Palladium-based dental alloys are associated with oral disease and palladium-induced immune responses.

BACKGROUND: Palladium (Pd) and gold (Au) based dental alloys have been associated with oral disease. OBJECTIVES: This study was designed to explore possible associations between the presence of Au-based and Pd-based dental alloys, and oral lesions, systemic complaints, and specific in vivo and in vitro immune responses. METHODS: The investigated population consisted of three groups: 26 non-metal-allergic volunteers, 25 metal-allergic patients, and 20 oral disease patients. Medical histories were taken, oral examinations were carried out, and compositions of all dental alloys were determined. Then, Au and Pd patch tests and in vitro assays were performed, revealing cytokine production by peripheral blood mononuclear cells [T helper (Th)1, interferon-γ; Th2, interleukin (IL)-5 and IL-13] and lymphocyte proliferation (LTT-MELISA(®) ). RESULTS: Non-plaque-related gingivitis was associated with the presence of Pd-based dental alloys, and Pd-positive patch tests and in vitro assays. Collectively, participants with Pd-based dental alloys showed increased Pd patch test reactivity (p < 0.05) and lymphoproliferation (p < 0.05). In contrast, oral lichenoid lesions were associated with Au-based alloys (p < 0.05), but this was not reflected by Au-specific immunoreactivity. CONCLUSIONS: Oral lesions and Pd-induced immune responses are associated with the presence of dental alloys. However, most oral disease patients did not show positive patch test results or in vitro signs of specific immunoreactivity, suggesting local toxic reactions or the involvement of innate immune responses.

Type 1 diabetes and celiac disease in adults: glycemic control and diabetic complications.

The prevalence of celiac disease (CD) in patients with type 1 diabetes mellitus (T1DM) is 4.5 %. Objective of the study is to investigate (1) the course of glycemic control at CD diagnosis and after the initiation of a gluten-free diet (GFD) in T1DM patients; (2) the prevalence of diabetic complications in T1DM patients with adult onset of CD. In 20 hospitals in the Netherlands, we identified T1DM patients diagnosed with CD at adult age. We retrospectively collected glycated hemoglobin (HbA1c) levels before CD diagnosis, at CD diagnosis, and the most recent HbA1c levels as well as the presence of nephropathy and retinopathy. The control group consisted of patients with T1DM and negative CD serology matched for age, gender, T1DM duration, and HbA1c levels. Thirty-one patients were eligible with a median duration of T1DM and CD of 27 years (IQR 14-37) and 3 years (IQR 1-8), respectively. The matched control group consisted of 46 patients. HbA1c levels at the moment of CD diagnosis were 7.5 % (IQR 7.1-8) [58 mmol/mol] and at the most recent visit 7.4 % (IQR 6.9-7.9, P = 0.15) [57 mmol/mol] indicating no difference. Prevalence of retinopathy was lower in T1DM + CD group compared with controls, (38.7 vs 67.4 %, P < 0.05), whereas no difference in the prevalence of nephropathy was found between the groups (P = 0.09). In conclusion, T1DM + CD patients have less retinopathy compared to T1DM patients without CD. A GFD possibly favorable affects the development of vascular complications in T1DM patients.

Sodium tetrachloropalladate for diagnosing palladium sensitization.

BACKGROUND: Exposure to palladium (Pd) may lead to clinical allergic reactions. With frequent nickel (Ni) exposure and cross-reactivity between Ni and Pd at the T cell recognition level, positive Pd reactions on patch testing are surprisingly uncommon. PdCl(2) is often used for epicutaneous patch testing. OBJECTIVES: To compare the sensitivity and specificity of sodium tetrachloropalladate (Na(2) PdCl(4)) and PdCl(2) for Pd patch testing in metal-allergic patients and non-allergic controls. METHODS: Twenty-six metal-allergic patients and 26 non-allergic controls were selected on the basis of detailed medical histories. Patch test results were used to determine the diagnostic performance of the two Pd salts as compared with NiSO(4). RESULTS: With three outliers in both groups, the sensitivity/specificity were calculated to be 42%/96% for PdCl(2), 65%/92% for Na(2) PdCl(4) , and 77%/92% for NiSO(4). Furthermore, of all (n = 19) Na(2) PdCl(4) reactors, 17 (89%) also showed positive reactions to NiSO(4). Conversely, of all (n = 22) NiSO(4) reactors, 17 (77%) showed concomitant positive reactions to Na(2) PdCl(4) . CONCLUSIONS: Positive test reactions to Na(2) PdCl(4) are confirmed by large-scale concordant reactions to PdCl(2) and NiSO(4). Although statistical significance was not reached, the increased sensitivity has important clinical relevance, as false-positive results are rare. Incorporation of Na(2) PdCl(4) into standard and/or dental screening patch test series is suggested.

Gluten tolerance in adult patients with celiac disease 20 years after diagnosis?

BACKGROUND AND OBJECTIVE: Celiac disease (CD) is believed to be a permanent intolerance to gluten. A number of patients, however, discontinue the gluten-free diet (GFD) without developing symptoms or signs. The aim of our study was to investigate whether CD patients are capable of developing tolerance to gluten. METHODS: All 77 adult patients from our hospital known to have biopsy-proven CD for more than 10 years were invited to participate. We investigated symptoms, gluten consumption, antibodies for CD and other autoimmunity, human leukocyte antigen (HLA)-typing, bone mineral density, and performed small bowel biopsies. Tolerance was defined as no immunological or histological signs of CD while consuming gluten. RESULTS: Sixty-six patients accepted participation, but after review of the diagnostic biopsies 53 were found to have true CD. Twenty-three percent of patients had a gluten-containing diet, 15% admitted gluten transgression and 62% followed the GFD. Patients on a GFD had significantly more osteoporosis. Normal small bowel mucosa was found in four of eight on gluten-containing diet and in four of four with gluten transgression. Two patients were considered to have developed tolerance to gluten. One of them was HLA-DQ2/DQ8 negative. CONCLUSION: Development of tolerance to gluten seems possible in some patients with CD. Further follow-up will show whether this tolerance is permanent or only a long-term return to latency. This feature may be associated with genetic characteristics, especially with HLA genotypes that differ from DQ2 or DQ8. More insight into the mechanisms of the development of gluten tolerance may help to distinguish those CD patients that might not require life-long GFD.

CD4(+)CD25hi regulatory T-cell frequency correlates with persistence of human papillomavirus type 16 and T helper cell responses in patients with cervical intraepithelial neoplasia.

CD4(+)CD25(hi)CTLA4(+)FoxP3(+) regulatory T cells (Treg) have been shown to maintain immune tolerance against self antigens and increased circulating frequencies have been reported in various types of cancers. Circulating invariant natural killer T-cells (iNKT) are reduced in cancer patients and low iNKT frequency is related to poor prognosis. It is not yet clear whether high Treg numbers and low iNKT cell numbers pose an increased risk for the progression of premalignant lesions or whether Treg and iNKT cell numbers are influenced by dysplasia. We therefore studied prospectively the relation between iNKT cell and Treg frequencies and the natural course of human papillomavirus type 16 (HPV16) induced pre-malignant cervical dysplasia in 82 patients who participated in a nonintervention cohort study of women with abnormal cytology. Treg frequencies were significantly increased in women who had persistent HPV16 infection. Within the HPV16 persistence group there was no difference in Treg frequencies among patients who developed a CIN3 lesion and patients who did not progress to CIN3. Furthermore, Treg frequencies were increased in patients who had detectable HPV16 E7 specific IL-2 producing T-helper cells, which suggests a causal role of HPV infection in Treg development in parallel with HPV16 specific T helper cells. No evidence was found for a role for iNKT cells in persistence of HPV16 and progression of HPV16 induced CIN lesions. However, HPV-persistence-associated Tregs may explain the inefficacy of concomitant persistence associated immunity and may contribute to subsequent progression to neoplasia.