Discrepancy between human T-cell lymphotropic virus type I screening test and confirmatory tests in non-endemic areas

Natural Course of Human T-Cell Leukemia Virus Type 1 Proviral DNA Levels in Carriers During Pregnancy

The measurement of human T-cell leukemia virus type 1 (HTLV-1) proviral DNA levels by using polymerase chain reaction has been beneficial for confirming HTLV-1 infection during pregnancy. However, the influence of pregnancy on HTLV-1 infection and proviral DNA levels among pregnant women with HTLV-1 has not been clarified. We prospectively gathered blood samples from 36 pregnant women in whom HTLV-1 carriage was previously diagnosed and sequentially measured their proviral DNA levels. The HTLV-1 proviral DNA levels remained at a plateau during pregnancy but were elevated after delivery. Moreover, flow cytometry and serological analyses revealed that the regulatory T-cell population and soluble interleukin 2 receptor levels were similarly elevated after birth in comparison with those in control pregnant women. This study is the first to provide data on sequential changes in HTLV-1 proviral DNA levels during and after pregnancy. These findings will guide the establishment of a better program to prevent mother-to-child transmission of HTLV-1.

Influence of human T-lymphotropic virus type 1 coinfection on the development of hepatocellular carcinoma in patients with hepatitis C virus infection

BACKGROUND

Human T-lymphotropic virus type 1 (HTLV-1) may worsen the clinical course of hepatitis C virus (HCV) infection. The aim of this study was to investigate whether HTLV-1 coinfection influences the clinical characteristics of patients with HCV infection.

METHODS

This retrospective study included 523 consecutive patients from January 2001 to December 2010 with chronic liver disease due to HCV infection, in whom serum anti-HTLV-1 antibodies were examined. Among these patients, 265 were diagnosed with hepatocellular carcinoma (HCC).

RESULTS

The seroprevalence of anti-HTLV-1 antibodies was significantly higher in patients with HCC (21.1%) than those without HCC (10.5%, P = 0.001). This significant difference was observed in female patients (29.5 vs. 8.5%, P < 0.001), but not in male patients (16.5 vs. 12.9%, P = 0.501). In multivariate analysis, anti-HTLV-1 antibody positivity was independently associated with HCC in female patients [odds ratio (OR), 5.029; 95% confidence interval (95% CI), 1.760-14.369; P = 0.003], in addition to age (≥65 years; OR, 10.297; 95% CI, 4.322-24.533; P < 0.001), platelet count (<15 × 10(4)/μL; OR, 2.715; 95% CI, 1.050-7.017; P = 0.039), total bilirubin (≥1 mg/dL; OR, 3.155; 95% CI, 1.365-7.292; P = 0.007), and total cholesterol (≤160 mg/dL; OR, 2.916; 95% CI, 1.341-6.342; P = 0.007). In contrast, HTLV-1 coinfection was not associated with HCC in male patients, although age, alcohol consumption, platelet count, and albumin were independently associated with HCC.

CONCLUSIONS

HTLV-1 coinfection may contribute to the development of HCC in patients with chronic HCV infection, especially in females.

Human T-lymphotropic virus laboratory testing of maternal blood at time of cord blood donations and clinical implications

BACKGROUND

In the United States, blood products are tested for infectious diseases including human T-lymphotropic virus (HTLV)-I/II. Positive results of maternal blood samples at the time of cord blood (CB) donation must be reported to mother and physician. Tests for HTLV have a high false-positive rate. This is problematic because there is no prenatal testing of the mother.

STUDY DESIGN AND METHODS

This study involves 119,769 maternal blood samples at time of CB donation and evaluates positive results for HTLV in screening tests, supplemental immunoassays, and nucleic acid tests (NATs). Infectious disease markers (IDMs) and maternal health histories of HTLV-positive and -negative mothers were compared.

RESULTS

Of 119,769 mothers donating CB, 545 tested positive with the screening test, 33 were positive with the supplemental tests, and two were positive with NAT. When indeterminate results were excluded from the supplemental test only six were positive. Eight of 34 mothers with positive or indeterminate supplemental test results had received intravenous immunoglobulin. There were no significant differences between HTLV-positive and -negative mothers with regard to the incidence of other IDMs.

CONCLUSIONS

Testing maternal blood for HTLV is problematic for CB banks, obstetricians, and mothers because of the high false-positive rate. CB banks need rapid turnaround time and supplemental testing. If results on the latter are positive the obstetrician should be notified, educated, do follow-up testing, and counseling. Indeterminate results on supplemental tests are most likely false positives. We recommend that mothers with positive or indeterminate supplemental test results have follow-up NAT.