Table 3. Comparison of clinical characteristics of IIP patients with and without thyroid antibodies.
| Variable | Total IIP | IPF | Non-IPF | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| TgAb and/or TPOAb positive | TgAb and TPOAb negative | P value | TgAb and/or TPOAb positive | TgAb and TPOAb negative | P value | TgAb and/or TPOAb positive | TgAb and TPOAb negative | P value | |||
| Subjects (n) | 22 | 78 | 5 | 25 | 17 | 53 | |||||
| Age (years) | 69.9±2.2 | 70.7±1.0 | 0.603 | 70.6±2.7 | 70.3±1.4 | 0.957 | 69.7±2.8 | 70.8±1.4 | 0.612 | ||
| Gender (M/F) | 18/4 | 54/24 | 0.293 | 5/0 | 21/4 | 1.000 | 13/4 | 33/20 | 0.383 | ||
| Smoker (+/−) | 15/7 | 53/25 | 1.000 | 5/0 | 20/5 | 0.556 | 10/7 | 33/20 | 1.000 | ||
| Brinkman index | 729±168 | 567±63 | 0.615 | 954±232 | 695±118 | 0.275 | 663±207 | 506±74 | 0.899 | ||
| Autoantibodies* (+/−) | 15/7 | 35/43 | 0.090 | 3/2 | 12/13 | 1.000 | 12/5 | 23/30 | 0.093 | ||
| Corticosteroid (+/−) | 2/20 | 26/52 | 0.031 | 1/4 | 8/17 | 1.000 | 1/16 | 18/35 | 0.028 | ||
| Duration of corticosteroid treatment (days) | 30±29 | 405±89 | 0.019 | 126±126 | 304±128 | 0.706 | 2±2 | 452±116 | 0.019 | ||
| Immunosuppressive reagents (+/−) | 0/22 | 12/66 | 0.063 | 0/5 | 4/21 | 1.000 | 0/17 | 8/45 | 0.185 | ||
| Duration of Immunosuppressive reagent treatment (days) | NA | 191±79 | NA | NA | 139±111 | NA | NA | 215±104 | NA | ||
| NAC (+/−) | 2/20 | 9/69 | 1.000 | 2/3 | 5/20 | 1.565 | 0/17 | 4/49 | 0.566 | ||
| Duration of NAC treatment (days) | 143±108 | 113±48 | 0.783 | 627±442 | 89±48 | 0.385 | NA | 125±66 | 0.247 | ||
| Raynaud’s phenomenon (+/−) | 3/19 | 1/77 | 0.032 | 1/4 | 0/25 | 0.167 | 2/15 | 1/52 | 0.144 | ||
| Arthralgia (+/−) | 3/19 | 6/72 | 0.408 | 1/4 | 2/23 | 0.433 | 2/15 | 4/49 | 0.628 | ||
| Morning stiffness (+/−) | 3/19 | 5/73 | 0.369 | 0/5 | 2/23 | 1.000 | 3/14 | 3/50 | 0.149 | ||
| Dry mouth/eye (+/−) | 4/18 | 18/60 | 0.775 | 0/5 | 4/21 | 1.000 | 4/13 | 14/39 | 1.000 | ||
| Rash (+/−) | 0/22 | 5/73 | 0.583 | 0/5 | 1/24 | 1.000 | 0/17 | 4/49 | 0.566 | ||
| Muscle weakness (+/−) | 3/19 | 1/77 | 0.032 | 0/5 | 0/25 | 1.000 | 3/14 | 1/52 | 0.042 | ||
| WBC (/μL) | 7,409±453 | 7,943±343 | 0.742 | 7,040±520 | 8,496±641 | 0.229 | 7,518±570 | 7,683±404 | 0.681 | ||
| LDH (IU/L) | 260±22 | 248±8 | 0.547 | 222±15 | 249±12 | 0.385 | 271±27 | 247±11 | 0.253 | ||
| CK (U/L) | 182±51 | 100±11 | 0.045 | 81±17 | 102±28 | 0.872 | 211±65 | 99±9 | 0.036 | ||
| CRP (mg/dL) | 0.56±0.29 | 0.62±0.17 | 0.575 | 1.41±1.29 | 0.48±0.13 | 0.627 | 0.31±0.109 | 0.68±0.24 | 0.764 | ||
| ESR (mm/h) | 20±4 | 15±1 | 0.443 | 19±10 | 14±2 | 0.706 | 20±4 | 16±2 | 0.471 | ||
| ALD (U/L) | 7.7±1.7 | 5.5±0.2 | 0.241 | 6.4±1.8 | 5.9±0.4 | 0.737 | 8.0±2.1 | 5.2±0.3 | 0.086 | ||
| BNP (pg/mL) | 75.9±35.6 | 42.8±8.1 | 0.450 | 39.5±23.1 | 30.1±5.7 | 0.811 | 87.1±46.1 | 51.5±12.9 | 0.483 | ||
| KL-6 (U/mL) | 1,152±192 | 1,114±93 | 0.787 | 1,115±180 | 1,139±115 | 0.829 | 1,163±245 | 1,102±126 | 0.758 | ||
| SP-A (ng/mL) | 77.4±7.8 | 73.6±5.0 | 0.336 | 88.3±23.2 | 74.3±6.8 | 0.482 | 73.8±7.4 | 73.2±6.6 | 0.408 | ||
| SP-D (ng/mL) | 237.5±40.5 | 226.5±17.2 | 0.687 | 268.4±89.5 | 244.0±21.5 | 0.933 | 227.9±46.7 | 218.5±23.0 | 0.943 | ||
| VC (L) | 2.8±0.2 | 2.6±0.1 | 0.448 | 2.9±0.3 | 2.6±0.2 | 0.314 | 2.7±0.3 | 2.6±0.1 | 0.698 | ||
| %VC (%) | 82.2±4.9 | 82.1±2.6 | 0.965 | 85.6±5.5 | 78.8±4.5 | 0.739 | 81.0±6.5 | 83.8±3.3 | 0.784 | ||
| TSH (μIU/mL) | 3.39±0.83 | 2.36±0.31 | 0.083 | 2.11±0.50 | 2.97±0.90 | 0.957 | 3.76±1.06 | 2.08±0.18 | 0.057 | ||
| FT4 (ng/dL) | 1.16±0.04 | 1.17±0.02 | 0.835 | 1.13±0.07 | 1.18±0.04 | 0.666 | 1.17±0.05 | 1.16±0.02 | 0.875 | ||
| FT3 (pg/mL) | 2.86±0.09 | 2.84±0.05 | 0.937 | 2.78±0.24 | 2.98±0.06 | 0.552 | 2.89±0.10 | 2.77±0.07 | 0.617 | ||
| TgAb (IU/mL) | 225.93±45.83 | 6.28±0.92 | <0.001 | 235.08±107.16 | 3.96±1.43 | <0.001 | 223.24±52.17 | 7.39±1.16 | <0.001 | ||
| TPOAb (IU/mL) | 131.33±38.69 | 7.29±0.58 | <0.001 | 138.53±115.83 | 5.76±1.13 | 0.074 | 129.21±39.44 | 8.01±0.66 | <0.001 | ||
*, anti-nuclear antibody, rheumatoid factor, anti-double stranded DNA antibody, anti-SSA antibody, anti-SSB antibody, anti-U1 ribonucleoprotein antibody, anti-cyclic citrullinated peptide antibody, anti-topoisomerase antibody, anti-smith antibody, anti-aminoacyl tRNA synthetase antibody, anti-centromere antibody, myeloperoxidase-anti-neutrophil cytoplasmic antibody, proteinase 3-anti-neutrophil cytoplasmic antibody. Mean ± SEM. +, positive; −, negative. NA, not applicable; IPF, idiopathic pulmonary fibrosis; NAC, inhalation of N-acetylcysteine; WBC, white blood cell; LDH, lactate dehydrogenase; CK, creatine kinase; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; ALD, aldolase; BNP, brain natriuretic peptide; KL-6, Krebs von den lungen-6; SP-A, surfactant protein-A; SP-D, surfactant protein-D; VC, vital capacity; TSH, thyroid stimulating hormone; FT4, free thyroxine; FT3, free triiodothyronine; TgAb, thyroglobulin antibody; TPOAb, thyroid peroxidase antibody.