Research Article

Usefulness of Soluble Transferrin Receptor in the Diagnosis of Iron Deficiency Anemia in Rheumatoid Arthritis Patients in Clinical Practice

Table 1

Characteristics of patients under study. Data are given as . Ranges are given in brackets and percentages in parentheses.

Number116
Age, yr [29–92]
Women/men57/57 (50/50)
Hb (g/dl), women [8.9–11.9]
Hb (g/dl), men [8.6–13.8]
Creatinine, mg/dl [0.47-2.34]
Autoantibodies
 Without any53 (46)
 RF60 (52)
 ACPA58 (50)
 RF and ACPA54 (47)
Classification of anemia
 IDA6 (5)
 ACD60 (52)
 IDA/ACD36 (31)
 Other anemia14 (12)
Indicators of disease activity
 CRP, mg/l [0.1-269.3]
 ESR, mm/hour46.6 (±31.0) [2–120]
 DAS28 score4.6 (±1.6) [0.8–9.2]
Indicators of iron status
 MCV, μm388.0 (±6.1) [73–107]
 MCH, pg29.3 (±3.4) [23–35]
 Ferritin, ng/ml266.2 (±300.1) [10–1272]
 Iron, μg/dl49.1 (±25.7) [10–118]
 Transferrin g/l1.3 (±0.6) [1.4–3.8]
 TSAT, %15.8 (±8.5) [2.9–62.2]
 sTfR, mg/l4.4 (±2.0) [2.2–13.6]
Immunosuppressive therapy
 None29 (25.0)
 Prednisolone mono low dose (≤7.5 mg/die)26 (22.4)
 csDMARD41 (35.3)
 bDMARD/tsDMARD20 (17.2)
 Anti-TNF5 (4.3)
 Abatacept3 (2.6)
 RTX6 (5.2)
 Anti-Il-64 (3.4)
 JAK-I2 (1.7)
Comorbidities
 Arterial hypertension71 (61.2)
 Cardiovascular disease (coronary heart disease, peripheral arterial disease, heart failure, and state after cerebral ischemia)28 (24.1)
 Absolute arrhythmia20 (17.2)
 Chronic renal insufficiency13 (12.1)
 Asthma4 (3.4)
 COPD3 (2.6)
 Hyperlipidemia13 (12.1)
 Diabetes mellitus type 220 (17.2)

Abbreviations: SD: standard deviation; Hb: hemoglobin; RF: rheumatoid factor; ACPA: anticitrullinated peptide antibody; IDA: iron deficiency anemia; ACD: anemia of chronic disease; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; DAS28: disease activity score in 28 joints; MCV: mean corpuscular volume; MCH: mean corpuscular hemoglobin; sTfR: soluble transferrin receptor; csDMARDs: conventional synthetic disease-modifying antirheumatic drugs; bDMARD: biologic disease-modifying antirheumatic drugs; tsDMARD: targeted synthetic disease-modifying antirheumatic drugs; RTX: rituximab; anti-Il-6: anti-interleukin-6 antibody; JAK-I: janus kinase inhibitor; COPD: chronic obstructive pulmonary disease.