Table 2 Factors affecting Ig levels (log₁₀ median fluorescent intensity) 5–9 months after COVID-19 by multivariable stepwise regression models

IgA

Age

0.9 (0.15; 1.66)

1.9 (0.77; 3.04)

0.48 (− 0.46; 1.43)

0.98 (− 0.23; 2.22)

1.02 (− 0.54; 2.61)

Shivers

7.38 (− 8.68; 26.27)

17.13 (− 7.94; 49.02)

18 (− 3.79; 44.74)

18.04 (− 9.27; 53.59)

9.08 (− 22.22; 52.98)

Symptoms duration

0.21 (− 0.09; 0.52)

0.46 (0.01; 0.92)

0.48 (0.1; 0.87)

0.57 (0.07; 1.06)

0.35 (− 0.29; 0.99)

Sputum

− 0.53 (− 27.1; 35.73)

21.77 (− 23.28; 93.26)

26.52 (− 14.49; 87.19)

4.24 (− 37.08; 72.7)

− 12.9 (− 54.47; 66.64)

Fever

− 5.07 (− 21; 14.07)

9.16 (− 16.92; 43.43)

13.39 (− 10.05; 42.93)

28 (− 5.02; 72.5)

26.53 (− 13.77; 85.65)

Anosmia/hypogeusia

7.96 (− 7.85; 26.48)

− 1.43 (− 22.1; 24.72)

3.22 (− 15.45; 26.03)

24.88 (− 3.44; 61.51)

49.2 (7.2; 107.64)

Hospitalization

14.35 (− 23.18; 70.2)

− 8.98 (− 49.6; 64.39)

79.25 (8.58; 195.91)

47.25 (− 22.82; 180.94)

85.13 (− 19.29; 324.64)

Hypertension

18.89 (− 11.13; 59.07)

56.55 (1.57; 141.29)

8.63 (− 24.73; 56.77)

− 12.94 (− 45.74; 39.69)

12.92 (− 38.5; 107.32)

Dizziness

− 4.2 (− 21.91; 17.53)

− 1.46 (− 27.28; 33.52)

18.82 (− 8.17; 53.73)

20.71 (− 13.39; 68.25)

35.75 (− 11.4; 107.98)

Oxygen

17.09 (− 27.3; 88.57)

35.15 (− 33.44; 174.42)

− 18.38 (− 55.23; 48.81)

− 13.7 (− 60.2; 87.14)

− 34.56 (− 75.8; 76.93)

Cough

9.41 (− 7.11; 28.87)

4.24 (− 18.27; 32.95)

6.83 (− 13.09; 31.31)

14.26 (− 12.42; 49.07)

3.92 (− 26.15; 46.25)

IgG

Age

2.71 (1.37; 4.08)

2.23 (1.2; 3.27)

2.3 (0.66; 3.97)

1.31 (− 0.2; 2.84)

0.69 (− 0.4; 1.79)

Shivers

27.7 (− 5.25; 72.12)

12.11 (− 10.82; 40.94)

27.37 (− 11.63; 83.59)

17.65 (− 16.21; 65.21)

6.24 (− 16.88; 35.79)

Dyspnea

8.58 (− 20.4; 48.09)

1.35 (− 20.11; 28.57)

− 0.57 (− 32.02; 45.42)

3.96 (− 26.96; 47.97)

− 4.24 (− 25.81; 23.59)

Fever

107.38 (49.19; 188.25)

89.46 (47.19; 143.88)

192.5 (95.41; 337.82)

152.84 (73.85; 267.7)

82.01 (38.84; 138.59)

Anosmia/hypogeusia

50.43 (13.84; 98.8)

58.13 (27.7; 95.8)

90.52 (35.41; 168.06)

104.14 (48.67; 180.3)

73.92 (38.3; 118.71)

Hospitalization

36.15 (− 31.97; 172.47)

7.73 (− 36.71; 83.38)

52.13 (− 34.96; 255.88)

38.26 (− 37.19; 204.38)

29.59 (− 26.74; 129.24)

Dizziness

4.2 (− 27.37; 49.48)

12.64 (− 14.58; 48.54)

17.46 (− 24.5; 82.75)

6.62 (− 29.27; 60.73)

3.68 (− 22.94; 39.49)

Myalgia/arthralgia

− 0.88 (− 26.47; 33.62)

− 5.9 (− 25.16; 18.31)

− 16.5 (− 42.08; 20.39)

− 9.84 (− 35.81; 26.64)

− 8.22 (− 28.2; 17.32)

Oxygen

13.09 (− 51.02; 161.11)

14.62 (− 39.65; 117.71)

38.62 (− 50.26; 286.33)

27.63 (− 50.73; 230.58)

6.18 (− 46.63; 111.25)

Cough

23.2 (− 7.49; 64.07)

21 (− 2.86; 50.73)

29.93 (− 8.52; 84.56)

23.34 (− 10.96; 70.86)

21.7 (− 3.84; 54.03)

Ex-smoker

0.69 (− 27.97; 40.75)

− 4.64 (− 26.23; 23.28)

4.65 (− 30.57; 57.72)

5.92 (− 27.63; 55.04)

2.3 (− 22.32; 34.72)

Smoking

− 43.78*(− 66.34; − 6.09)

− 36.12 (− 56.9; − 5.34)

− 51.11 (− 73.92; − 8.34)

− 44.12 (− 68.82; 0.16)

− 32.05 (− 55.43; 3.61)

IgM

Shivers

− 6.18 (− 18.05; 7.4)

0.41 (− 15.79; 19.72)

14.29 (− 9.05; 43.62)

15.08 (− 5.92; 40.77)

7.81 (− 12.62; 33.01)

Pain chest

19.63 (0.22; 42.79)

6.45 (− 15.45; 34.01)

2.84 (− 23.74; 38.68)

8.62 (− 16.56; 41.39)

20.01 (− 8.85; 57.99)

Sputum

3.67 (− 20.83; 35.77)

7.94 (− 24.01; 53.31)

45.59 (− 7.68; 129.61)

24.46 (− 16.72; 86.02)

0.26 (− 34.07; 52.45)

Anosmia/hypogeusia

− 1.56 (− 14.2; 12.94)

− 2.61 (− 18.55; 16.45)

3.32 (− 18.08; 30.31)

4.06 (− 15.21; 27.7)

22.74 (− 0.86; 51.96)

Hospitalization

4.63 (− 25.82; 47.59)

8.15 (− 30.87; 69.19)

38.26 (− 22.67; 147.19)

31.32 (− 21.34; 119.23)

33.55 (− 21.74; 127.92)

Oxygen

− 6.06 (− 37.76; 41.79)

24.27 (− 27.26; 112.31)

40.07 (− 30.12; 180.75)

22.2 (− 33.82; 125.64)

− 19.77 (− 57.68; 52.09)

Cough

7.06 (− 7.33; 23.46)

3.06 (− 13.72; 25.31)

16.5 (− 8.05; 49.27)

14.89 (− 6.65; 43.13)

20.07 (− 3.52; 50.67)

Obesity

− 15.41 (− 31.54; 4.53)

− 25.48 (− 43.42; − 1.86)

− 19.05 (− 43.38; 15.73)

− 19.68 (− 41.4; 10.09)

− 13.48 (− 37.72; 20.21)