To the Editor
We thank the authors of this letter [Citation1] for the comments regarding our review [Citation2], and also for sharing the data from Greece.
We agree with your statement that adenosine deaminase (ADA) is fundamental in the diagnosis of Pleural tuberculosis (PT), due to its low cost and ease of management. In the region we live its use is well established between internists and pulmonologists. Our main concern is to take it to daily practice in the other centers of our continental country.
Brazil registered 72,000 new cases of tuberculosis (TB) in 2018 and 73,000 in the previous year according to the Brazilian Ministry of Health [Citation3]. We do not have the exact prevalence of PT. According to data published by Seiscento et al. [Citation4], approximately 8% of new cases are due to PT, which would give an estimate incidence of 5040 cases. In a cross-sectional study involving all TB cases reported to the Brazilian Notifiable Diseases Surveillance System (SINAN) between 2007 and 2011, it was estimated that PT represented 6.9% of TB cases [Citation5]. Unfortunately, we have no more epidemiological studies confirming this data, and also how the diagnosis of PT was done.
Currently, in the private health care system, most laboratories provide ADA analysis. However, in the public health system, ADA dosage is available mainly in the largest metropolitan centers of the Brazilian geographic regions.
Focusing on physicians who are in places with less access to clinical laboratories and need help in diagnosing pleural effusion, we conducted studies regarding how time and storage conditions would affect the quality of pleural fluid (PF) analysis, including cytology [Citation6–Citation8]. We showed that temperature and storage time are potential pre-analytical errors in some biochemical analysis, especially in glucose and LDH stability. In the case of PF ADA, samples centrifuged within 1h after collection, can be submitted to ADA determination for up to 28 days if stored at 4ºC or −20ºC, with no significant increases or decreases in the enzyme activity. For cytological examination, we demonstrated that PF samples collected in ethylenediaminetetraacetic acid (EDTA) coated tubes and kept refrigerated until analysis can be processed up to 48 h of collection, without evidence of significant morphological changes.
We also believe that a close cooperation among general practitioners, who work in primary care centers, with pulmonologists and clinical laboratories is the key partnership to optimize diagnosis and assist in the eradication of TB as proposed by WHO.
Declaration of interest
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
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References
- Zouridis S, Kotsiou OS, Gerogianni I, et al. Letter to the Editor: “Necessity of co-operation between pulmonologists and internists in tuberculous pleurisy diagnosis. Expert Rev Respir Med. 2019;13(11). doi:10.1080/17476348.2019.1667234.
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