Table 1.

Population characteristics for all subjects by case/control status

Individual variablesControls, n (%)Lymphoma cases, n (%)P
Sex
    Male279 (51.3)258 (55.3)
    Female265 (48.7)209 (44.7)0.21
Age (y), mean (SD)58.0 (17.7)60.5 (16.4)0.02
Center
    Barcelona456 (83.8)371 (79.4)
    Madrid49 (9.0)50 (10.7)
    Tarragona39 (7.2)46 (9.9)0.18
Education level
    Low417 (76.7)352 (75.4)
    Medium89 (16.4)71 (15.2)
    High38 (7.0)44 (9.4)0.35
Smoking history
    Never260 (48.0)219 (47.2)
    Ex-smoker144 (26.6)155 (33.4)
    Current138 (25.5)90 (19.4)0.02
Alcohol consumption
    Regular drinker259 (47.7)208 (44.8)
    Nonregular drinker284 (52.3)256 (55.2)0.36
Social class*
    I12 (2.2)19 (4.1)
    II-III74 (13.6)74 (15.9)
    IV-V298 (54.9)257 (55.2)
    Unclassified159 (29.3)116 (25.0)0.14
No. siblings
    Only child24 (4.4)23 (4.9)
    1 sibling88 (16.2)83 (17.8)
    2-3 siblings209 (38.5)160 (34.3)
    >3 siblings223 (40.9)201 (43.0)0.58
Atopy-related conditions
    Treated for asthma49 (9.1)40 (8.6)0.81
    Treated for eczema44 (8.1)60 (12.9)0.01
    Any asthma or eczema89 (16.3)94 (20.2)0.11
Immunoglobulin measures
    Total IgE, mean (GSD)37.6 (4.5)18.4 (5.4)<0.0001
        Tertile 1 (0.00-2.96 kU/L)§177 (33.0)240 (51.5)
        Tertile 2 (2.96-4.18 kU/L)§179 (33.3)129 (27.7)
        Tertile 3 (4.18-7.61 kU/L)§181 (33.7)97 (20.8)<0.0001
    Specific IgE
        Positive specific IgE for ≥1 panels81 (15.5)50 (11.0)0.04
        Positive specific IgE for ≥2 panels15 (3.3)12 (2.9)0.73
    Total IgA, mean (GSD)224.8 (1.7)156.6 (2.4)<0.0001
    Total IgM, mean (GSD)96.06 (1.8)79.76 (2.7)0.003
    Total IgG, mean (GSD)822.80 (1.4)843.64 (1.8)0.41
Lymphoma type
    All lymphoma544 (53.8)467 (46.2)
    NHL**247 (45.2)
    B cell††384 (77.0)
    T-cell35 (7.5)
    HL48 (10.4)
  • * Social class was defined as follows: I, managers and professionals; II to III; technicians and allied professionals, other nonmanual; IV to V, skilled manual, semiskilled/unskilled manual, IV, unclassified.

  • Geometric mean value with GSD using log-transformed data.

  • t test mean of ln value.

  • § Tertiles were calculated using log-transformed total IgE values.

  • Positive panel for either grass, animals, molds, or pollens with positive specific IgE defined as ≥0.35 kU/L.

  • All lymphoma category includes B-cell lymphomas: CLL, lymphoplasmatic lymphoma, splenic marginal zone lymphoma, plasma cell myeloma (MM), marginal zone B-cell lymphoma, follicular lymphoma, diffuse large-cell lymphoma, other B-cell lymphoma; T-cell lymphomas: mycosis fungoides/Sézary, other T-cell lymphoma; HL.

  • ** NHL category excludes CLL, MM, and HL.

  • †† B-cell lymphoma category excludes T-cell lymphoma and HL.