International Journal of Infectious Diseases 57 (2017) 116–122
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Hepatitis C virus and human T-cell lymphotropic virus type 1 co-infection: impact on liver disease, virological markers, and neurological outcomes Otávio M. Espíndolaa,1, Alexandre G. Vizzonia,1, Elisabeth Lampeb , Maria José Andrada-Serpaa , Abelardo Q.C. Araújoa , Ana Claudia C. Leitea,* a Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute for Infectious Diseases (INI) — Oswaldo Cruz Foundation (FIOCRUZ), Avenida Brasil, 4365, Manguinhos, Rio de Janeiro,RJ 21040-900, Brazil b Laboratory of Viral Hepatitis, Oswaldo Cruz Institute (IOC) — FIOCRUZ, Rio de Janeiro, Brazil
A R T I C L E I N F O
S U M M A R Y
Article history: Received 14 September 2016 Received in revised form 26 January 2017 Accepted 27 January 2017 Corresponding Editor: Eskild Petersen, Aarhus, Denmark
Objectives: Human T-cell lymphotropic virus type 1 (HTLV-1) infection is associated with neurological abnormalities, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and peripheral neuropathy (PN). Hepatitis C virus (HCV) infection is the leading cause of chronic liver disease worldwide, and causes PN in approximately 9% of patients. Because the interplay between these potentially neuropathogenic viruses in the same individual is still poorly understood, the clinical and laboratory outcomes of co-infected patients were evaluated and compared with those of controls. Methods: The prevalence rates of neurological and laboratory abnormalities were evaluated in HCV/ HTLV-1 co-infected patients (n = 50), and in subjects with single HCV (n = 46) or HTLV-1 (n = 150) infection. Results: A higher frequency of isolated PN was present in HCV-infected patients; this was not associated with cryoglobulinemia. No difference was found in the frequency of PN or HAM/TSP when co-infected subjects were compared to singly infected subjects. Hepatic involvement was present in HCV-infected subjects, as shown by increased levels of serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and bilirubin, in addition to thrombocytopenia. On the other hand, HCV/ HTLV-1 co-infected individuals presented a better prognosis for hepatic involvement when compared with singly HCV-infected subjects. Conclusions: These data suggest that HCV/HTLV-1 co-infection does not mutualistically alter the outcome with regard to neurological manifestations. Nonetheless, changes in the immunological environment induced by HTLV-1 infection could lead to a reduction in hepatic damage, even without significant HCV clearance. © 2017 Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: HCV HTLV-1 Co-infection Hepatic involvement Peripheral neuropathy
Introduction Human T-cell lymphotropic virus type 1 (HTLV-1) infects 5–10 million people worldwide and is endemic in Japan, the Caribbean, Sub-Saharan Africa, the Middle East, and South America, particularly in Brazil.1 HTLV-1 causes a persistent infection of CD4+ and CD8+ T-cells that leads to diverse changes in the immune response.2 It can be associated with the development of adult Tcell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP).3 In addition to its
* Corresponding author. Tel.: +55 21 3865 9543. E-mail addresses:
[email protected], ana.leite@ini.fiocruz.br (A.C.C. Leite). Otávio M. Espíndola and Alexandre G. Vizzoni contributed equally.
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pathogenic role in these diseases, HTLV-1 has also been associated with other immune-mediated conditions, such as uveitis, polymyositis, chronic inflammatory arthropathy, and increased susceptibility to some opportunistic infections.4 Most HTLV-1-infected individuals remain asymptomatic carriers and only 0.5–5% of them develop disease.5 Several studies have suggested that HTLV-1 is associated with a wider spectrum of neurological manifestations that do not fulfill the diagnostic criteria for HAM/TSP.3 These symptoms and conditions may later progress to classical HAM/TSP or remain as isolated neurological syndromes, such as sensory neuropathy,6,7 bladder dysfunction,8 erectile dysfunction,9 amyotrophic lateral sclerosis-like syndrome,10 mild cognitive deficits,11 and more rarely, motor neuropathies.12 Events or mechanisms that trigger the
http://dx.doi.org/10.1016/j.ijid.2017.01.037 1201-9712/© 2017 Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
O.M. Espíndola et al. / International Journal of Infectious Diseases 57 (2017) 116–122
neurological involvement in HTLV-1 are still unknown. However, a high HTLV-1 proviral load (PVL) in peripheral blood has been associated with the development of neurological abnormalities.13 Hepatitis C virus (HCV) infection is the leading cause of chronic liver disease worldwide, and it is estimated that about 185 million individuals are or have been infected throughout the world.14 The average prevalence of HCV seropositivity in Brazil is around 1.23% among blood donors, and in Rio de Janeiro the estimated prevalence is 2.6%.15 The majority of HCV-infected individuals establish a chronic infection, and 74–86% present detectable viremia in peripheral blood. In 25–30% of cases, chronic infection can progress to severe complications, such as chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC).16 It is also estimated that 40–74% of HCV-infected individuals can develop at least one extrahepatic manifestation, such as mixed cryoglobulinemia, membranoproliferative glomerulonephritis, sicca syndrome, and porphyria cutanea tarda, among others.17 Peripheral neuropathy (PN) can be found in 9% of patients with chronic HCV infection, regardless of the presence of cryoglobulinemia.18 Involvement of the central nervous system (CNS),19,20 the peripheral nervous system (PNS),21 and less frequently the autonomic nervous system, has also been documented, either as a direct manifestation of the infection or as a paraneoplastic presentation in cases of HCC.22 HCV/HTLV-1 co-infection may be common, particularly in countries where these viruses are endemic, since they share similar modes of transmission. This is especially true in certain population groups, such as in persons who have unprotected sex habits, intravenous drug users (IDU), and individuals with a history of blood transfusion.23,24 The cellular immune response appears to play an important role not only in viral clearance in both infections,25,26 but also in the immunopathogenesis of the hepatic lesions in HCV infection16 and in the neurological involvement in HTLV-1 infection.3 The interplay between these two neuropathogenic viruses in the same individual is still poorly understood. It has been shown by some that, when compared to HCV-monoinfected patients, HCV/HTLV1 co-infection has a synergistic effect on incident liver disease, as well as on deaths from HCC.23 However, other groups have postulated that HTLV-1 infection can attenuate hepatic damage, as shown by lower serum levels of aminotransferases and lower degrees of liver fibrosis.27,28 Similar results were observed in a study with triple HIV, HCV, and HTLV-1 co-infection, in which HTLV-1-infected patients presented better outcomes for HCVassociated liver fibrosis.26 The present study was performed to provide new insights into the interactions between HCV and HTLV-1 infections through an evaluation of abnormalities in hepatic parameters and the neurological outcomes of HCV/HTLV-1 co-infection. Materials and methods Patients and data collection This cross-sectional study was conducted from 2008 to 2010 at the Evandro Chagas National Institute for Infectious Diseases (INI/ FIOCRUZ), Rio de Janeiro, Brazil. The study was approved by the local ethics committee (INI 2009/0028.0.009.000.08), and written informed consent was obtained from all patients involved in the research protocol. HTLV-1-infected individuals (n = 150) were selected randomly from a cohort of 650 subjects regularly attending the outpatient clinic at INI/FIOCRUZ. HCV/HTLV-1 coinfected patients (n = 50) from this same cohort were enrolled in the study when inclusion criteria were fulfilled. HCV-infected individuals (n = 46) were selected randomly from outpatient cohorts followed at the Gaffrée and Guinle University Hospital
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(HUGG-UNIRIO), Rio de Janeiro, and at the Oswaldo Cruz Institute (IOC/FIOCRUZ). Individuals concurrently infected with HIV, HTLV2, syphilis, or hepatitis B virus (HBV), or presenting conditions that could by themselves cause PN (such as vitamin B12 deficiency, chronic use of potentially neurotoxic drugs, diabetes, leprosy, and renal or genetic diseases) were excluded from this study. Neurological evaluation Patients were classified as neurological asymptomatic or as HAM/TSP according to the modified World Health Organization criteria, as described previously.29 HTLV-1-infected patients with urinary urgency/incontinency/retention and with an abnormal urodynamic evaluation, but without PNS or CNS involvement, were classified as presenting an isolated neurogenic bladder.8 Due to the close relationship between HCV infection and PN, as reported in the literature,21 a full evaluation of the PNS was prioritized. A diagnosis of PN was made when one or more of the following clinical criteria were fulfilled: numbness, burning sensation, pain in a stocking or glove distribution, distal weakness, and diminished or absent deep reflexes with or without distal muscular atrophy. With regard to electromyography (EMG) and nerve conduction studies (NCS), the following diagnoses were considered according to classical criteria30 : polyneuropathy or multiple mononeuropathy. The presence of specific histological abnormalities in a sural nerve biopsy was also considered a hallmark of pathological involvement of the peripheral nerve. Isolated PN was identified in patients presenting signs and/or symptoms of PN and an abnormal NCS/EMG and/or abnormalities in the sural nerve biopsy, and also when clinical criteria of PN were present without confirmation by NCS/EMG and/or histological evaluation of the peripheral nerve.12 Clinical and laboratory data Sociodemographic data such as sex, age, IDU status, alcohol consumption, self-reported history of blood transfusion, number of sexual partners, and practice of unprotected sex were assessed. Peripheral blood was collected in ethylenediaminetetraacetic acid (EDTA) and processed on the same day for DNA extraction, for subsequent HTLV-1 PVL quantification, and for determining the complete blood count and CD4+ and CD8+ T-cell counts by flow cytometry (FACSCalibur, Becton Dickinson). Plasma was obtained from peripheral blood in EDTA by centrifugation at 1500 g for 10 min and used for the assessment of cryoglobulins, as described previously.31 Serum samples were processed within 4 h for the quantification of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), and total bilirubin levels, or aliquoted and stored at 80 C for later analysis. Liver fibrosis and cirrhosis were predicted using the AST to platelet count ratio index (APRI).32 The diagnosis of HTLV-1 was based on the detection of specific anti-HTLV-1 antibodies in serum by enzyme immunoassay (EIA) (Anti-HTLV-I/II Sym Solution; Symbiosys, São Paulo, Brazil) and confirmed by Western blot (HTLV Blot 2.4; Genelabs Technologies, Singapore). The diagnosis of HCV infection was performed using a third-generation EIA (ETI-AB-HCVK-4; Diasorin, Vercelli, Italy), in accordance with the manufacturer’s recommendations. The diagnosis was confirmed by HCV RNA genomic amplification (Amplicor HCV Test, v2.0; Roche Diagnostics, France). HCV genotyping was performed using the Versant HCV Genotype Assay — LiPA (Bayer Corporation, Tarrytown, NY, USA), which can discriminate HCV genotypes 1 to 6. The quantification of HCV viral load was performed using the Cobas Amplicor HCV Monitor Test, v2.0 system (Roche Diagnostics, France), as per the manufacturer’s instructions. HTLV-1 PVL was determined by quantitative PCR, as
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described previously,13 and recorded as the frequency of HTLV-1infected cells in peripheral blood leukocytes (PBL).
The statistical analysis was performed using IBM SPSS v. 20 software (IBM Corp., Armonk, NY, USA). Comparisons of categorical variables among groups were performed by Pearson’s Chi-square test, or by Fisher’s exact test when the cell size was 60 Route of transmission IDU Blood transfusion Sexuale Breast feeding Not reported Alcohol consumption Yes No Not reported
HCV/HTLV-1 n (%)
HCV n (%)
HTLV-1 n (%)
32 (64.0)* 18 (36.0)
20 (43.5) 26 (56.5)
59 (39.3) 91 (60.7)*
– 6 (12.0) 36 (72.0) 8 (16.0)
– 7 (15.2) 25 (54.3) 14 (30.4)
1 (0.7) 26 (17.3) 28 (45.3) 55 (36.7)
11 (28.2)* 16 (41.0) 12 (30.8) 0 11
0 29 (80.6)* 7 (19.4) 0 10
1 (0.9) 18 (15.7) 71 (61.7)* 25 (21.7) 35
14 (37.8) 23 (62.2) 13
22 (47.8)* 24 (52.2) –
34 (27.0) 92 (73.0) 24
p-Value 0.010a
>0.050b
1.50 (fibrosis) >2.00 (cirrhosis) Medianb (IQR) Cryoglobulinemiad Positive, n (%) Negative, n (%)
HCV/HTLV-1
HCV
HTLV-1
Chi-square testa
p-Valuea
22 (47.8) 37.50 (23.75–52.09)
27 (67.5) 58.50 (31.00–90.75)
15 (10.9) 24.00 (18.00–32.00)
58.75 –
