TABLE 4.
Correlation between protein-specific IgG, IgM, and IgA antibody levels and RTIs in children
| Time of measurement and antibody | MFI level in children with indicated no. of RTIs in 3rd year of lifea |
||
|---|---|---|---|
| Never (n = 29) | ≥3 times (n = 5) | P value | |
| 6 mo | |||
| IgG | |||
| BVH-3 | 779 (42-1,931) | 133 (99-168) | 0.050b |
| SP1003 | 2,138 (344-15,291) | 826 (448-1,205) | 0.050b |
| NanA | 173 (38-654) | 40 (37-43) | 0.038b |
| IgA | |||
| Eno | 10 (0-217) | 1 (0-2) | 0.063 |
| IgA1 protease | 2,859 (846-6,454) | 1,190 (1,061-1,319) | 0.064 |
| NanA | 21 (0-146) | 0 (0-0) | 0.022b |
| SP0376 | 18 (1-329) | 3 (2-3) | 0.049b |
| SP1003 | 11 (0-1,102) | 0 (0-0) | 0.061 |
| 14 mo | |||
| IgG | |||
| NanA | 701 (46-3,019) | 252 (9-865) | 0.045b |
| PpmA | 985 (0-12,962) | 0 (0-296) | 0.015b |
| PsaA | 13,531 (833-16,944) | 4,091 (769-11,533) | 0.021b |
| SlrA | 58 (0-2,550) | 9 (3-20) | 0.032b |
| SP0189 | 127 (31-1,512) | 58 (22-96) | 0.030b |
| SP1003 | 9,823 (53-18,717) | 522 (27-7,307) | 0.021b |
| IgM | |||
| IgA1 protease | 202 (0-2,690) | 0 (0-97) | 0.026b |
| BVH-3 | 67 (0-1,187) | 0 (0-9) | 0.041b |
| IgA | |||
| PpmA | 14 (0-1,454) | 0 (0-62) | 0.074 |
| SP1003 | 870 (1-7,807) | 298 (0-571) | 0.021b |
| 24 mo | |||
| IgG | |||
| PpmA | 2,047 (0-8,113) | 518 (0-1,101) | 0.065 |
| SlrA | 335 (15-3,975) | 53 (34-74) | 0.049b |
| SP1003 | 14,161 (2,018-18,743) | 8,007 (81-11,630) | 0.075 |
| IgM | |||
| PspA | 40 (0-1,817) | 154 (98-234) | 0.066c |
| IgA | |||
| SlrA | 20 (0-979) | 0 (72-712) | 0.059 |
a
Values are median MFI levels (5 to 95% range), reflecting antigen-specific IgG, IgM, or IgA levels. All correlations with a P value of <0.08 are shown.
b
P value < 0.05.
c
Increased levels occurred in children with frequent RTIs.