Two lymphoma histotypes and papillary thyroid carcinoma coexisting on Hashimoto ground: a case report and review of the literature.

BACKGROUND: Papillary carcinoma is the most frequent type of thyroid carcinoma, while primary thyroid lymphoma is uncommon disease. The coexistence of these entities has already been described, and the common risk factor is considered Hashimoto thyroiditis. The two most frequent histotypes of primary thyroid lymphoma are diffuse large B-cell and mucosa-associated lymphoid tissue lymphoma, but the coexistence of both with papillary carcinoma is rarely reported. METHODS: We present a case of a previously healthy 57-years old male with rapidly growing lump on the right side of the neck. Ultrasonography revealed nodules in both thyroid lobes. Fine needle aspiration cytology and pertechnetate scintigraphy were performed. Due to the Bethesda T-5 in the "cold" nodule of the right lobe, surgery with histopathological and immunohistochemistry analysis was indicated. RESULTS: Histopathological and immunohistochemistry methods confirmed concomitant malignancies in the thyroid gland: diffuse large B-cell lymphoma and papillary carcinoma in the right, and mucosa-associated lymphoid tissue lymphoma in the left lobe with Hashimoto thyroiditis in the remaining tissue. Patient underwent therapy procedures and was without signs of local recurrence or metastatic spread on subsequent follow-up. CONCLUSIONS: Sudden appearance of the neck mass in patients with Hashimoto thyroiditis should raise suspicion on primary thyroid lymphoma and be promptly taken in the diagnostic workup, including fine needle aspiration cytology. Pathology with immunohistochemistry is crucial for further clinical decision making. Since the standardized protocol in management of these complex patients is missing, personal approach and close collaboration between cytologist, pathologist, surgeon, haematologist and nuclear medicine specialist is essential.

The significance of serum thyroglobulin measurement before and after the treatment of toxic nodular goiter with 131I.

OBJECTIVES: Thyroglobulin is routinely used as a tumor marker in follow up of patients with thyroid carcinoma, but is also elevated in patients with toxic nodular goiter. The aim of this study was to evaluate the role of thyroglobulin measurement prior to and after the radioiodine therapy (RIT) in patients with toxic nodular goiter and to compare the results with the therapy outcome. PATIENTS AND METHODS: In 109 patients with toxic nodular goiter (102 females, 7 males, aged 45-85 years), 61 with multinodular toxic goiter and 48 with toxic adenoma, thyroglobulin level was measured before RIT and during the first 12 months after the treatment and compared to therapy outcome, defined as euthyroid, hypothyroid and persistent hyperthyroidism. RESULTS: In patients with euthyroid and hypothyroid outcome, a significant fall of thyroglobulin level was noted during the first 12 months after RIT, more prominent in the latter group. In patients with persistent hyperthyroidism, the initial thyroglobulin level was higher than in other two groups and no significant decrease was noted by the end of the first year after therapy, especially in patients with multinodular toxic goiter. CONCLUSIONS: The significant fall of thyroglobulin after RIT observed in patients in whom euthyroidism and hypothyroidism was achieved indicates that thyroglobulin values can be related to the treatment outcome. In patients with high initial thyroglobulin levels (above 400 ng/l), and possible unfavorable RIT outcome, higher radioiodine activities or other treatment options might be considered.Video abstract: http:/links.lww.com/NMC/A163.

Landmarks of endosomal remodeling in the early phase of cytomegalovirus infection.

Cytomegaloviruses (CMVs) extensively rearrange the cellular membrane system to develop assembly compartment (AC), but the earliest events in this process are poorly characterized. Here, we demonstrate that murine CMV (MCMV) infection restrains endosomal trafficking of cargo molecules that travel along the recycling (TfR and MHC-I) and the late endosomal (EGFR, M6PR, Lamp1) circuit. Internalized cargo accumulates in Arf6-, Rab5-, Rab22A-, and Rab11-positive and Rab35-, Rab8-, and Rab10-negative juxtanuclear endosomes, suggesting the disruption of Arf/Rab regulatory cascade at the stage of sorting endosomes and the endosomal recycling compartment. Rearrangement of the endosomal system is initiated by an MCMV-encoded function very early in the infection. Our study, thus, establishes a set of landmarks of endosomal remodeling in the early phase of MCMV-infection which coincide with the Golgi rearrangement, suggesting that these perturbations are the earliest membrane reorganizations that may represent an initial step in the biogenesis of the AC.

Endosomal trafficking of open Major Histocompatibility Class I conformers--implications for presentation of endocytosed antigens.

Major Histocompatibility Class I (MHC-I) molecules are present at the cell surface either as fully conformed trimolecular complexes composed of heavy chain, beta-2-microglobulin (ß2m) and antigenic peptide or as various open forms, devoid of the peptide and/or ß2m. While the role of fully conformed MHC-I is well studied, the physiological role of open conformers is neglected. We have shown that fully conformed MHC-I and open MHC-I conformers segregate at the PM and during endosomal trafficking resulting in the exclusion of open MHC-I from the early endosomal/juxtanuclear recycling route. As a result, open MHC-I conformers are internalized with a higher rate than fully conformed counterparts. Although the majority of internalized open MHC-I is directed into the acidic late endosomal (LE) compartments, only a fraction of them is degraded. Namely, a significant fraction of open MHC-I is present in a subset of LEs with the capacity of recycling and/or exocytosis. Therefore, it should be examined whether exogenous peptide loading may occur during traveling of MHC-I proteins through LE compartments, especially in a subset of less acidic LEs that detach from the core of perinuclear acidic LEs and migrate toward the cell periphery. Given that the acidic LE environment is not favorable for peptide loading, an endosomal compartment with the recycling capacity and less acidic environment that allows stabilization of newly formed trimolecular complexes is proper site for exogenous peptide loading. We propose that a LE compartment which collect and retain open MHC-I conformers should be taken into consideration as a site of exogenous peptide loading.

Early endosomal rerouting of major histocompatibility class I conformers.

Major histocompatibility class I (MHC-I) molecules are present at the cell surface both as fully conformed trimolecular complexes composed of heavy chain (HC), beta-2-microglobulin (ß2m) and peptide, and various open forms, devoid of peptide and/or ß2m (open MHC-I conformers). Fully conformed MHC-I complexes and open MHC-I conformers can be distinguished by well characterized monoclonal antibody reagents that recognize their conformational difference in the extracellular domain. In the present study, we used these tools in order to test whether conformational difference in the extracellular domain determines endocytic and endosomal route of plasma membrane (PM) proteins. We analyzed PM localization, internalization, endosomal trafficking, and recycling of human and murine MHC-I proteins on various cell lines. We have shown that fully conformed MHC-I and open MHC-I conformers segregate at the PM and during endosomal trafficking resulting in the exclusion of open MHC-I conformers from the recycling route. This segregation is associated with their partitioning into the membranes of different compositions. As a result, the open MHC-I conformers internalized with higher rate than fully conformed counterparts. Thus, our data suggest the existence of conformation-based protein sorting mechanism in the endosomal system.

Comparative study of frequency of different lymphocytes subpopulation in peripheral blood of patients with prostate cancer and benign prostatic hyperplasia.

PURPOSE: Benign prostatic hyperplasia (BPH) and prostate cancer (PC) are the most common urologic diseases among men over fifty and, until recently, they were considered to be caused by the impaired immune response. Despite many studies designed to investigate T-cell-based antitumor immunity, the role of innate immune cells in BPH and PC is still poorly understood. In this study the frequency of different leukocytes subpopulation in peripheral blood of BPH, PC patients and in healthy volunteers was analysed and compared. METHODS: In a cross-sectional study 60 subjects were enrolled (20 patients with BPH or with PC and 20 healthy volunteers). Peripheral blood mononuclear cells (PBMC) were isolated and the percentage of T lymphocytes, natural killer (NK) and NKT cells, as well as subsets of T lymphocytes [CD3(+)CD56(-)CD4(+), T(regs) (CD4(+)CD25(+)FoxP3(+)) and CD3(+)CD56(-)CD8(+)] and NK cells (CD3(-)CD56(+dim) and CD3(-)CD56(+bright)) were analysed by flow cytometry. Intracellular content of interleukin-4 (IL-4) and interferon gamma (IFNγ in T lymphocytes, NK and NKT cells were also detected. RESULTS: The percentage of T lymphocytes and their subsets in peripheral blood lymphocytes did not differ among investigated groups, while the frequency of Tregs was the highest in PC patients. The percentage of NK cell and their subsets did not differ among investigated groups. Negative correlation between PSA value, percentage of T lymphocytes and NK cells was observed only in PC patients. Highly positive correlation between the PSA value and the percentage of Tregs was found in PC patients. CONCLUSION: Different frequencies in distinctly lymphocyte subpopulation in peripheral blood of healthy men, BPH and PC patients could be responsible for occurrence and progression of prostatic hyperplasia or tumour. Due to the ability of tumours to suppress the cognate T cell immune response, the cells of innate immunity (NKT and Tregs) may be playing a key role in the immunopathogenesis of PC and BPH.

Segregation of open Major Histocompatibility Class I conformers at the plasma membrane and during endosomal trafficking reveals conformation-based sorting in the endosomal system.

Fully conformed Major Histocompatibility Class I molecules are complexes of heavy chain non-covalently associated with the peptide and beta-2-microglobulin. Conformational change in the extracellular domain of heavy chain leads to their disassembly and formation of open conformers, a process that physiologically occurs in normal cells and results in their presence at the cell surface. In this study we characterized endosomal trafficking of open conformers of a murine class I allele in order to examine whether conformational change in the extracellular domain of a membrane glycoprotein determines its endosomal sorting. Open conformers segregated from their fully conformed counterparts at the plasma membrane and in endosomes by sequestration in lipid-organized membrane environment. Consequently, open conformers constitutively internalized via distinct clathrin-independent endocytic carriers and converged into "classical" early endosomes together with transferrin receptor and cholera-toxin B subunit. In early endosomes, open conformers were excluded from recycling and diverted towards late endosomes. Due to lack of recycling, open conformers were constitutively internalized at a higher rate than full conformed proteins. Concanamycin A, methyl-ß-cyclodextrin and sphingomyelinase treatment prevented segregation of open conformers in vacuolar early endosomes indicating that acidic endosomal environment and membrane composition are critical for the maintenance of the sorting mechanism. In the absence of endosomal acidification open conformers partitioned into lipid disordered membrane composition of early endosomes. Thus, our data suggest for the existence of a lipid-dependent mechanism in the endosomal system that distinguish membrane proteins based on conformation of their extracellular domain.

Murine cytomegalovirus perturbs endosomal trafficking of major histocompatibility complex class I molecules in the early phase of infection.

Murine cytomegalovirus (MCMV) functions interfere with protein trafficking in the secretory pathway. In this report we used Δm138-MCMV, a recombinant virus with a deleted viral Fc receptor, to demonstrate that MCMV also perturbs endosomal trafficking in the early phase of infection. This perturbation had a striking impact on cell surface-resident major histocompatibility complex class I (MHC-I) molecules due to the complementary effect of MCMV immunoevasins, which block their egress from the secretory pathway. In infected cells, constitutively endocytosed cell surface-resident MHC-I molecules were arrested and retained in early endosomal antigen 1 (EEA1)-positive and lysobisphosphatidic acid (LBPA)-negative perinuclear endosomes together with clathrin-dependent cargo (transferrin receptor, Lamp1, and epidermal growth factor receptor). Their progression from these endosomes into recycling and degradative routes was inhibited. This arrest was associated with a reduction of the intracellular content of Rab7 and Rab11, small GTPases that are essential for the maturation of recycling and endolysosomal domains of early endosomes. The reduced recycling of MHC-I in Δm138-MCMV-infected cells was accompanied by their accelerated loss from the cell surface. The MCMV function that affects cell surface-resident MHC-I was activated in later stages of the early phase of viral replication, after the expression of known immunoevasins. MCMV without the three immunoevasins (the m04, m06, and m152 proteins) encoded a function that affects endosomal trafficking. This function, however, was not sufficient to reduce the cell surface expression of MHC-I in the absence of the transport block in the secretory pathway.

How activity of inflammatory bowel disease influences bone loss.

Bone loss is a common problem for individuals with inflammatory bowel disease (IBD). The aim of our study was to assess bone mineral density (BMD) in patients with IBD and to investigate the role of corticosteroid (CS) use and duration and activity of disease on BMD. Ninety-two patients (56 men and 36 women) with IBD, of whom 32 had ulcerative colitis (UC) and 60 had Crohn's disease (CD), underwent clinical assessment. Lumbar and femoral neck BMDs were measured by dual-energy X-ray absorptiometry. Osteopenia was observed in 14 patients (43%) with UC and in 24 patients (40%) with CD (p=0.187). Four patients (12%) with UC and 7 patients (11%) with CD had osteoporosis (p=0.308). Femoral BMD decreased in patients with long duration of CS use and correlated inversely with disease activity. Multiple regression analysis of BMD showed that statistically significant risk factors were duration of active disease and body mass index as well. Based on our results, it is necessary to take into account the risk of decreased BMD in patients with IBD. It is most important to achieve disease remission as soon as possible in addition to nutritional support.