resection of distant metastases was done. 1 patient with pulmonary and intrahepatic relapses receives polychemotherapy with palliative intention. The pts‘ compliance to repeated RAIT has been 100%. Conclusion: RAIT re-treatment to date appears to be safe, feasible, and well accepted. Extended follow-up of the encouraging survival data will be presented.

No significant financial relationships to disclose.

Growth hormone response in low-dose apomorphine test correlates with nigrostriatal dopamine transporter binding in patients with Parkinson’s disease

Challenge with low-dose apomorphine causes a rise in growth hormone (GH) in patients with Parkinson's disease (PD). We studied 18 patients with early PD, who showed an increase of GH in the low-dose apomorphine test, by means of [(123)I] FP-CIT-SPECT. The mean specific dopamine transporter binding of the 18 patients was 1.50 +/- 0.56 in the striatum, 1.20 +/- 0.59 in the putamen, and 1.76 +/- 0.59 in the caudate nucleus. The increase of GH (1.05 +/- 1.01 ng/ml at baseline to 9.46 +/- 6.36 ng/ml 45 min after apomorphine injection; p < 0.001) was significant. There was a significant negative correlation of the increase of GH with the mean specific dopamine transporter binding in all three regions (r between -0.490 and -0.587; p between 0.04 and 0.01). Challenge with low-dose apomorphine may therefore be used as an indirect tool to measure the extent of nigrostriatal neurodegeneration in early PD.

Incidence of Radioiodine Induced Graves' Disease in Patients with Multinodular Toxic Goiter

In this study, we assessed the incidence of Graves' disease (GD) following radioiodine therapy (RIT) in a large cohort of well characterized patients with autonomy in comparison to the clinical course of control patients with thyroidal autonomy not definitively treated with (131)I or surgery. 622 consecutive patients were treated with (131)I for autonomy (unifocal: n = 321; multifocal: n = 199; disseminated: n = 102) and followed up for at least 6 months post RIT. 108 consecutive patients with autonomy not definitively treated (unifocal: n = 49; multifocal: n = 42; disseminated: n = 11) followed up for at least 6 months served as controls. Initial evaluation and follow-up included determination of FT3, FT4, TSH, autoantibodies against the thyroid peroxidase (anti-TPO) and TSH-receptor antibodies (TRAb) by highly sensitive radio receptor-assay, quantitative thyroid scintigraphy and sonography. After 6 months, GD was newly diagnosed in 1/321 patients with unifocal autonomy, in 1/199 patients with multifocal autonomy and in 0/108 control patients. In patients with disseminated autonomy (group C), GD was diagnosed significantly more often compared to the other groups (5/102 patients; 4,1 %; p < 0.05). In conclusion, RIT may induce Graves' disease in a few cases with toxic multinodular goiter. The incidence in this population is small. Compared with patients suffering from uni- or multifocal autonomy, subjects with disseminated autonomy have a more than tenfold higher risk for the development of GD.

Phase II trial of repeated carcinoembryonic antigen (CEA) radioimmunotherapy (RAIT) with 131I-Labetuzumab post salvage resection of colorectal metastases in the liver

13572

Background: Complete resection of liver metastases (LM) remains the treatment of choice for colorectal cancer (CRC). As shown recently (Liersch et al., JCO 2005; 23:6763–70), RAIT with a single application of the humanized monoclonal anti-CEA antibody, 131I-labetuzumab, improved both the median overall survival (OS) and 5-yr survival rates significantly in patients post salvage resection of LM. The major adverse side effects (≤ grade 3 CTC) were transient myelosuppression and/or thrombocytopenia in patients receiving 40 to 60 mCi/m2 of 131I-labetuzumab. These encouraging results stimulated the current ongoing Phase-II trial to evaluate the safety of repeated RAIT at doses of 2 × 50 mCi/m2 (3 mos apart), post salvage resection of LM. Methods: At present, 13 patients (primary CRC: 8x UICC stage IV, 1× UICC stage III and 4× UICC stage II) who underwent surgery for LM of CRC (postsalvage mTMN stages: 4× mT4, 2× mT3, 6× mT2, 1× mT1) have received the first dose of 50 mCi/m2 131I-labetuzumab within 2 mos of LM surgery. Three months later, a second infusion of 50 mCi/m2 has already been given to 5 pts. In two, a dose reduction to 40 mCi/m2 was performed. At re-staging CT and PET scans) for the 2nd RAIT, in one patient pulmonary metastases were diagnosed and in another patient a re-resection of hepatic relapse was performed. Results: In the previous trial, at a median follow-up of 67 mos, the median OS from the first liver resection for 19 pts treated with single-dose RAIT was 68.0 mos and median DFS was 18.0 mos. Also, 5-year survival was achieved by 51.3% of RAIT pts independently of bilobar involvement, size and number of LM, or resection margins. In the current study with repeated RAIT, transient grade-4 myelosuppression (2 cases in combination with a myelotoxic thiamazol medication) occurred in 4/13 pts after the first dose (1× grade 4 thrombocytopenia). No cumulative toxicity was seen in 6 of 7 RAIT-re-treated patients. Complete bone marrow recovery was observed in all 6 cases within 5–12 weeks; in one pt severe neutropenia persisted to about week 16 post 2nd RAIT. As of January, 2006, patient compliance was 100%. Conclusion: RAIT re-treatment to-date appears to be safe, feasible, and well accepted. Extended follow-up data are being collected.

[Table: see text]

Tandem HD-chemotherapy and myeloablative radioimmunotherapy with 131I-anti-CD20 rituximab in relapsed and refractory B-cell lymphoma: Results of a phase II study of the German RAIT Study Group

13007

Background: Radioimmunotherapy has been shown to be effective in CD20 + B-cell lymphomas. Both non-myeloablative as well as myeloablative regimens have been employed for low grade and high grade lymphomas with impressive response rates and remission durations. Recently, the Press group and our group published data on myeloablative 131-I-anti-CD20 RAIT with high response rates and favourable long term survival especially in follicular lymphomas and transformed FL. Therefore, a phase II study is currently being done within the German Radioimmunotherapy Group, interim analysis data are presented. Methods: Patients were to receive R-Dexa-BEAM, followed by BEAM and HD-RAIT 2–6 months after BEAM. 131-I-Rituximab was administered with a maximum kidney and lung dose of 25 Gy. Sample size was calculated to be 16 to evaluate toxicity and feasibility of the tandem approach as primary endpoint. Results: 16 pts with relapsed (14) or primary refractory (2) B-cell lymphomas (FLI,II: 4pts; DLBCL: 4pts (all early relapses); transformed FL: 6 pts; MCL:1 pt, marginal zone lymphoma: 1 pt) were treated with 1 (15 pts) or 2 cycles (1 pt) of R-Dexa-BEAM. 13/16 pts achieving PR (5) or CRu (8) were treated with BEAM, 2 pts with PD and 1 with subdural hematoma were drop outs. After BEAM, 9/13 pts were in CR, 3/13 PR, 1/13 PD. Of 12 responding pts, 6 received HD-RAIT (1 pancytopenia, 1 hepatic, 2 pulmonary toxicity, 3 too early). After HD RAIT, 5/6 pts were in CR, 1 in PR. 4/6 pts (3 CR, 1 PR) are alive for 22–31 months, 2 pts died in CR, 1 of interstitial lung disease 2 months after HD-RAIT, 1 pt of pneumonia 8 months after HD-RAIT. Conclusions: Myeloablative RAIT is a feasible and effective treatment modality for relapsed poor prognosis CD20+ B-NHL not having severe toxicity due to the salvage regimen and HD-chemotherapy. HD RAIT offers the potential for long term relapse free survival. Final analysis of toxicity and outcome of this phase II study will be presented at the meeting.

No significant financial relationships to disclose.

[Improvement of tomographic reconstruction in bone SPECT]

AIM

The comparison between iterative reconstruction and filtered backprojection in the reconstruction of bone SPECT in the diagnosis of skeletal metastases.

PATIENTS, METHODS

47 consecutive patients (vertebral segments: n = 435), with suspected malignancy of the vertebral column, were examined by bone scintigraphy and MRI (maximal interval between the two procedures +/- 5 weeks). The SPECT-data were reconstructed with an iterative algorithm (ISA) and with filtered backprojection. We defined semiquantitative criteria in order to assess the quality of the tomograms. Conventional reconstruction was performed both by a Wiener-filter and a low-pass-filter. Iterative reconstruction was performed by the ISA algorithm. The clinical evaluation of the different reconstruction algorithms was performed by MRI as the gold-standard.

RESULTS

Sensitivity (%): 87.3 (ISA), 86.4 (low-pass), 79.7 (Wiener); specificity (%): 95.3 (ISA), 95 (low-pass), 85.4 (Wiener). The sensitivity of iterative reconstructed SPECT and low-pass reconstructed SPECT was significantly higher (p < 0.05) compared with the sensitivity of SPECT reconstructed by the Wiener-filter. The specificity of iterative reconstruction ISA and low-pass-filter reconstructed SPECT were significantly higher compared with the SPECT data reconstructed by the Wiener-filter. ISA was significantly superior to the Wiener-SPECT relating to all criteria of quality. Iterative reconstruction was significantly superior to the low-pass-SPECT relating to 2 of 3 criteria. In addition the Wiener-SPECT was significantly inferior to the low-pass-SPECT regarding to 2 of 3 criteria.

CONCLUSION

In our series the iterative algorithm ISA was the method of choice in the reconstruction of bone SPECT data. In comparison with conventional algorithms ISA offers a significantly higher quality of the tomograms and yields a high diagnostic accuracy.

Expression of the sodium iodide symporter in differentiated thyroid cancer: clinical evidence

AIM

Molecular analysis of the expression of the sodium iodide symporter (NIS) in 32 patients with differentiated thyroid cancer (DTC) and correlation with scintigraphic findings ((131)I,(123)I) in 19 (59.4%) of them.

PATIENTS, METHODS

NIS expression of 27 primary tumours, 13 lymphnodes and 18 distant metastases was determined by immunostaining using a murine monoclonal anti-NIS-antibody. NIS expression and radionuclide uptake of metastases were analysed by a semiquantitative visual score. Patients were divided into two subgroups: Group 1 (n = 8 patients): indirect correlation of radioiodine uptake (RIU) of subsequent metastases with NIS expression of 7 primary tumours and 3 metastases; Group 2 (n=11 patients): direct correlation of radionuclide uptake with NIS expression of 19 metastases which were excised after imaging.

RESULTS

49 of 58 specimens (84.5%) were NIS-positive. A preserved NIS-expression was found in 12 primary tumours and 8 of 10 (80%) synchrone and 6 of 7 (85.7%) metachrone metastases. Group 1 revealed a 100% positive predictive value (PPV) of a preserved NIS expression in the primary tumour regarding radioiodine uptake in metastases while a lack of NIS expression in the primary tumor did not reliable predict a loss of the metastases' ability to concentrate radioiodine. In group 2, only 11 of 19 (57.9%) specimens showed a concordant NIS expression and RIU whereas in the remaining 8 cases without visible RIU NIS expression was still present.

CONCLUSIONS

NIS expression of the primary tumour and metastases in DTC is usually well preserved. We found a positive correlation between NIS expression of the primary and metastatic tissue but could not identify such well correspondence between NIS expression and the RIU of subsequent metastases.

Diagnostic 123I and 131I activities and radioiodine therapy. Effects on urinary iodine excretion in patients with differentiated thyroid carcinoma

AIM

Urinary iodine excretion (UIE) provides information about iodine supply and release. In the present study we investigated effects of the application of different radioiodine isotopes on UIE in patients with differentiated thyroid carcinoma (DTC).

PATIENTS, METHODS

In 91 consecutive patients with DTC UIE, measured as iodine/creatinine ratio, was determined before and after application of 123I and 131I for diagnostic or therapeutic purposes. Additionally, remnant volume (V) was determined prior to therapy. Group A consisted of 33 patients with supposed successful ablation of DTC. These patients received 370 MBq 131I for diagnostic use and served as controls. 58 patients (group B) with remnants, relapses and metastases received 370 MBq 123I for diagnostics prior to therapy with 1.5-22.2 GBq 131I. Factors influencing individual changes in urinary iodine excretion (deltaUIE) were investigated by using non-parametric tests.

RESULTS

In group A UIE did not change significantly after application of 131I. As well, UIE remained unchanged after diagnostic application of 123I in group B. In contrast, UIE increased significantly already 24 h after therapeutic application of 131I in this group. In patients with small remnants (V < 2.5 ml) a significant but only moderate increase of UIE could be observed (average increase: 47 microg I/g crea). In patients with larger remnants, with relapses or metastases increase of UIE values was significant and more pronounced.

CONCLUSIONS

It was confirmed that UIE increased significantly during radioiodine therapy in patients with DTC and radioiodine-accumulating tissue. The increase of UIE after therapeutic administration of radioiodine can be explained by the disintegrated thyroid follicles in thyroid remnants. The radioiodine-induced iodine release may be one reason for thyroid "stunning" even after application of diagnostic amounts of 131I.

Diagnosis and follow up of aortitis in the elderly

OBJECTIVES

To evaluate the correlation of MRI and [(18)F]FDG-PET scans with the clinical course and inflammatory markers in patients with aortitis.

METHODS

Eight patients with aortitis presenting with unspecific GCA-like symptoms were examined. Aortitis was diagnosed and followed up by [(18)F]FDG-PET and MRI. The aorta was divided into three vascular regions (ascending aorta, aortic arch, and descending aorta) to localise the aortic inflammation and compare both imaging techniques.

RESULTS

were correlated with clinical and laboratory examinations.

RESULTS

At diagnosis, 20/24 vascular regions from eight patients were positive by [(18)F]FDG-PET scan and 15/21 aortic regions by MRI. Patients were treated with corticosteroids and followed up for a mean (SD) of 13.3 (4.7) months. In [(18)F]FDG-PET, 11/20 (55%) initially pathological aortic regions returned to normal in the follow up examination, which correlated closely with the clinical and laboratory follow up examination. Conversely, in MRI, 14/15 initially affected vascular regions were unchanged.

CONCLUSIONS

[(18)F]FDG-PET and MRI are both effective techniques for detecting early aortitis and have a high correlation with laboratory inflammatory measures. However, during the follow up examination, [(18)F]FDG-PET uptake decreased in line with the clinical symptoms and inflammatory serum markers, whereas MRI scans gave more static results.

Quantitative thyroid scintigraphy for the differentiation of Graves' disease and hyperthyroid autoimmune thyroiditis

AIM

The TCTUs (global (99m)Tc-pertechnetate thyroid uptake under suppression) can be used as an estimate of the iodine clearance of non-TSH regulated tissue. High TCTUs levels are characteristic for Graves' disease (GD). Decreased uptake has been described in autoimmune thyroiditis (AIT). However, systematically investigated data in a larger series of AIT-patients with subclinical or overt hyperthyroidism are not published so far. The purpose of this study is the evaluation of the TCTUs in the differentiation between AIT and GD in patients with hyperthyroidism.

METHODS

We determined the TCTUs in 59 patients with untreated hyperthyroid GD and in 51 patients with AIT who had subclinical or manifest hyperthyroidism without medication. Patients with GD were characterized by the presence of hyperthyroidism, decreased echogenicity of the thyroid, elevation of TSH-receptor autoantibodies (TRAb). AIT was defined by a decreased echogenicity of the thyroid, absence of elevated TSH-receptor autoantibodies (TRAb), autoantibodies against the thyroid peroxidase (anti-TPO) and spontaneous remission or development of subclinical hypothyroidism within 3 months.

RESULTS

Thyroid volumes of patients with AIT were significantly lower than those of patients with GD (p <0.05). TRAb levels were significantly higher in GD-patients (median: 19.5 U/ml; range: 15.3-35 U/ml) than in AIT-patients (median: 1.3 U/ml; range: 0-4.1 U/ml). 73% (38/59) of patients with GD had elevated anti-TPO levels. In these patients anti-TPO levels (median: 768 U/l; range: 83-6397 U/l) were not significantly different from anti-TPO levels of patients with AIT (median: 834 U/l; range: 107-8675 U/l; p = 0.17). TCTUs values of patients with AIT were significantly lower (p <0.05; median: 0.9%; range: 0.1-3.2%) than those of patients with GD (median: 5.7%; range: 1.9-28.3%).

CONCLUSION

In our patients quantitative thyroid scintigraphy with (99m)TcO(4)(-) offered rapid and reliable differentiation between hyperthyroid GD and AIT.

An in vitro study to compare 99mTc-stannous colloids and 99mTc-HMPAO for labelling human leukocytes

AIM

Aim of the present study was to compare in vitro the labelling efficiency (LE) and cell viability (TBE) of autologous leukocytes labelled with (99m)Tc-SnF(2) and (99m)Tc-HMPAO, and to evaluate the quantity and quality of spontaneously released (99m)Tc (SR) from labelled cells at several time points after labelling.

METHODS

A total of 14 patients with different diseases and 18 normal subjects were included in this study. A blood sample was collected from each patient; purified autologous leukocytes were divided into 2 samples and labelled with (99m)Tc-SnF(2) and (99m)Tc-HMPAO. LE was evaluated at the end of labelling and TBE and SR were evaluated at 10 min and 1 h, 2 h and 4 h after labelling.

RESULTS

LE of (99m)Tc-SnF(2)-WBC was higher than (99m)Tc-HMPAO-WBC (61.2+/-18.7% and 43.3+/-11.3; p<0.0001) and we found an inverse correlation between blood glucose and labelling efficiency for both methods (p=0.02). Minimal differences were also observed between 2 methods after 10 min and 1 h, as far as the cell viability is concerned. The percentage of radioactivity spontaneously released from (99m)Tc-SnF(2)-WBC was significantly higher compared to (99m)Tc-HMPAO-WBC at each time point. Radioactivity released from labelled cells was predominantly (99m)Tc-SnF(2) and (99m)Tc-HMPAO with few free (99m)Tc (<20%).

CONCLUSION

Both radiopharmaceuticals are not toxic for WBC. Labelling with (99m)Tc-SnF(2) give a higher LE than with (99m)Tc-HMPAO; however, radiolabelled colloids are more released from labelled cells over a period of 4 h. While (99m)Tc-HMPAO is physiological excreted into gastrointestinal tract, (99m)Tc-SnF(2) can be re-uptaken in vivo by reticulo-endothelial cells of liver and spleen. These findings suggest that (99m)Tc-SnF(2)-WBC might be better than (99m)Tc-HMPAO-WBC for studying inflammatory bowel diseases.

Erythropoietin: a candidate compound for neuroprotection in schizophrenia

Erythropoietin (EPO) is a candidate compound for neuroprotection in human brain disease capable of combating a spectrum of pathophysiological processes operational during the progression of schizophrenic psychosis. The purpose of the present study was to prepare the ground for its application in a first neuroprotective add-on strategy in schizophrenia, aiming at improvement of cognitive brain function as well as prevention/slowing of degenerative processes. Using rodent studies, primary hippocampal neurons in culture, immunohistochemical analysis of human post-mortem brain tissue and nuclear imaging technology in man, we demonstrate that: (1) peripherally applied recombinant human (rh) EPO penetrates into the brain efficiently both in rat and humans, (2) rhEPO is enriched intracranially in healthy men and more distinctly in schizophrenic patients, (3) EPO receptors are densely expressed in hippocampus and cortex of schizophrenic subjects but distinctly less in controls, (4) rhEPO attenuates the haloperidol-induced neuronal death in vitro, and (4) peripherally administered rhEPO enhances cognitive functioning in mice in the context of an aversion task involving cortical and subcortical pathways presumably affected in schizophrenia. These observations, together with the known safety of rhEPO, render it an interesting compound for neuroprotective add-on strategies in schizophrenia and other human diseases characterized by a progressive decline in cognitive performance.