Tuberculosis in pregnancy and the puerperium

Validation and application of a quantitative LC-MS/MS assay for the analysis of first-line anti-tuberculosis drugs, rifabutin and their metabolites in human breast milk

Breast milk is the preferred method of infant nutrition. Breastfeeding infants born to mothers treated for TB may be at risk of drug toxicity through breast milk exposure, or potentially be vulnerable to select for drug resistance with low level drug exposure. Except for isoniazid, the quantification of first-line TB drugs including rifabutin in breast milk has not been previously described and will provide much-needed insight to TB drug exposure in breastfeeding infants. We developed and validated a novel method to quantify several first-line TB drugs and their major metabolites in breast milk. Accuracy and precision were assessed during three consecutive, independent validation batches over a calibration range of 0.300-30.0 µg/mL for isoniazid and ethambutol, 0.150-15.0 µg/mL for acetyl isoniazid, desacetyl rifampicin, rifampicin, and pyrazinamide, 0.0150-1.50 µg/mL for rifabutin, and 0.00751-0.751 µg/mL for deacetyl rifabutin in breast milk. The method was reproducible for all analytes when using breast milk from six different sources and was not influenced by matrix effects with a mean regression precision (CV(%)) ranging between 1.0 and 2.8. The average recovery of analytes from the matrix was 76.7-99.1%, with a CV(%) between 0.4 and 4.4, while the average process efficiency was between 74.4 and 93.1% with a CV(%) between 1.9 and 8.3. Although only acetyl isoniazid, isoniazid, ethambutol, and pyrazinamide were successfully assayed in breast milk, samples taken from mothers treated for rifampicin-resistant TB and the inclusion of all first-line TB drugs, including rifabutin in the assay development and validation process will allow future quantification of these analytes in breast milk.

Clinical characteristics in 26 children with congenital tuberculosis in Central Southern China: a retrospective study

BACKGROUND

Congenital tuberculosis (CTB) is relatively rare and most patients are described in case reports.

AIM

To investigate the clinical characteristics of CTB in 26 children.

METHODS

A retrospective analysis of 26 children with CTB from January 2013 to December 2021 in Changsha Central Hospital in Central Southern China was undertaken.

RESULTS

The median age at onset was 25 days (17-33) and within 4 weeks of age in approximately 73% of cases. Of 24 mothers (including two mothers of twins), 18 (75.0%) were asymptomatic during pregnancy, and four were diagnosed with tuberculosis prenatally. The numbers of tuberculous meningitis, tuberculous encephalitis and liver TB were 17 (65.4%), five (19.2%) and four (15.4%), respectively. The main symptoms were fever (n = 18, 69.2%) and cough (n = 16, 61.5%). Positive rates of T-SPOT.TB, acid-fast bacilli smear, culture of Mycobacterium tuberculosis and GeneXpert MTB/RIF test were, respectively, 84.2% (16/19), 42.3% (11/26), 43.5% (10/23) and 83.3% (5/6). Radiograph or computed tomography demonstrated typical pulmonary tuberculous lesions in all cases and the head magnetic resonance imaging (MRI) showed marked meningeal enhancement or parenchymal lesions in seven cases (26.9%). One case had drug-resistant TB. During follow-up, nine cases had varying degrees of liver injury, and one had delayed growth and development. Eight died and 18 recovered satisfactorily.

CONCLUSION

Maternal TB status during pregnancy, the epidemiological history, T-SPOT.TB and other TB-related aetiological tests and imaging are important for the early diagnosis and treatment of CTB, and are associated with a favourable outcome.

ABBREVIATIONS

AFB: acid-fast bacilli; Amk: amikacin; Cs: cycloserine; CT: computed tomography; E: ethambutol; GeneXpert MTB/RIF: GeneXpert Mycobacterium tuberculosis and rifampicin resistance; H: isoniazid; IVF-ET: in-vitro fertilization-embryo transfer; Lzd: linezolid; Mfx: moxifloxacin; MTB: Mycobacterium tuberculosis; mNGS: next generation sequencing; MTB-DNA: Mycobacterium tuberculosis-deoxyribonucleic acid; Pto: protionamide; R: rifampicin; TB: tuberculosis; T-SPOT.TB: spot test of mycobacterium TB infection T-lymphocytes; Z: pyrazinamide.