Antigliadin immunoglobulin A best in finding celiac disease in children younger than 18 months of age.

OBJECTIVES: The aim was to investigate age-dependent serum levels and occurrence of elevated celiac disease (CD)-related antibodies in young children, to define the optimal serological procedure when selecting for small intestinal biopsy. PATIENTS AND METHODS: Included were 428 children with biopsy verified CD (median age 16 months; range 7.5 months-14 years) and 216 controls (median age 2.7 years; range 8.5 months-14.6 years). Immunoglobulin (Ig) A antibodies against gliadin (AGA-IgA), tissue transglutaminase (tTG-IgA), and endomysium (EMA-IgA) were analysed. RESULTS: Increased serum AGA-IgA levels were found in 411 of 428 CD cases, tTG-IgA in 385 of 428, and EMA-IgA in 383 of 428. In the control group, 11 of 216 had increased levels of AGA-IgA, 5 of 216 of tTG-IgA, and 8 of 216 of EMA-IgA. In CD children younger than 18 months, elevated AGA-IgA occurred in 97% and elevated tTG-IgA and EMA-IgA were found in 83% of the cases. Conversely, in CD children older than 18 months, elevated AGA-IgA occurred in 94%, and elevated tTG-IgA and EMA-IgA were found in 99% of the cases. CONCLUSIONS: In children older than 18 months, both tTG-IgA and EMA-IgA are sufficiently accurate to be used as a single antibody marker, whereas a large proportion of younger children with CD lack these antibodies. Therefore, when selecting children for small intestinal biopsy, the detection of a combination of AGA-IgA and tTG-IgA is optimal for identifying untreated CD in children younger than 18 months.

Antibodies against mutated citrullinated vimentin are a better predictor of disease activity at 24 months in early rheumatoid arthritis than antibodies against cyclic citrullinated peptides.

OBJECTIVE: To evaluate the predictive values for disease progression of various antibodies against citrullinated peptide proteins (ACPA) and their relation to PTPN22 1858C/T polymorphism and HLA-DRB1 alleles in early rheumatoid arthritis (RA). METHODS: The ACPA, e.g., antibodies against mutated citrullinated vimentin (MCV), cyclic citrullinated peptides (CCP) type 2 and 3 (both of IgG isotype) and 3.1 (of both IgG and IgA isotypes), were analyzed at baseline in patients with early RA (n = 210) and in population controls (n = 102) using an enzyme immunoassay. A receiver-operating characteristic curve was constructed for each antibody. Disease activity [swollen and tender joints, visual analog scale for global health, and erythrocyte sedimentation rate (ESR)] was evaluated at baseline and regularly for 24 months. Radiographs of hands and feet were graded using the Larsen score. RESULTS: Patients with anti-MCV antibodies had significantly less reduction in Disease Activity Score (DAS28) over time (p < 0.01), and significantly increased area under the curve (AUC) for DAS28 (p < 0.05), ESR (p < 0.01), C-reactive protein (p < 0.01), and swollen joint count (p = 0.057) compared to those without. Corresponding differences were not found in patients with anti-CCP2, CCP3, and CCP3.1 antibodies. Radiological progression (p < 0.0001-0.01) and radiological outcome (p < 0.0001-0.01) at 24 months were significantly predicted by all ACPA after baseline adjustments. PTPN22 T variant and HLA-DRB1 alleles were not related to radiological progression or inflammatory activity over time. CONCLUSION: Anti-MCV antibodies are associated with a more severe RA disease, as measured by DAS28, ESR, and swollen joint count over time, compared with anti-CCP2, CCP3, and CCP3.1 antibodies. Radiological progression was predicted equally by all 4 autoantibodies.

The PTPN22 1858C/T polymorphism is associated with anti-cyclic citrullinated peptide antibody-positive early rheumatoid arthritis in northern Sweden.

The PTPN22 1858C/T polymorphism has been associated with several autoimmune diseases including rheumatoid arthritis (RA). We have shown that carriage of the T variant (CT or TT) of PTPN22 in combination with anti-cyclic citrullinated peptide (anti-CCP) antibodies highly increases the odds ratio for developing RA. In the present study we analysed the association between the PTPN22 1858C/T polymorphism and early RA in patients from northern Sweden, related the polymorphism to autoantibodies and the HLA-DR shared epitope, and analysed their association with markers for disease activity and progression. The inception cohort includes individuals who also donated samples before disease onset. A case-control study was performed in patients (n = 505; 342 females and 163 males) with early RA (mean duration of symptoms = 6.3 months) and in population-based matched controls (n = 970) from northern Sweden. Genotyping of the PTPN22 1858C/T polymorphism was performed using a TaqMan instrument. HLA-shared epitope alleles were identified using PCR sequence-specific primers. Anti-CCP2 antibodies were determined using enzyme-linked immunoassays. Disease activity (that is, the number of swollen and tender joints, the global visual analogue scale, and the erythrocyte sedimentation rate) was followed on a regular basis (that is, at baseline and after 6, 12, 18 and 24 months). Both the 1858T allele and the carriage of T were associated with RA (chi2 = 23.84, P = 0.000001, odds ratio = 1.69, 95% confidence interval = 1.36-2.11; and chi2 = 22.68, P = 0.000002, odds ratio = 1.79, 95% confidence interval = 1.40-2.29, respectively). Association of the 1858T variant with RA was confined to seropositive disease. Carriage of 1858T and the presence of anti-CCP antibodies was independently associated with disease onset at an earlier age (P < 0.05 and P < 0.01, respectively), while the combination of both resulted in an even earlier age at onset. Smoking was identified as a risk factor independent of the 1858T variant and anti-CCP antibodies.