Table 2.
Characteristics of NTM culture positive patients stratified by LAM result at grade 1 cut-point
| Characteristic at time of first positive NTM culture | LAM positive ( n = 9) | LAM negative ( n = 14) | p -value |
|---|---|---|---|
| Median age (IQR), y | 19.7 (13.7 – 25.6) | 16.1 (11.9 – 24.0) | 0.41 |
| Female, % | 88.9 | 28.6 | 0.01 |
| Homozygote for Delta 508, % | 78.8 | 85.7 | 0.62 |
| Median FEV1% of pred. (IQR) | 80.0 (70.3 – 84.8) | 70.0 (66.3 – 83.5) | 0.59 |
| Diabetes mellitus, % | 11.1 | 28.6 | 0.32 |
| Structurally defective MBL allele*, % | 55.6 | 7.1 | 0.01 |
| Other chronic infection, % | 77.8 | 50.0 | 0.18 |
| Received NTM treatment, % | 55.6 | 57.1 | 0.94 |
| Number of positive NTM cultures | 11.0 (3.5 – 19.5) | 6.0 (1.8 – 14.5) | 0.68 |
| MABSC, % | 88.9 | 64.3 | 0.19 |
| Fulfilled ATS criteria for NTM, % | 88.9 | 78.6 | 0.52 |
| Median time positive for NTM (IQR), y | 2.5 (1.0 – 4.0) | 3.0 (1.0 – 5.0) | 1.00 |
| Chronic renal disease**, % | 0 | 14.3 | 0.24 |
MABSC = M. abscessus complex, MAC = M. avium complex, NTM = nontuberculous mycobacteria, IQR = Interquartile range, FEV1% = forced expiratory volume in 1 second as percent of predicted for age, height and sex, ATS = American Thoracic Society.
*XA/B (n = 3) or YA/B (n = 3) genotype.
**Defined as renal-clearance below 107 ml/min for adult men and 87 ml/min for adult women or in case of missing renal-clearance measurement, a mean serum creatinine at time of LAM testing over 105 or 90 μmol/L for adult men and women respectively or > 35, 40, 50, 55, 65 or 70 μmol/L for age groups 3-5 y, 6-7 y, 8-9 y, 10-11 y, 12-13 y and 14-15 y respectively.