Sir,
Miliary tuberculosis (TB) is an infection of disseminated hematogenous disease caused by the bacterium Mycobacterium tuberculosis (Mtb). The clinical picture produced by lymphohematogenous dissemination depends on the quantity of organisms released from the primary focus and the adequacy of the host's immune response.[1] We agree with the comments stating that immunocompromised individuals are generally more prone to miliary TB.[2] As the authors mentioned, miliary diseases are found to be significantly more common in human immunodeficiency virus (HIV)-infected children (24.0%) compared to non-HIV-infected children and untested children (2.9%). In non-HIV-infected children, miliary disease was predominantly documented in children below 3 years of age as in our case.[3] Although it was reported that HIV infection incidence has increased in the last decade in Turkey, the total number of pediatric HIV infection cases (in the age group of 0-9 years) between 2007 and 2011 was 27.[4] Our patient's anti-HIV antibody test was negative.[5] Other immunological studies were not found abnormality to be associated with primary immunodeficiency. He recovered with anti-TB treatment and during the 7-year follow-up, any clinical situation that refers to immune deficiency did not occur. In children, Bacillus Calmette-Guérin (BCG) has been demonstrated to prevent disseminated TB, miliary TB, and TB meningitis.[6] Our patient had not received the BCG vaccine.
Interferon-gamma release assays (IGRAs) have several advantages over tuberculin skin test (TCT). IGRAs have greater specificity than TST and can greatly reduce the number of false positive results in children who have received a BCG vaccine or who have been exposed to nontuberculous mycobacteria.[7] However, in children below 5 years of age there is uncertainty about the use of IGRAs. For this age group, there is not enough data and it was reported that indeterminate/invalid results seemed to be higher in infants and toddlers than in older children.[5] Although there is no clear data currently about the use of IGRAs in children below 5 years of age, they are commonly used tests at present. But 7 years ago, it was not easily available in Turkey. Also, 7 years ago there were not sufficient data about the usage of IGRAs. Therefore, we did not use this test at that time.
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Conflicts of interest
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REFERENCES
- 1.Starke JR. Tuberculosis (Mycobacterium tuberculosis) In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, Behrman RE, editors. Nelson Textbook of Pediatrics. United States of America: Elsevier; 2011. pp. 996–1011.e1. [Google Scholar]
- 2.Al-Mendalawi MD. Miliary tuberculosis disease complicated by Pott's abscess in an infant: Seven-year follow-up. Lung India. 2015;32:676–7. doi: 10.4103/0970-2113.168107. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Marais BJ, Gie RP, Schaaf HS, Hesseling AC, Enarson DA, Beyers N. The spectrum of disease in children treated for tuberculosis in a highly endemic area. Int J Tuberc Lung Dis. 2006;10:732–8. [PubMed] [Google Scholar]
- 4.Erbaydar T, Erbaydar NP. Status of HIV/AIDS epidemic in Turkey. Acta Medica. 2012;1:19–24. [Google Scholar]
- 5.Bayhan GI, Tanir G, Gayretli Aydın ZG, Yildiz YT. Miliary tuberculosis disease complicated by Pott's abscess in an infant: Seven year follow-up. Lung India. 2015;32:258–61. doi: 10.4103/0970-2113.156246. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Trunz BB, Fine P, Dye C. Effect of BCG vaccination on childhood tuberculous meningitis and miliary tuberculosis worldwide: A meta-analysis and assessment of cost-effectiveness. Lancet. 2006;367:1173–80. doi: 10.1016/S0140-6736(06)68507-3. [DOI] [PubMed] [Google Scholar]
- 7.Starke JR. Committee on Infectious Diseases. Interferon-γ release assays for diagnosis of tuberculosis infection and disease in children. Pediatrics. 2014;134:e1763–73. doi: 10.1542/peds.2014-2983. [DOI] [PubMed] [Google Scholar]