Analysis of HTLV-1 proviral load (PVL) and antibody detected with various kinds of tests in Japanese blood donors to understand the relationship between PVL and antibody level and to gain insights toward better antibody testing.

Adult T-cell leukemia/lymphoma (ATL) occurs in approximately 5% of individuals infected with human T-cell leukemia virus type 1 (HTLV-1). A high proviral load (PVL; more than four copies per 100 peripheral blood mononuclear cells (PBMCs) or 1.6 copies per 100 blood leukocytes) and being male are risk factors for ATL development. Whether anti-HTLV-1 antibody level is related to such risk is unknown. Here, PVL and antibody levels were examined using real-time PCR and other tests in 600 HTLV-1 positive screened Japanese blood donors to understand the relationship between PVL and antibody level in asymptomatic carriers and to gain insights toward better antibody testing for HTLV-1 infection. The 430 donors in whom proviral DNA was detected were considered as true positives for HTLV-1 infection. Among donors aged 40 years or older, more males than females had a PVL corresponding to more than 1.6% infected leukocytes, and an antibody titer below the median (P = 0.0018). In antibody tests using an HTLV-1 positive cell line or Env antigens there was a large discrepancy in antibody titer among 13 provirus-positive samples, probably suggesting that antibody-based screening tests should incorporate multiple HTLV-1 antigens, such as Gag and Env antigens.

Hemodynamic response during standing test after blood donation can predict the late phase vasovagal reaction.

A major complication of blood donation is vasovagal reaction (VVR) with or without syncope. VVR occurs not only in the early phase, but also in the late phase after blood donation. We previously reported the hemodynamic characteristics of blood donors susceptible to early phase VVR. In the present study, we investigated the hemodynamic characteristics of those who developed late VVR. Ninety-six healthy volunteers donating 400 ml of whole blood were studied. After asking about their physical condition or routine questions for blood donation, blood pressure (BP) and heart rate (HR) were recorded while the donors were kept standing up for 3 min before and after blood collection. Questionnaires were distributed to all donors for reporting late VVR symptoms within 24 h. Those with younger age and lower diastolic blood pressure were more susceptible to late VVR (both p < 0.05). Furthermore, we identified the increase in HR during the standing test after blood collection as a good predictor of late VVR (odds ratio 1.063, 95 % CI 1.005-1.124; p = 0.031). Also, analysis of questions asked before donation revealed that significantly more donors considered themselves as sensitive to pain in the late VVR group (Odds ratio 0.070, 95 % CI 0.008-0.586; p = 0.014). Excessive HR response to standing after blood collection and subjective sensitivity to pain as well as younger age and lower diastolic BP may be useful to detect donors at high risk for late VVR.

Simple standing test predicts and water ingestion prevents vasovagal reaction in the high-risk blood donors.

BACKGROUND: One of the serious complications of blood donation is vasovagal reaction (VVR) with syncope. This study was performed to determine if the measurement of hemodynamic responses to standing before blood collection (BC) was useful to identify the high-risk donors for VVR and also examined the effect of 300 mL of water ingestion in the prevention of VVR. STUDY DESIGN AND METHODS: Blood pressure and heart rate (HR) during 5 minutes of standing were examined before and after BC in 93 donors. Because HR increase of 6 of 7 donors who developed syncopal VVR during standing after BC was 15 beats per minute (bpm) or greater, those with HR increase of 15 bpm or greater were determined as high-risk donors (n = 31). In another group (n = 117), 45 donors were identified as high risk based on the HR response before BC (15 bpm). The effect of 300 mL of water ingestion 15 minutes before BC on hemodynamic responses to standing and the rate of VVR after BC were analyzed. RESULTS: Water ingestion given to the high-risk donors of the second group reduced HR increase with standing before BC (-6.6 ± 13.6 bpm, p < 0.02 vs. HR increase before water ingestion) and significantly suppressed VVR rate (2 of 45 donors with high risk, 4.4%,p < 0.04 vs. the first group; 6 of 31 high-risk donors, 19.4%). CONCLUSION: HR response to standing before BC may detect the high-risk donors for VVR. For the high-risk donors, 300 mL of water ingestion may be a simple and effective way of prevention against syncopal VVR.