Thyroid Peroxidase Antibody (TPO) as a Predictor of Radiation Induced Thyroid Dysfunction Among Nurses and Technicians Working in Mansoura Specialized Medical Hospital: Cross Sectional Study.

BACKGROUND: Thyroid gland is a probable goal tissue for radiation-related injury. Occupational exposure to ionizing radiation leads to thyroid dysfunction and exposure to high dose may lead to thyroid carcinoma. OBJECTIVE: Evaluation of the role of Thyroid peroxidase antibody as a predictor for thyroid dysfunction among nurses and technicians in the radiology department in Mansoura Specialized Medical hospital (MSMH). SUBJECTS AND METHODS: Subjects were Nurses and technicians who are working in (MSMH) with persistent daily duty in the last 3 years and fulfilling the inclusion and exclusion criteria. All subjects included in the study were recruited in one month and divided into two groups; Group 1: 50 subjects who were working in radiology, coronary angiography and ERCP unit, Radiation -exposed group. Group 2: 33 subjects who were working in In-patient departments and in out- patient clinics and not exposed to any type of radiation. Non fasting blood sample was taken from all enrolled subjects for measurement of TSH and Anti-TPO. RESULTS: TPO was positively and significantly correlated to age, TSH, duration of radiology/ y (r=0.388, 0.364, 0.342respectively) p value <0.05. Roc curve was done to detect the sensitivity and specificity of TSH in relation to TPO that revealed the cutoff value of TSH > 1.69 with Sensitivity and Specificity. PPV, NPV and accuracy at cutoff >1.69 were 70.6%, 51.5%, 42.8%, 77.3% and 58%. CONCLUSION: Working personnel with positive anti TPO and their TSH levels are more than 1.69 associated with symptoms of hypothyroidism, a trial of treatment is mandatory to relieve symptoms.

Redistribution of the nuclear protein IFI16 into the cytoplasm of ultraviolet B-exposed keratinocytes as a mechanism of autoantigen processing.

BACKGROUND: The skin has long been recognized as a prominent target tissue in systemic lupus erythematosus (SLE) which plays a crucial role in the initiation and perpetuation of the autoimmune reaction cascade as a consequence of ultraviolet (UV)-induced keratinocyte apoptosis. Antibodies against IFI16 (interferon-inducible protein 16) have been detected in the sera of patients with SLE. OBJECTIVES: To verify whether the induction of autoimmunity against IFI16 involves redistribution of this nuclear protein in keratinocytes during UVB-induced cell death. METHODS: An in vitro epidermal model was developed to investigate the fate of the IFI16 protein in keratinocytes after irradiation with UVB; both keratinocyte monolayers and human skin explants were used. IFI16 expression and localization were also analysed in diseased skin sections of patients with SLE. RESULTS: We demonstrated that IFI16, normally restricted to the nucleus, can be induced to appear in the cytoplasm under conditions of UVB-induced cell injury. This nucleus to cytoplasm translocation was also observed in skin explants exposed to UVB and in the diseased skin sections from patients with SLE. In addition, IFI16 was found in the supernatants of UVB-exposed keratinocytes. CONCLUSIONS: The finding that IFI16 is present in the cytoplasm of diseased skin cells from patients with SLE and the demonstration of IFI16 in the supernatants of UVB-exposed keratinocytes, suggest that UVB irradiation or other stimuli may favour an abnormal IFI16 presentation to the afferent limb of the immune system and potentially an autoimmune response against the protein itself.

UV-induced fragmentation of Cajal bodies.

The morphology and composition of subnuclear organelles, such as Cajal bodies (CBs), nucleoli, and other nuclear bodies, is dynamic and can change in response to a variety of cell stimuli, including stress. We show that UV-C irradiation disrupts CBs and alters the distribution of a specific subset of CB components. The effect of UV-C on CBs differs from previously reported effects of transcription inhibitors. We demonstrate that the mechanism underlying the response of CBs to UV-C is mediated, at least in part, by PA28gamma (proteasome activator subunit gamma). The presence of PA28gamma in coilin-containing complexes is increased by UV-C. Overexpression of PA28gamma, in the absence of UV-C treatment, provokes a similar redistribution of the same subset of CB components that respond to UV-C. RNA interference-mediated knockdown of PA28gamma attenuates the nuclear disruption caused by UV-C. These data demonstrate that CBs are specific nuclear targets of cellular stress-response pathways and identify PA28gamma as a novel regulator of CB integrity.

Ultraviolet B radiation-induced cell death: critical role of ultraviolet dose in inflammation and lupus autoantigen redistribution.

The nuclear self-Ags targeted in systemic lupus erythematosus translocate to the cell membrane of UV-irradiated apoptotic keratinocytes and may represent an important source of self-immunization. It is hard to understand how the noninflammatory milieu accompanying most apoptosis might provoke an immunogenic response leading to autoantibodies. We have found that the precise amount of keratinocyte UV exposure is crucial in determining the rate of apoptosis, the amount of inflammatory cytokine production, and the degree of autoantigen translocation. Low doses of UVB (

Fas ligand and Bax gene transcription contributes to Ro60 ribonucleoprotein redistribution in UV-A irradiated human keratinocytes.

OBJECTIVES: Ro ribonucleoproteins are of particular interest because they are serologic markers of photosensitive variants of lupus such as the subacute cutaneous lupus erythematosus (SCLE), in which the polycyclic skin lesions are triggered by exposure to the sun. We study the role of apoptosis in the expression of Ro antigen. METHODS: We used UV-A irradiated keratinocytes. RESULTS: We demonstrate in cultured human UVA-irradiated keratinocytes that the enhanced expression of Ro60 ribonucleoprotein is caused by antigenic redistribution consecutive to Fas-L and Bax gene activation.

Expression of SS-A/Ro and SS-B/La antigens in skin biopsy specimens of patients with photosensitive forms of lupus erythematosus.

CONTEXT: The reason that only some patients with lupus erythematosus (LE) develop autoantibodies to SS-A/Ro and SS-B/La antigens and photosensitivity is unknown. One hypothesis is that both events are related to the level of expression of these antigens in the skin. OBJECTIVE AND DESIGN: To test this hypothesis, we measured the expression of the 52-kd SS-A/Ro, 60-kd SS-A/Ro, and 48-kd SS-B/La antigens in normal sun-protected and sun-exposed skin in 14 patients with LE with photosensitivity, 12 patients with LE without photosensitivity, and 4 normal individuals. The presence of circulating antibodies to these antigens was measured in all patients. SETTING: Outpatient clinic in an academic medical center. RESULTS: We found that the expression of the 52-kd SS-A/Ro, 60-kd SS-A/Ro, and 48-kd SS-B/La antigens in skin biopsy specimens obtained from the same site was 4- to 10-fold higher in patients with LE with photosensitivity than in those patients with LE without photosensitivity (P<.001). Antigen expression was highly correlated with the presence and titer of circulating anti-SS-A/Ro and anti-SS-B/La antibodies (P<.001). CONCLUSIONS: These findings indicate that photosensitivity and the presence and titer of circulating anti-SS-A/Ro and anti-SS-B/La antibodies are both directly correlated with the expression of accessible and immunoreactive SS-A/Ro and SS-B/La antigens in the skin specimens of patients with LE. Thus, the expression of these antigens in keratinocytes may be an important determinant of the development of both SS-A/Ro and SS-B/La autoantibodies and of photosensitive forms of LE.

Ultraviolet B irradiation and cytomegalovirus infection synergize to induce the cell surface expression of 52-kD/Ro antigen.

Cultured human fibroblasts (MRC-5) have been previously demonstrated to express calreticulin, but not Ro autoantigen, on their surface after human cytomegalovirus (CMV) infection. The present study addresses the question of whether other stimuli, alone or in combination with CMV, can induce the surface expression of Ro autoantigens on human fibroblasts. Using a fixed-cell ELISA to detect autoantigen expression, a synergistic effect between ultraviolet B (UVB) exposure and CMV infection on the surface expression of 52-kD/Ro antigen, but not 60-kD/Ro or calreticulin, was observed. The enhanced expression of 52-kD/Ro antigen was significant and specific, compared with untreated cells, cells infected with CMV alone or irradiated with UVB only, and cells subjected to other treatments, such as low pH. Immunofluorescence studies confirmed these findings and indicated that cells expressed 52-kD/Ro protein on their surface at 24 h after a combined UVB and CMV treatment. These studies provide evidence that synergy between UVB irradiation and CMV infection may play a role in the induction of cell surface expression of the human autoantigen, 52-kD/Ro.

Stress-induced cell surface expression and antigenic alteration of the Ro/SSA autoantigen.

Recent studies have shown that Ro/SSA autoantigen is heterogeneous. There are two isoform families; the 60 kD forms (Ro60) and the 52 kD forms (Ro52). Recently we have found that autoantibodies to the Ro/SSA proteins are conformation dependent. Anti-Ro60 antibodies are mainly directed to the native protein and conversely anti-Ro52 antibodies are directed only to the denatured protein. It has been known that UV irradiation to cultured keratinocytes induces cell surface expression of Ro/SSA and this phenomenon has been thought to be related with photosensitivity in patients with anti-Ro/SSA antibodies. We studied the quantitative and qualitative changes of the Ro/SSA protein induced by stress, such as with heat shock and UV irradiation, and found that only Ro52 could be expressed on the cell surface of human peripheral lymphocytes by either heat shock or UV irradiation. Moreover, flow cytometric analysis revealed that HS-treated and UV-treated lymphocytes could be stained with patient sera, and by using a technique which combined immunoprecipitation and Western immunoblotting, it has been confirmed that Ro52 expressed on the cell surface can be recognized by anti-Ro/SSA antibodies in native form while cytoplasmic Ro52 cannot be recognized. These data suggest that Ro52 can be antigenic in vivo when expressed on the cell surface and may explain the mechanism of direct tissue damage by anti-Ro/SSA antibodies.

Impact of ultraviolet radiation on the cellular expression of Ro/SS-A-autoantigenic polypeptides.

Modulation of Ro/SS-A autoantigens in epidermal keratinocytes has been implicated in the pathogenesis of photosensitive forms of Ro/SS-A-antibody-associated cutaneous lupus erythematosus (LE) such as subacute cutaneous LE and neonatal LE. Since Ro/SS-A ribonucleoprotein particles have recently been shown to be very complex molecular structures, we have performed studies to determine whether the expression of three of the Ro/SS-A antigenic polypeptides might be differentially regulated in transformed human epidermal keratinocytes following UVB radiation. Our findings indicate that both total cellular and cell surface levels of calreticulin are upregulated by UVB exposure more so than are either the 52- or 60-kD Ro/SS-A antigens. These results suggest that calreticulin could be a critical component of the Ro/SS-A ribonucleoprotein complex involved in the pathogenesis of Ro/SS-A-antibody-associated LE skin lesions.

[Antibodies to the thyroid microsomal antigen in children and adolescents subjected to radiation exposure as a result of the accident at the Chernobyl Atomic Electric Power Station]. / Antitela k mikrosomal'nomu antigenu shchitovidnoi zhelezy u detei i podrostkov, podvergshikhsia radiatsionnomu vozdeistviiu v rezul'tate avarii na Chernobyl'skoi AES.

For evaluation of the possibility of the appearance of autoimmune thyroiditis in children and juveniles lived in the areas of Kaluga Province [correction of region] suffered from the Chernobyl accident the content of antibodies to human thyroid microsomal antigen was investigated. Percentage of positive sera varied from 4.8% to 1.2% during 6 years. There is significant difference in the frequency of the antibody appearance between persons suffered from radioactive iodine and unsuffered ones. Correlation between levels of antimicrosomal antibodies and radiation dose obtained from incorporated radioactive iodine was not estimated.

[Dynamics in changes of a1-thymosin level under irradiation of mice thymus in vivo and in vitro: relation to the antibody-antigen production of epithelial thymus reticulum]. / Dinamika izmenenii urovnia a1-timozina pri obluchenii timusa myshei in vivo i in vitro: sviaz s produktsiei autoantitel k antigenam épitelialnogo retikuluma timusa.

In 3- and 9-month experiments with mice, a study was made of the effect of radiation on serum alpha 1-thymosine concentration after whole-body irradiation and local exposure of the thymus at doses of 1-20 Gy. The effect of 137Cs-gamma-rays on the in vitro cultured thymus stroma cells, with respect to alpha 1-thymosine secretion, and the influence of local irradiation of the thymus of production of autoantibodies that react with epithelial thymus cells were studied. Both whole-body irradiation and local exposure of the thymus were shown to cause changes in the alpha 1-thymosine content of the blood plasma. The direction and dynamics of the changes observed are different with whole-body and local exposure. Irradiation of cultured thymus cells of mice causes alterations in alpha 1-thymosine secretion, that is, stimulation at a dose of 1 Gy and inhibition at higher doses. With respect to dose- and time-response, these changes are closer to those observed in alpha 1-thymosine concentration in mouse serum after whole-body irradiation than after local exposure of the thymus in vivo. At remote times after local irradiation of the thymus with doses of 1-10 Gy, autoantibodies are found in mouse serum that react with epithelial cells of the thymus stroma. Autoantibodies are absent at doses of 15 and 20 Gy.

The effects of hormonal and other stimuli on cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: their possible role in the induction of cutaneous lupus lesions.

Ultraviolet B light (UVB) has previously been shown to induce the expression of the extractable nuclear antigens (e.g. Ro/SSA) on the surfaces of human keratinocytes in vitro. This study assessed whether injurious, metabolic, inflammatory, immunological or hormonal stimuli would also induce this expression or modulate that produced by UVB. No stimulus initiated expression alone, but 17-beta oestradiol doubled that found in response to UVB. These findings confirm the potential role of UVB in the initiation and potentiation of cutaneous lupus lesions and may help to explain the female preponderance of the disease.

Ultraviolet radiation (UVR) induces cell-surface Ro/SSA antigen expression by human keratinocytes in vitro: a possible mechanism for the UVR induction of cutaneous lupus lesions.

Antinuclear antibodies are useful markers of connective tissue disease. In this study, UVB but not UVA induced the expression of Ro/SSA antigen on keratinocyte surfaces in vitro. This expression was also found with the extractable nuclear antigens RnP and Sm, but not with single or double-stranded DNA. The expression was prevented by blocking protein synthesis, suggesting that it was an active process. The results suggest that UVB exposure may result in the expression of Ro/SSA antigen on the surfaces of basal keratinocytes in vivo. This antigen could then bind circulating antibody leading to the cutaneous lesions in neonatal and subacute cutaneous lupus erythematosus.

The small nuclear ribonucleoprotein SS-B/La binds RNA with a conserved protease-resistant domain of 28 kilodaltons.

SS-B/La is a nuclear protein of 48 kilodaltons with two structural domains of Mr 28,000 and Mr 23,000 generated by proteolytic cleavage. UV irradiation was used to cross-link preexisting intracellular La-RNA complexes. Subsequent protease digestion and diagonal gel electrophoresis showed that the RNA-binding site resided in the nonphosphorylated, methionine-rich 28-kilodalton domain.

An animal model of antibody binding in cutaneous lupus.

To study antibody binding in cutaneous lupus, we used human skin grafted onto nude mice. By immunofluorescence examination, mice injected with anti-Ro (SS-A) sera from subacute cutaneous or neonatal lupus erythematosus patients showed evidence of human IgG deposited in the skin, while mice injected with anti-native DNA or normal sera did not. We present evidence that there is specific binding of anti-Ro (SS-A) antibodies to Ro (SS-A) antigen in the skin, and we propose that these antibodies may be directly involved in cutaneous disease.

Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies.

We used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. None of the monoclonal autoantibodies appeared to bind to a significant percentage of cells of relatively small cell size, either before or after culture. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Further experiments, including those using aggregated Ig to block antibody binding, strongly indicated that anti-histone antibody binding was not Fc receptor mediated. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations (0.25 micrograms/ml) of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases.