Elevated IgA antiphospholipid antibodies in healthy pregnant women in Sudan but not Sweden, without corresponding increase in IgA anti-ß2 glycoprotein I domain 1 antibodies.

OBJECTIVE: The role of antiphospholipid antibodies (aPL) during apparently normal pregnancy is still unclear. IgA aPL are prevalent in populations of African origin. Our aim was to measure all isotypes of anticardiolipin (anti-CL) and anti-ß2 glycoprotein I (anti-ß2GPI) in healthy pregnant and non-pregnant women of different ethnicities. METHODS: Healthy Sudanese pregnant women (n = 165; 53 sampled shortly after delivery), 96 age-matched Sudanese female controls and 42 healthy pregnant and 249 non-pregnant Swedish women were included. IgA/G/M anti-CL and anti-ß2GPI were tested at one time point only with two independent assays in Sudanese and serially in pregnant Swedes. IgA anti-ß2GPI domain 1 and as controls IgA/G/M rheumatoid factor (RF), IgG anti-cyclic citrullinated peptide 2 (anti-CCP2) and anti-thyroid peroxidase (anti-TPO) were investigated in Sudanese females. RESULTS: Pregnant Sudanese women had significantly higher median levels of IgA anti-CL, IgA anti-ß2GPI (p < 0.0001 for both antibodies using two assays) and IgM anti-ß2GPI (both assays; p < 0.0001 and 0.008) compared with non-pregnant Sudanese. IgA anti-CL and anti-ß2GPI occurrence was increased among Sudanese pregnant women compared with national controls. No corresponding increase during pregnancy was found for IgA anti-ß2GPI domain 1 antibodies. Both IgG anti-CL and IgG control autoantibodies decreased during and directly after pregnancy among Sudanese. Serially followed Swedish women showed no changes in IgA aPL, whereas IgG/M anti-CL decreased. CONCLUSIONS: IgA aPL are increased in Sudanese but not in Swedish women, without corresponding increase in IgA domain 1. Whether due to ethnicity and/or environmental influences the occurrence of IgA aPL during Sudanese pregnancies, and its clinical significance, is yet to be determined.

Pentraxin 3 in serum and synovial fluid of patients with rheumatoid arthritis with and without autoantibodies.

OBJECTIVES: Pentraxin 3 (PTX3) is a locally produced multifunctional protein involved in inflammation, matrix deposition, and immunity. As patients with seropositive rheumatoid arthritis (RA) have a more severe disease course and higher risk of joint destruction than seronegative patients, the aim of the present study was to examine differences in PTX3 in synovial fluid (SF) (and serum) in seropositive compared to seronegative RA, and other local markers of inflammation and destruction. METHOD: Ninety-seven RA patients with knee effusion were included. Serum and SF levels of PTX3, as well as serum levels of anti-citrullinated protein antibody and rheumatoid factor of immunoglobulin A and M subclasses, and markers of inflammation and potential destruction in SF: white blood cell counts, tumour necrosis factor, interleukin-6, vascular endothelial growth factor, metalloproteinase 3, and cartilage oligomeric matrix protein, were analysed. In addition, a radiographic knee examination was performed. RESULTS: Seropositive patients had significantly higher PTX3 levels in SF than seronegative patients, whereas there was no difference for serum levels. SF-PTX3 levels correlated with disease activity and with local inflammatory markers, especially polymorphonuclear cells, and with autoantibody levels. There was no correlation between PTX3 levels in serum and SF. CONCLUSION: The correlation of disease activity and autoantibody levels with SF-PTX3 levels in antibody-positive patients suggests a role for PTX3 in the inflammatory process specifically in seropositive RA joints, and supports the hypothesis that seropositive and seronegative RA are different disease entities. Polymorphonuclear granulocytes may be an important source of PTX3 in RA SF.