Significance of indeterminate reactivity to human T-Cell lymphotropic virus in Western blot analysis of individuals at risk

Medrano, Francisco J.; Soriano, Vincent; Calderón, E.; Rey, C.; Gutiérrez, M.; Bravo, R.; Leal, Manuel; González-Lahoz, Juan; Lissén, E

doi:10.1007/bf01709592

Cited by 19 publications

(10 citation statements)

References 16 publications

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“…27 28 We found three HTLV-II infected women who had an indeterminate pattern on western blot. All three were Spanish natives, IDUs, and coinfected with HIV-1.…”

Section: Discussionmentioning

confidence: 86%

Prevalence of HTLV infection in pregnant women in Spain

Machuca

Tuset²,

Soriano³

et al. 2000

Sexually Transmitted Infections

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Objective: To estimate the prevalence of HTLV infection among pregnant women in Spain. Methods: A commercial ELISA incorporating HTLV-I and HTLV-II antigens was used for HTLV antibody screening. Repeatedly reactive samples were further examined by western blot. Moreover, confirmation with PCR was performed when cells were available. Results: 20 366 pregnant women in 12 diVerent Spanish cities were tested in a 3 year period (July 1996 to August 1999). 32 samples were repeatedly reactive by ELISA, and 10 of them were confirmed as positive by western blot (eight for HTLV-II and two for HTLV-I). In addition, three of 13 women who had an indeterminate western blot pattern yielded positive results for HTLV-II by PCR. All 11 HTLV-II infected women had been born in Spain, and all but one were former drug users. Seven of them were coinfected with HIV-1. One HTLV-I infected woman was from Peru, where HTLV is endemic and where she most probably was infected during sexual intercourse. Conclusion:The overall prevalence of HTLV infection among pregnant women in Spain is 0.064% (13/20 366), and HTLV-II instead of HTLV-I is the most commonly found variant. A strong relation was found among HTLV-II infection and specific epidemiological features, such as Spanish nationality and injecting drug use. Although HTLV-II can be vertically transmitted, mainly through breast feeding, both the low prevalence of infection and its lack of pathogenicity would not support the introduction of HTLV antenatal screening in Spain. (Sex Transm Inf 2000;76:366-370)

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“…27 28 We found three HTLV-II infected women who had an indeterminate pattern on western blot. All three were Spanish natives, IDUs, and coinfected with HIV-1.…”

Section: Discussionmentioning

confidence: 86%

Prevalence of HTLV infection in pregnant women in Spain

Machuca

Tuset²,

Soriano³

et al. 2000

Sexually Transmitted Infections

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“…This approach is often accompanied by a high proportion of indeterminate WB results when low-risk populations, such as blood donors (1,10), are tested, although subsequent PCR analyses discharge the presence of HTLV-1/2 infection in almost all cases. In contrast, in high-risk populations, such as intravenous drug users (IDU), indeterminate HTLV WB patterns or even nonreactive EIA results may be seen in persons with true HTLV-2 infection (6,11). Since IDU are often coinfected with human immunodeficiency virus type 1 (HIV-1), it has been suggested that immunosuppression could explain the inability to mount and/or maintain an appropriate level of HTLV-2 antibodies, particularly in advanced stages of HIV disease (6).…”

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confidence: 99%

“…In contrast, in high-risk populations, such as intravenous drug users (IDU), indeterminate HTLV WB patterns or even nonreactive EIA results may be seen in persons with true HTLV-2 infection (6,11). Since IDU are often coinfected with human immunodeficiency virus type 1 (HIV-1), it has been suggested that immunosuppression could explain the inability to mount and/or maintain an appropriate level of HTLV-2 antibodies, particularly in advanced stages of HIV disease (6). A similar poor antibody response has been described for hepatitis C virus in HIV-positive individuals, causing "occult" infections (2).…”

mentioning

confidence: 99%

Can the Level of Immunosuppression in Human Immunodeficiency Virus-Infected Patients Affect the Reliability of Human T-Cell Lymphotropic Virus Type 2 Serological Diagnosis?

Bassani¹,

Toro²,

Jiménez³

et al. 2006

Clin Vaccine Immunol

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nosuppression, whereas PCR should be performed for subjects with a reactive HTLV EIA which is not further confirmed by WB.As with other retroviruses, the diagnosis of human T-cell lymphotropic virus type 1 (HTLV-1) or type 2 infections is generally made using serological assays that assess the presence of specific HTLV-1/2 antibodies. The recommended algorithm advises to first perform a screening enzyme immunoassay (EIA) to detect both viruses followed by Western blot (WB) testing of reactive samples to confirm infection and discriminate between HTLV-1 and HTLV-2. This approach is often accompanied by a high proportion of indeterminate WB results when low-risk populations, such as blood donors (1, 10), are tested, although subsequent PCR analyses discharge the presence of HTLV-1/2 infection in almost all cases. In contrast, in high-risk populations, such as intravenous drug users (IDU), indeterminate HTLV WB patterns or even nonreactive EIA results may be seen in persons with true HTLV-2 infection (6, 11). Since IDU are often coinfected with human immunodeficiency virus type 1 (HIV-1), it has been suggested that immunosuppression could explain the inability to mount and/or maintain an appropriate level of HTLV-2 antibodies, particularly in advanced stages of HIV disease (6). A similar poor antibody response has been described for hepatitis C virus in HIV-positive individuals, causing "occult" infections (2). Herein, we assess the impact of HIV-related immunosuppression on the performance of current serological tests used for HTLV-2 diagnosis.A large group of former IDU known to be HIV positive and on regular follow-up at our institution was analyzed. We have previously reported a high prevalence of HLTV-2 infection in this population (8). A total of 175 IDU had severe immunosuppression, with a CD4 cell count below 200 cells/l. They were matched by age, gender, and place of residence with 175 HIV-positive IDU with a preserved immune status and CD4 cell counts above 500 cells/l. Serum specimens were tested for antibodies to HTLV-1/2 using a commercial EIA (Murex HTLV IϩII; Abbott, Barcelona, Spain). Samples with repeated EIA reactivity were tested using a commercial WB (Bioblot HTLV; Genelabs, Singapore). These WB strips contain HTLV-1 viral lysate and three recombinant envelope proteins: the transmembranous HTLV gp21 (rgp21), the surface gp46 from HTLV-2 (rgp46-II), and the surface gp46 from HTLV-1 (rgp46-I). The HTLV European Research Network criteria (5) were used for interpreting WB patterns. Briefly, HTLV-2 positivity was considered when reactivity to at least two recombinant envelope bands (rgp21 and rgp46-II) and the gag band p24 was seen. HTLV-2 infection was considered negative when no bands appeared in the WB. Other WB patterns were interpreted as HTLV indeterminate.A specific HTLV-1/2 PCR was performed in all subjects with CD4 counts below 200 cells/l, as previously described elsewhere (9). Briefly, the HTLV-1/2 PCR was performed using nested primers (12P1, SK111, 12P5, 1P1, and 2P3) directed against th...

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“…In general, indeterminate WB findings do not represent current HTLV infection 33 , but in high-risk populations or in endemic areas, an indeterminate WB result may represent a case at the seroconversion stage 20,34 . By using real-time PCR in the present study, we found nine samples that were EIA-positive and WB-indeterminate, and two of them (22.2%) were positive for HTLV-1.…”

Section: Referencesmentioning

confidence: 99%

Evaluation of the use of real-time PCR for human T cell lymphotropic virus 1 and 2 as a confirmatory test in screening for blood donors

Andrade¹,

Ribeiro²,

Namen-Lopes³

et al. 2010

Rev. Soc. Bras. Med. Trop.

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Introduction: HTLV-1/2 screening among blood donors commonly utilizes an enzymelinked immunosorbent assay (EIA), followed by a confirmatory method such as Western blot (WB) if the EIA is positive. However, this algorithm yields a high rate of inconclusive results, and is expensive. Methods: Two qualitative real-time PCR assays were developed to detect HTLV-1 and 2, and a total of 318 samples were tested (152 blood donors, 108 asymptomatic carriers, 26 HAM/TSP patients and 30 seronegative individuals). Results: The sensitivity and specificity of PCR in comparison with WB results were 99.4% and 98.5%, respectively. PCR tests were more efficient for identifying the virus type, detecting HTLV-2 infection and defining inconclusive cases. Conclusions: Because real-time PCR is sensitive and practical and costs much less than WB, this technique can be used as a confirmatory test for HTLV in blood banks, as a replacement for WB.

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Significance of indeterminate reactivity to human T-Cell lymphotropic virus in Western blot analysis of individuals at risk

Cited by 19 publications

References 16 publications

Prevalence of HTLV infection in pregnant women in Spain

Prevalence of HTLV infection in pregnant women in Spain

Can the Level of Immunosuppression in Human Immunodeficiency Virus-Infected Patients Affect the Reliability of Human T-Cell Lymphotropic Virus Type 2 Serological Diagnosis?

Evaluation of the use of real-time PCR for human T cell lymphotropic virus 1 and 2 as a confirmatory test in screening for blood donors

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