Parasitic thyroid nodule in a patient with Hashimoto's chronic thyroiditis

A case of parasitic thyroid nodule is presented. The patient was a non symptomatic 53-year-old white woman, on irregular course of L-thyroxine to treat hypothyroidism due to Hashimoto's thyroiditis. Without a history of thyroid trauma or surgery, she presented a 1.6 x 0.7 x 0.5cm right pre-laryngeal lymph node-like mass which, on ultrasonography, appeared distinct from the gland. TSH, thyroid peroxidase antibody and thyroglobulin antibody serum levels were elevated and T4-free level was normal. Thyroid and total body 99mTc isonitrile scintiscan showed a topic thyroid without radionuclide uptake in the nodule. Fine-needle aspiration of the nodule showed epithelial cells with nuclear atypia and oncocytic changes plus intense lymphoid infiltration and germinative center formation, simulating lymph node metastasis of papillary thyroid carcinoma. Conventional biopsy revealed a parasitic thyroid nodule with Hashimoto's chronic thyroiditis. Parasitic thyroid nodule must always be remembered so that unnecessary surgical assessment and undesirable sequels may be avoided.

Reactivity of anti-thyroid antibodies to thyroglobulin tryptic fragments: comparison of autoimmune and non-autoimmune thyroid diseases

Studies concerning the antigenicity of thyroglobulin fragments allow the characterization of the epitopes but do not consider the role of heavier antigenic fragments that could result in vivo from the action of endoproteases. Here we assess the relative importance of the fragments obtained from thyroglobulin by limited proteolysis with trypsin and compare by immunoblotting their reactivity to serum from patients with autoimmune (Graves' disease and Hashimoto's thyroiditis) and non-autoimmune (subacute thyroiditis) disease. The results showed no difference in frequency of recognition of any peptide by sera from patients with autoimmune thyroiditis. In contrast, sera from patients with subacute thyroiditis reacted more frequently with a peptide of 80 kDa. These results suggest the presence of antibody subpopulations directed at fragments produced in vivo by enzymatic cleavage of thyroglobulin. This fragment and antibodies to it may represent markers for subacute thyroiditis.

Profile of thyroid hormones in breast cancer patients

Estrogen involvement in breast cancer has been established; however, the association between breast cancer and thyroid diseases is controversial. Estrogen-like effects of thyroid hormone on breast cancer cell growth in culture have been reported. The objective of the present study was to determine the profile of thyroid hormones in breast cancer patients. Serum aliquots from 26 patients with breast cancer ranging in age from 30 to 85 years and age-matched normal controls (N = 22) were analyzed for free triiodothyronine (T3F), free thyroxine (T4F), thyroid-stimulating hormone (TSH), antiperoxidase antibody (TPO), and estradiol (E2). Estrogen receptor ß (ERß) was determined in tumor tissues by immunohistochemistry. Thyroid disease incidence was higher in patients than in controls (58 vs 18%, P < 0.05). Subclinical hyperthyroidism was the most frequent disorder in patients (31%); hypothyroidism (8%) and positive anti-TPO antibodies (19%) were also found. Subclinical hypothyroidism was the only dysfunction (18%) found in controls. Hyperthyroidism was associated with postmenopausal patients, as shown by significantly higher mean T3 and T4 values and lower TSH levels in this group of breast cancer patients than in controls. The majority of positive ERß tumors were clustered in the postmenopausal patients and all cases presenting subclinical hyperthyroidism in this subgroup concomitantly exhibited Erß-positive tumors. Subclinical hyperthyroidism was present in only one of 6 premenopausal patients. We show here that postmenopausal breast cancer patients have a significantly increased thyroid hormone/E2 ratio (P < 0.05), suggesting a possible tumor growth-promoting effect caused by this misbalance.

Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.

Detection of anti-Giardia lamblia serum antibody among children of day care centers

OBJETIVES: To detect anti-Giardia lamblia serum antibodies in healthy children attending public day care centers and to assess serological tests as tools for estimating the prevalence of G. lamblia in endemic areas. METHODS: Three separate stool specimens and filter paper blood samples were collected from 147 children ranging from 0 to 6 years old. Each stool sample was processed using spontaneous sedimentation and zinc sulfate flotation methods. Blood samples were tested by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for Giardia IgG. RESULTS AND CONCLUSIONS: Of 147 individuals tested, 93 (63.3%) showed Giardia cysts in their feces. Using IIF and ELISA, serum antibodies were detected in 93 (63.3%) and 100 (68%) samples , respectively. Sensitivity of IIF and ELISA was 82% and 72%, respectively. However, ELISA revealed to be less specific (39%) than IIF (70%). IIF also showed a higher concordance with microscopic examination than ELISA.

Seroprevalence of Toxoplasma gondii IgG antibody in HIV/AIDS-infected individuals in Maputo, Mozambique

OBJECTIVE To analyze the prevalence of IgG antibodies to Toxoplasma gondii in patients infected with HIV/AIDS and the association of demographic and social variables. METHODS Descriptive cross-sectional study that included the analysis of sociodemographic data and laboratory findings of 200 patients infected with HIV/AIDS treated in a laboratory unit in Maputo, Mozambique, in 2010. Individual data for all participants were collected with a self-administered questionnaire. Plasma samples were tested for IgG testing of anti- T. gondii using hemagglutination for the analysis of antibodies. RESULTS The seroprevalence of IgG anti- T. gondii was 46.0% (95%CI 39.2;52.9), 39.3% (95%CI 29.5;50.0) in men and 50.9% (95%CI 41.9;59.8) in women, with no difference between sex (OR 1.30; 95%CI 0.95;1.77; p = 0.12). Ages ranged from 10 to 60 years, with a higher prevalence of infection in older age groups, but with no significant difference between them. Regularly consuming cattle meat (OR 1.74; 95%CI 1.04;2.89, p = 0.05), breeding cats/dogs (OR 6.18; 95%CI 3.60;10.62, p < 0.000) and having regular contact with soil (OR 3.38; 95%CI 2.19;5.21; p < 0.000) were significantly associated with risk of latent infection. CONCLUSIONS Toxoplasmosis is an infection with high prevalence in Mozambique. Cultural and behavioral aspects increase the risk. Toxoplasmosis can be responsible in our environment by the great burden of morbidity and mortality associated with meningoencephalic injuries in patients with HIV/AIDS.

Acute Hepatitis B in a patient previously positive for antibody to surface antigen (anti-HBs) determined by radioimmunoassay: case report and review of the literature

The determination of anti-HBs as a screening test before vaccination has been advisable in order to encounter immune individuals that don't need to receive vaccine protection. A case-report is presented and three other cases are reviewed from the literature. Anti-HBs was positive in these health-care personnels that developped typical acute B hepatitis. Different subtyping involving the d/y determinants were found in the first case, but false-positive anti-HBs even with high titres, determined by RIA, were found in the other cases. Concomitant determination of anti-HBc or absence of screening tests seem to be more reasonable policies until a low-cost and risk-free vaccine is produced.

Prevalence of antibody to hepatitis B virus in an urban population of northeast Brazil

A sample of 1,288 inhabitants of Salvador, Bahia, Brazil, were submitted to the determination of anti-HBs using radioimmunoassay procedure, and analysed according to age, sex and income. Overall prevalence of anti-HBs was 11,8%. ranging from 6,7% among children aged less than three years old to 26,1% among those aged 30 years and older. Males presented prevalence of anti-HBs similar to female individuals, and those with a higher income showed frequencies of anti-HBs greater than those with a lower income level. The following conclusions were drawn: The high prevalence of anti-HBs observed among children suggests early contact with hepatitis B virus, possibly due to vertical transmission and intrafamiliar dissemination of the disease; the frequency of anti-HBs increases with age; the lower prevalence of anti-HBs among those with low income suggests that this group may present higher prevalence of carriers of the hepatitis B virus surface antigen.

Antibody response to heat-inactivated hepatitis B vaccine (CLB-3mg) in hemodialysis patients and occupational risk personnel: a one year follow-up

Immune response against hepatitis B vaccine (CLB 3mg) was evaluated in 59 hemodialysis patients and 20 occupational risk personnel. Seroconversion was induced in 52.5% and 70.0% respectively. Twelve months after the first dose, 37.5% of patients and 60.0% of occupational risk personnel had detectable anti-HBs level. Antibody level was expressed in sample ratio units (SRU). Considering only the responders, in the patients group 38.7% had a low anti-HBs response (2.1-9.9 SRU) 32.3% a medium response (10-99.9 SRU) and 29.0% a high response (>100 SRU) while in occupational risk personnel these values were 14.3%, 64.3% and 21.4% respectively. The authors suggest the use of HBV vaccines with more elevated HBsAg concentration or a reinforced immunization schedule to improve the anti-HBs response not only for patients but also for healthy persons.

Immunofluorescent antibody to rotavirus and antigen excretion in infantile acute diarrhoea

A serological study was carried out to evaluate the causal relationship of acute diarrhoea and rotavirus in children under five years of age. The rotaviral infection was demonstrated in paired sera by determining the antibody titers by immunofluorescence test (IF). Bovine rotavirus-infected MA-104 cell culture was used as substratum for IF. Out of 80 paired sera it was shown that 23 (28.75%) presented seroconversion, 19 (23.75%) samples showed a twofold increase in their titers and 38 (47.5%) had no increase in rotavirus antibody. This result is discussed on the light of previously obtained results on viral antigen detection by counterimmunoelectrosmophoresis (CIEOP).

Peroxidase antibody test for mucocutaneous leishmaniasis serology performance indexes and comparison with a fluorescent antibody test: Comparação com o desempenho da reação de imunofluorescência

Performance indexes of the peroxidase antibody test were compared to that of the fluorescent antibody test. The peroxidase antibody test had a statistically higher sensitivity and negative predictive value and a higher efficiency than the fluorescent antibody test but its specificity and positive predictive value were within the 95% confidence limits for the values found for the fluorescent antibody test. Such differences did not change when Chagas' disease and visceral leishmaniasis sera were included in index calculations. Statistical analysis showed that the two tests have a substantial degree of agreement but the immunofluorescent test had a specificity index and a positive predictive value equal to 100.0% when Chagas' disease and visceral leishmaniasis sera were not included in the calculations of the performance index; in this instance, a positive test result equals a disclosure of the disease attribute due to the inexistence of false positive results. The enzyme/ protein ratio of the peroxidase conjugate, resulting in heavy or light-labeled conjugates may pose technical problems to its use in serology tests.

The prevalence of antibody to human parvovirus B19 in Rio de Janeiro, Brazil

During 1985 and 1986 serum samples were collected from the Rio de Janeiro population and examined for the presence of IgG antibody to human parvovirus B19. No difference in prevalence was found between males and females. Antibody prevalence rose from 35% in children less than five years old to almost 80% in children aged eleven to fifteen years. The antibody prevalence in individuals over 50 years old was over 90%.

Enzyme-linked immunosorbent assay (ELISA) for measles antibody: a comparison with haemagglutination inhibition, immunofluorescence and plaque neutralization tests

An enzyme-linked immunosorbent assay (ELISA) for measles antibodies was compared with Plaque Neutralization (PRN), Haemagglutination inhibition (HI) and Fluorescent antibody (IFA) tests in 181 sera from vaccinated children and umbilical cord. Of 179 positive samples by the sensitive PRN, only two, with titers of 8, were negative by ELISA (copositivity of 98.9%). IFA and HI presented, respectively, copo-sitivities of 93.3% and 82.7%. The ELISA presented a high sensitivity as well as a good reproducibility and represents an alternative for the time consuming PRN for detection of low measles antibodies.

Antibody to human T-lymphotropic virus in a patient with Guillain-Barré syndrome (case report)

Serum sample obtained from a male, 12 year old patient suffering from Guillain-Barré syndrome (GBS) was positive for human T-lymphotropic virus (HTLV-I) antibody by the enzyme-linked immunosorbent assay (ELISA) and the Western Blot analysis (WB). Attempts to isolate enteroviruses (including poliovirus) from faecal material in both tissue culture and suckling mice were unsuccessful; in addition, acute and convalescent paired serum samples did not show any evidence of recent poliovirus infection when tested against the three serotypes. Specific tests for detection of Epstein-Barr virus infection were not performed; however, the Paul-Bunnel test yielded negative results. ELISA for detection of anti-cytomegalovirus IgM was also negative. The concomitant occurrence of either adult T cell leukemia (ATL) or lymphoma was not recorded in this case.