International Journal of Infectious Diseases (2009) 13, e77—e78
http://intl.elsevierhealth.com/journals/ijid
LETTER TO THE EDITOR Fatal severe dengue and cell death in sickle cell disease during the 2001—2002 Havana dengue epidemic Dengue is considered a major international public health concern. It is caused by any of the four dengue virus serotypes (DEN-1 to 4), a RNA virus of the family Flaviviridae. Dengue can result in a broad spectrum of diseases, ranging from a self-limited sickness, dengue fever, to a severe and potentially fatal disease, dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Unfortunately, case fatality rates can exceed 20% if the correct therapy is not selected rapidly.1,2 A growing body of evidence has demonstrated that the pathogenesis of DHF/DSS is a complex and multifactorial process involving viral, immunological and host factors.1—3 Secondary dengue infections have been shown to be the most important single risk factor for DHF/DSS,1,2 even 20 years or more after contracting the disease.4,5 Individuals with certain chronic conditions, such as sickle cell disease (SCD), are probably at increased risk.1,3,4 Very recently, apoptotic cell death in neuronal cells, leukocytes and endothelial cells (ECs) of blood microvessels was demonstrated for the first time in fatal DHF/DSS caused by DEN-2 in Cuba. Remarkably, apoptotic ECs were probably associated with vascular leakage.6 In this study, we report two (cases A and B) out of three adult fatal dengue cases from the DEN-3 Havana epidemic of 2001— 2002,4 after informed consent was obtained from the deceased patients’ next-of-kin. Notably, both patients suffered from SCD4 and presented grade IV DHF/DSS (following the World Health Organization case definition).7 A secondary dengue infection was confirmed serologically in both cases. In case A, DEN-3 was isolated in mosquito cell culture C6/36-HT from the patient’s serum, fresh liver and spleen tissue specimens; viral RNA was also detected from fresh liver and spleen tissue. DEN-3 multiplication in the same mosquito cell line and viral RNA was demonstrated in case B from a serum sample. A cell death assay using the terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) method (In Situ Cell Death Detection Kit, Roche Applied Science) was carried out on formalin-fixed, paraffinembedded sections of intestinal and myocardial tissue from
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This research was partly presented at the 6 International Cell Death Symposium, Rio de Janeiro, Brazil, 2006 (session number: B 08) and the 13th International Congress of Immunology, Rio de Janeiro, Brazil, 2007 (session number: P4.19).
cases A and B, and also brain tissue from case A. An immunohistochemical assay for dengue antigen localization6 was also performed. In both subjects, no DEN antigens were detected in the tissues, but apoptotic neuronal cells in case A. Despite vascular leakage (ascites) in the same patient, apoptosis in ECs of the intestinal microvasculature was not observed. Previous work demonstrated apoptotic hepatocytes in Vietnamese children who died of DHF/DSS caused by DEN-3.8 In this work, we demonstrate cell death in the neurons of a fatal severe DEN-3 case. To our knowledge, apoptosis in the neurons of a DEN-3 fatality has not been previously reported. In spite of an in vitro study suggesting that sickle cell hemoglobin might be neurotoxic and thus induce neuronal apoptosis,9 we can not exclude that, similar to our previous report concerning nonSCD patients,6 a metabolic/vascular-mediated mechanism might be involved in the neuronal apoptotic pathway. Interestingly, we could not show DEN antigen in the brain tissues of fatal cases in our previous and current studies. Whether immunopathological features of SCD participate in the increased risk of severe DHF/DSS still needs further investigation. Some studies suggest that activated monocytes in SCD might activate ECs through different cytokines that contribute to frequent SCD microvascular occlusions,10 altering EC apoptosis, immune responses and hemopoiesis.11 More detailed investigations are needed to elucidate the association of apoptosis with severe dengue physiopathology and non-infectious co-morbidities. Conflict of interest: No conflict of interest to declare. No competing interests declared Funding: None Ethical Approval: N/A
Acknowledgements We thank Prof. Jose L. Pelegrino of the Virology Department at our Tropical Medicine Institute for his pioneering work on in vivo apoptosis in dengue disease.
References 1. Guzman MG, Kouri G. Dengue: an update. Lancet Infect Dis 2002;2:33—42. 2. Halstead SB. Dengue. Lancet 2007;370:1644—52. 3. Bravo JR, Guzman MG, Kouri GP. Why dengue haemorrhagic fever in Cuba? 1. Individual risk factors for dengue haemorrhagic
1201-9712/$36.00 # 2008 Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. doi:10.1016/j.ijid.2008.06.028
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Letter to the Editor fever/dengue shock syndrome (DHF/DSS) Trans R Soc Trop Med Hyg 1987;81:816—20. Gonzalez D, Castro OE, Kouri G, Perez J, Martinez E, Vazquez S, et al. Classical dengue hemorrhagic fever resulting from two dengue infections spaced 20 years or more apart: Havana, Dengue 3 epidemic, 2001-2002. Int J Infect Dis 2005;9:280—5. Guzman MG, Alvarez M, Rodriguez-Roche R, Bernardo L, Montes T, Vazquez S, et al. Neutralizing antibodies after infection with dengue 1 virus. Emerg Infec Dis 2007;13:282—6. Limonta D, Capo V, Torres G, Pe ´rez AB, Guzma ´n AG. Apoptosis in tissues from fatal dengue shock syndrome. J Clin Virol 2007;40:50—4. PAHO. Dengue and dengue hemorrhagic fever in the Americas: guidelines for prevention and control. Washington, DC:PAHO. 1994. Huerre MR, Lan NT, Marianneau P, Hue NB, Khun H, Hung NT, et al. Liver histopathology and biological correlates in five cases of fatal dengue fever in Vietnamese children. Virchows Arch 2001;438:107—15. Vanderveldt GM, Regan RF. The neurotoxic effect of sickle cell hemoglobin. Free Radic Res 2004;38:431—7. Belcher JD, Marker PH, Weber JP, Hebbel RP, Vercellotti JM. Activated monocytes in sickle cell disease: potential role in the activation of vascular endothelium and vaso-occlusion. Blood 2000;96:2451—9. Makis AC, Hatzimichael EC, Bourantas KL. The role of cytokines in sickle cell disease. Ann Hematol 2000;79:407—13.
Daniel Limonta Virology Department, Pedro Kourı´ Tropical Medicine Institute, PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Havana, Cuba
Daniel Gonza ´lez Department of Medicine, Pedro Kourı´ Tropical Medicine Institute, PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Havana, Cuba Virginia Capo ´ Griselda Torres Pathology Department, Pedro Kourı´ Tropical Medicine Institute, PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Havana, Cuba Ana B. Pe ´rez Delfina Rosario Rosmari Roche-Rodriguez Mayling Alvarez Marı´a G. Guzma ´n* Virology Department, Pedro Kourı´ Tropical Medicine Institute, PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, Havana, Cuba *Corresponding author. Tel.: +53 7 2020450/2020633; fax: +53 7 2046051 E-mail address:
[email protected] Corresponding Editor: William Cameron, Ottawa, Canada 17 February 2008
