Hisato Tada

Effects of Autoantibodies on the Course of Pregnancy and Fetal Growth

Objective To assess the effects of autoantibodies on the course of pregnancy and fetal growth. Methods One thousand one hundred seventy-nine healthy women with singleton gestations were screened in early pregnancy for seven kinds of autoantibodies: antithyroid microsomal antibody, antithyroglobulin antibody, two kinds of rheumatoid factor, antinuclear antibody, anti-DNA antibody, and antimitochondrial antibody. Results In 228 cases (19.3%), at least one autoantibody was found; however, overlap of autoantibodies in the same individual was unexpectedly rare, and only two cases were positive for as many as four autoantibodies. A significantly higher rate of spontaneous abortion was observed in antibody-positive subjects, especially those with antithyroid microsomal (10.4%) or antinuclear antibodies (16.0%), compared with all antibody-negative subjects (5.5%). There were no significant differences in any outcome assessed among subjects positive for antithyroglobulin antibody, anti-DNA antibody, or antimitochondrial antibody compared with all antibody-negative subjects. None of the seven autoantibodies affected the rates of preterm delivery, stillbirth, pregnancy-induced hypertension, malformation, or gender ratio. Conclusion Antithyroid microsomal antibody and antinuclear antibody are the only autoantibodies that increase the abortion rate.

Changes in cytokine production during and after normal pregnancy

PROBLEM: The systemic T helper 1/T helper 2 (Th1/Th2) cytokine balance during normal human pregnancy is controversial, and observations about the balance in the postpartum period have only been reported for up to 3 months.
 METHOD: Whole‐blood, from 83 healthy pregnant women, 80 healthy postpartum women, and 31 healthy non‐pregnant women was stimulated with phorbol 12‐myristate 13‐acetate (PMA) and ionomycin, and the levels of cytokines in the supernatant were measured by enzyme‐linked immunosorbent assay (ELISA).
 RESULTS: The production of all measured cytokines decreased during pregnancy, especially in the second trimester. After delivery, interferon‐Γ (IFN‐Γ) and interleukin‐2 (IL‐2) increased from 2 to 11 months postpartum, and IL‐4 increased from 6 to 11 months postpartum.
 CONCLUSIONS: These data indicate that 1) decreases in production of both Th1‐ and Th2‐type cytokines during pregnancy may be related to the pregnancy‐induced amelioration of autoimmune diseases; 2) increases in production of both Th1‐ and Th2‐type cytokines in the postpartum period may be related to the postpartum aggravation of autoimmune diseases.

Risk of arterial thrombosis in patients with anticardiolipin antibodies and lupus anticoagulant

The relationship between arterial or venous thrombosis and the levels of anticardiolipin antibodies (aCL) and/or existence of lupus anticoagulant (LA) was studied. The 141 patients with systemic lupus erythematosus (SLE) were divided into four groups: aCL single positive (25 cases), LA single positive (11 cases), aCL and LA double positive (25 cases), aCL and LA double negative (80 cases). The prevalence of thrombosis was higher in aCL and LA double positive patients (21/25 cases, 84.0%, P < 0.01) than that in aCL single positive patients (4/25 cases, 16.0%), LA single positive patients (1/11 cases, 9.1%) and double negative patients (3/80 cases, 3.8%). Furthermore, in these double positive patients, all patients (10/10 cases) with a high positive level of aCL (>10 units/ml) had arterial thrombosis, whereas only 2/15 patients (13.3%) with a low positive level of aCL (3–10 units/ml) were affected. Venous thrombosis was frequently found in the low positive group (9/15 cases, 60.0%). On the contrary, none of 105 LA negative patients had arterial thrombosis and only seven (6.7%) had venous thrombosis. These findings indicate that a high aCL activity combined with a LA positive result might be a risk factor for arterial thrombosis.

Prediction of postpartum onset of rheumatoid arthritis

OBJECTIVE To investigate the prediction of the postpartum onset of rheumatoid arthritis (RA). METHODS Two thousand five hundred and forty seven healthy pregnant subjects were examined prospectively and the relation between serum rheumatoid factors (RF) and postpartum onset of RA was observed. Rheumatoid factors were measured in early pregnancy by the antihuman IgG latex agglutination test (Latex test) and antirabbit IgG haemagglutination test (RAHA test). RESULTS Latex test and RAHA test were positive in 26 (1.0%) and 64 (2.5%) pregnant subjects, respectively. Four hundred and ten subjects of 2547 pregnant women could be followed up for one year after delivery. None of 401 subjects without RF, or with only one RF on either Latex test or RAHA test, developed RA after delivery. Two (22.2%) of nine subjects with both RFs developed RA at one and three months postpartum, respectively. Transient arthralgia was found within 12 months postpartum in three of nine (33.3%) subjects with both RFs and this prevalence was significantly higher than that in RF negative subjects (8.1%). CONCLUSION Postpartum onset of RA was found in at least 2 of 2547 healthy subjects (0.08%) and onset was predicted by positive test for rheumatoid factors.

Study on an antibody against F1F2 fragment of human factor V in a patient with Hashimoto's disease and bullous pemphigoid

We found a 81-year-old man with Hashimotos disease and bullous pemphigoid whose activated partial thromboplastin time (APTT) and prothrombin time (PT) were prolonged. Mixing studies with normal plasma failed to correct APTT and PT, suggesting the presence of circulating inhibitor. The patients factor V activity was 11% of normal control and was not corrected by mixing with normal plasma, indicating the presence of an inhibitor against factor V. This inhibitory activity was observed up to 32 times dilution of the patients plasma. The inhibitor activity against factor V was not detected in the fraction of the patients plasma that passed through Protein A Sepharose, but detected in the elution with glycine-HCl buffer. Furthermore, using SDS-PAGE and immunoblotting method, purified IgG from the patients plasma reacted with a protein with molecular weight (74KD) equivalent to F1F2 of factor Va which was activated by thrombin. The inhibitory activity was associated with IgG4 subclass. These data indicate that the inhibitor was IgG antibody which inhibit F1F2 of factor V. Autoimmune mechanism was strongly suggested for the development of the antibody.

High prevalence of thrombocytopenia in SLE patients with a high level of anticardiolipin antibodies combined with lupus anticoagulant

The relationship between thrombocytopenia and the level of anticardiolipin antibodies (aCL) and/or the existence of lupus anticoagulant (LA) ware studied in 146 patients with systemic lupus erythematosus (SLE). These patients were divided into six groups: A, those LA positive with a high level of aCL (>10 U/ml) (10 cases); B, those LA positive with a low level of aCL (3–10 U/ml) (15 cases); C, those LA positive but aCL negative (<3 U/ml) (12 cases); D, LA negatives with a high level of aCL (12 cases); E, LA negatives with a low level of aCL (16 cases); and F, aCL and LA double negatives (81 cases). The prevalence of thrombocytopenia (platelet count ≦ 100 × 109/L) was by far the highest in group A (9/10 cases, 90.0%, P < 0.005, Fishers exact probability test) as compared with group B (4/15 cases, 26.7%), group C (4/12 cases, 33.3%), group D (1/12 cases, 8.3%), group E (4/16 cases, 25.5%), and group F (9/81 cases, 11.1%).

Characteristics of experimental autoimmune hypophysitis in rats : Major antigens are growth hormone, thyrotropin, and luteinizing hormone in this model

We produced experim entalautoimmune hypophysitis (EAH) in rats and investi gated its characteristics. Female Lewis rats were immunized by two injections with homologous pituitary homogenate and complete Freund’s adjuvant. Blood was coll ected seri ally from the rats, and serum antibodies to pituitary antigens were examined . The rats were sacrificed 2 or 4 weeks after the final immunization, and hi stological examinations of the endocrineorgans were carried out. Hi stolog ical examination revealedslight , focal infiltration of mononuclearcells in the pituitary gland only in the rats immunized with the pituitary homogenate. Infiltration of mononuclearcells was not observed in the thyroidgland , pancreas, adrenal gland , or ovary. In the serological examination, antibodies to bothcytoso licantigens and cytoplas micparticle a nti gens from the pituitaryg land were detected by enzyme- linked immunosorbent assay (ELISA), and these antibody levels increased with time. We stern blottingusing the sennn antibodiesidentified an immunoreactive protein of -2 1.5 k.Daamo ng these antigens, and we confirmed that this protein was ratgrow thhormone (GH). Furth ermore, antibodies to GH, thyrotropin (TSH), and luteinizing hormone (LH) were detected by E LISA. Antibodies to folli cule stimulating horm one, prol actin , or adrenocorticotropin were not detected . These data suggest that several antigens from the pituitary gland are involved in EAH inrats, and that GH, TSH, and LH are major antigens among the pituitary antigens in this model.

Blocking‐type anti‐TSH receptor antibodies and relation to responsiveness to antithyroid drug therapy and remission in Graves’ disease

objective Antithyroid drugs are effective in some patients with Graves’ disease but not in others. The factors responsible for this difference are still unknown. We examined the relationship between the nature of anti‐TSH receptor (TSH‐R) antibodies and responsiveness to drugs in Graves’ disease.

Development of liver dysfunction after delivery is possibly due to postpartum autoimmune hepatitis. A report of three cases

Autoimmune diseases, especially autoimmune thyroid disease, frequently develop after delivery due to the immune rebound mechanism. Most cases involve transient dysfunction of affected organs. Weexamined three patients who developed liver dysfunction after delivery. They were all diagnosed with definite or probable autoimmune hepatitis using the scoring system of the International Autoimmune Hepatitis Group. Moreover, all of them had anti‐CYP2D6 antibodies detected by a sensitive radioligand assay. Our findings strongly suggest that liver dysfunction is induced by postpartum autoimmune hepatitis, and clinicians should be aware of this disease.

Anti-CYP2D6 antibodies detected by quantitative radioligand assay and relation to antibodies to liver-specific arginase in patients with autoimmune hepatitis.

BACKGROUND Antibodies to cytochrome P4502D6 (CYP2D6) were measured and their prevalence compared with that of antibodies to liver-specific arginase in patients with autoimmune hepatitis (AIH). METHODS Anti-CYP2D6 antibodies were measured by sensitive radioligand assay and enzyme-linked immunosorbent assay (ELISA), and anti-arginase antibodies were measured by ELISA in 132 patients (definite AIH 11, probable AIH 36, hepatitis C 20, hepatitis B 23, other autoimmune diseases 42) and 50 healthy controls. RESULTS CYP2D6 index (radioligand assay) was significantly higher in all groups of patients than those in healthy controls. A higher index than the cut-off value (mean+3 S.D. in healthy controls) was found in 36.4%, 44.4%, 25.0%, 17.4% and 28.6% of patients with definite AIH, probable AIH, hepatitis C, hepatitis B and other autoimmune diseases, respectively. CYP2D6 index was not related to serum IgG, anti-nuclear antibody or AIH scores, and was weakly correlated with anti-arginase antibody activity. When CYP2D6 index and anti-arginase antibodies were combined, 55.3% of AIH patients were positive for either one or both antibodies. CONCLUSIONS Anti-CYP2D6 antibodies by radioligand assay were frequently present in patients with AIH. Combined tests for anti-CYP2D6 radioligand assay and anti-arginase antibodies resulted in detection of 55% of AIH patients.