Presence of Autoantibodies to Gastric Parietal Cells and Subsequent Vitamin B12 Deficiency in Rheumatoid Arthritis Patients
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 125
- 试验地点
- 1
- 主要终点
- Prevalence of Vitamin B12 Deficiency
研究概览
简要总结
A review of the literature reveals that very few studies have assessed the potential co-existence of vitamin B12 deficiency due to gastric parietal cell autoantibodies. While Segal et al. in 2004 published a study which found that 49% of patients with RA had vitamin B12 deficiency, no assessment of the etiology or the presence of autoantibodies was made. While Goeldner et al. in 2011 and Datta et al. in 1990 demonstrated that anti-gastric parietal cell antibodies (anti-GPC Ab) were found in <5% to 28% of RA patients respectively, no additional testing was implemented to determine the significance, specifically whether or not the presence of anti-GPC Ab related to vitamin B12 deficiency.
The purpose of this study is to determine the prevalence and metabolic significance of anti-GPC Ab in three cohorts: (1) a group of patients with Rheumatoid Arthritis, (2) a group of patients with autoimmune thyroid disease (AITD), and (3) a group of patients with neither RA or AITD. To determine the significance of the presence of anti-GPC Ab, testing of the current serum B12 level along with a metabolite dependent on adequate vitamin B12 levels (Methylmalonic acid) will be tested.
详细描述
Background: Organ specific antibodies such as anti-gastric parietal cell antibodies (anti-GPC Ab) have been found in a variable number of patients with RA, but it is unclear what significance these antibodies have on actual vitamin B12 levels. Patients with RA have been found to have vitamin B12 deficiency up to near 50% but it is unclear if this deficiency is due to anti-GPC Ab.
Hypothesis
By virtue of the aberrant autoimmune process that occurs in RA, patients with RA are more likely to have anti-GPC Ab and more likely than a control arm or participants with autoimmune thyroid disease (AITD) to have vitamin B12 deficiency.
Method: 135 patients will be consented; 45 to the RA arm, 45 to an AITD arm, and 45 to a control arm. Exclusion criteria will filter patients who would have other reasons for altered vitamin B12 absorption, such as inflammatory bowel disease, surgery, or medication use. After obtaining consent subjects will be sent to lab a serum anti-GPC Ab test (obtainable in an SLE panel), RF, B12/folate (as available for ordering in CHCS), methyl malonic acid, and (for the control arm subjects and AITD subjects) an anti-CCP IgG. Patients will also complete a one-sided, one page questionnaire asking them about dietary and medication exposures.
Outcomes: (1) Determine whether evidence of serum vitamin B12 deficiency, as measure by either a low vitamin B12 level or elevated methylmalonic acid, will be more common in RA patients with anti-GPC Ab. (2) Determine the prevalence of anti-GPC Ab in a group of patients with RA as compared to a group of patients with AITD and with no known systemic or organ specific autoimmune condition.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Control
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adult, age 18 and older
- •RA arm: History of Rheumatoid Arthritis
- •AITD arm: History of an autoimmune thyroid disease without a history or clinically obvious manifestation of an organ specific or systemic autoimmune process.
- •Control arm: No history of RA and no history or clinically obvious manifestation of an organ specific or systemic autoimmune process.
排除标准
- •Known vitamin B12 deficiency for which the participant was formerly treated or continues to receive therapy.
- •Active malabsorptive state to include but not limited to celiac disease, inflammatory bowel disease, etc.
- •Surgically induced malabsorptive state to include but not limited to Roux-en-Y Gastric bypass
- •Use of medications that may interfere with vitamin B12 absorption
- •Patients with a thyroid condition not consistent with an autoantibody process (i.e. congenital absence of the thyroid, infectious thyroiditis, thyroidectomy for non-autoimmune process, toxic multinodular goiter) will be excluded from the autoimmune thyroid arm.
结局指标
主要结局
Prevalence of Vitamin B12 Deficiency
时间窗: 7 months
Hypothesis: Evidence of serum vitamin B12 deficiency, as measure by either a low vitamin B12 level or elevated methylmalonic acid, will be more common in RA patients with anti-GPC Ab.
次要结局
- Presence of Anti-GPC Antibodies(7 months)
研究者
Matthew B. Carroll, LtCol, USAF, MC, FACP, FACR
Chief of Rheumatology
Keesler Air Force Base Medical Center