Optimizing the Detection of Recent Tuberculosis Infection in Children in a High Tuberculosis–HIV Burden Setting
Anna M. Mandalakas, H. Lester Kirchner, Gerhard Walzl, Robert P. Gie, H. Simon Schaaf, Mark F. Cotton, Harleen M. S. Grewal, and Anneke C. Hesseling
American Journal of Respiratory and Critical Care Medicine, Vol. 191, No. 7 (2015), pp. 820-830.
南アフリカからの報告．
＜背景＞
若年，低栄養，ＨＩＶ感染の子供は結核感染のリスクが高い．
南アフリカでは結核治療は検査不足，データ不足のため遅れている．
＜目的＞
小児の結核感染を改善する検査を探索する
＜方法＞
結核，ＨＩＶとも高蔓延地域において，(n = 1,343; 6 mo to <15 yr)に
ツベルクリン， IFN-γ release assaysを施行した前向き研究．
＜結果＞
３カ月以内の接触を持続的に追跡すると８％の小児に結核が見つかった．
接触歴のない小児に対するツベルクリン反応とクオンティフェロンＧＯＬＤの陽性率は
Ｔ－ＳＰＯＴよりも高かった．
約８％の子供でIFN-γ release assay 陽性，ツベルクリン陰性の不一致があった．
すべての検査は結核の接触と関連していたが，
IFN-γ release assays のほうがツベルクリンよりもより関連していた(P = 0.0011).
IFN-γ release assaysのあいまいな結果と年齢は関連なかった．
クオンティフェロンＴＢゴールドあいまいな結果はＨＩＶ陽性（4.7％）のほうがＨＩＶ陰性（1.9％）よりも多かった．
一方， T-SPOT.TB のあいまいな結果はまれ（0.2％）であり，ＨＩＶと関係しなかった．
転換（陰性から陽性），復帰（陽性から陰性）はＨＩＶと関連しなかった．
ＨＩＶ陽性の小児では，検査と接触との関連は栄養が悪くなると弱くなった．
＜感想＞
資源が許すようであれば，小児のＨＩＶ患者に対する結核の検査は
IFN-γ release の方がツベルクリンよりもよいようです．
Rationale: Children who are young, malnourished, and infected with HIV have significant risk of tuberculosis (TB) morbidity and mortality following TB infection. Treatment of TB infection is hindered by poor detection and limited pediatric data.
Objectives: Identify improved testing to detect pediatric TB infection.
Methods: This was a prospective community-based study assessing use of the tuberculin skin test and IFN-γ release assays among children (n = 1,343; 6 mo to <15 yr) in TB-HIV high-burden settings; associations with child characteristics were measured.
Measurements and Main Results: Contact tracing detects TB in 8% of child contacts within 3 months of exposure. Among children with no documented contact, tuberculin skin test and QuantiFERON-TB Gold In-Tube positivity was greater than T-SPOT.TB. Nearly 8% of children had IFN-γ release assay positive and skin test negative discordance. In a model accounting for confounders, all tests correlate with TB contact, but IFN-γ release assays correlate better than the tuberculin skin test (P = 0.0011). Indeterminate IFN-γ release assay results were not associated with age. Indeterminate QuantiFERON-TB Gold In-Tube results were more frequent in children infected with HIV (4.7%) than uninfected with HIV (1.9%), whereas T-SPOT.TB indeterminates were rare (0.2%) and not affected by HIV status. Conversion and reversion were not associated with HIV status. Among children infected with HIV, tests correlated less with contact as malnutrition worsened.
Conclusions: Where resources allow, use of IFN-γ release assays should be considered in children who are young, recently exposed, and infected with HIV because they may offer advantages compared with the tuberculin skin test for identifying TB infection, and improve targeted, cost-effective delivery of preventive therapy. Affordable tests of infection could dramatically impact global TB control.
Read More: http://www.atsjournals.org/doi/abs/10.1164/rccm.201406-1165OC