Quantitation of white cell subpopulations by polymerase chain reaction using frozen whole-blood samples. Viral Activation Transfusion Study

Haptoglobin gene polymorphisms and interleukin-6 and -8 levels in patients with sickle cell anemia

Background

Haptoglobin genotypes, and interleukin-6 and -8 participate in the pathophysiology of sickle cell anemia. The expression of cytokines is regulated by genetic mechanisms however the effect of haptoglobin polymorphisms on these cytokines is not fully understood. This study aimed to compare the frequency of haptoglobin genotypes and the interleukin-6 and -8 concentrations in sickle cell anemia patients and controls to investigate the association between haptoglobin genotypes and cytokine levels.

Methods

Sixty sickle cell anemia patients and 74 healthy individuals were analyzed. Haptoglobin genotypes were determined by multiplex polymerase chain reaction, and the interleukin-6 and -8 levels by enzyme linked immunosorbent assay. The association between haptoglobin genotypes and cytokines was investigated by statistical tests.

Results

Hp2-1 was the most common genotype in both the cases and controls while Hp1-1 was less frequent among sickle cell anemia patients. Interleukin-6 and -8 levels were higher in patients than controls (p-value <0.0001). There was no significant difference in interleukin-6 and -8 concentrations between the genotypes (p-value >0.05). A similar trend was observed among the controls.

Conclusion

Although, levels of interleukin-6 and -8 were higher in the sickle cell anemia patients, they appeared not to be related to the haptoglobin genotypes. Further investigations are necessary to identify factors responsible for increased secretion of the interleukin-6 and -8 pro-inflammatory cytokines in patients with sickle cell anemia.

Molecular analysis and association with clinical and laboratory manifestations in children with sickle cell anemia

OBJECTIVES

To analyze the frequency of β(S)-globin haplotypes and alpha-thalassemia, and their influence on clinical manifestations and the hematological profile of children with sickle cell anemia.

METHOD

The frequency of β(S)-globin haplotypes and alpha-thalassemia and any association with clinical and laboratorial manifestations were determined in 117 sickle cell anemia children aged 3-71 months. The confirmation of hemoglobin SS and determination of the haplotypes were achieved by polymerase chain reaction-restriction fragment length polymorphism, and alpha-thalassemia genotyping was by multiplex polymerase chain reaction (single-tube multiplex-polymerase chain reaction).

RESULTS

The genotype distribution of haplotypes was 43 (36.7%) Central African Republic/Benin, 41 (35.0%) Central African Republic/Central African Republic, 20 (17.0%) Rare/atypical, and 13 (11.1%) Benin/Benin. The frequency of the α3.7 deletion was 1.71% as homozygous (-α3.7/-α3.7) and 11.9% as heterozygous (-α3.7/αα). The only significant association in respect to haplotypes was related to the mean corpuscular volume. The presence of alpha-thalassemia was significantly associated to decreases in mean corpuscular volume, mean corpuscular hemoglobin and reticulocyte count and to an increase in the red blood cell count. There were no significant associations of β(S)-globin haplotypes and alpha-thalassemia with clinical manifestations.

CONCLUSIONS

In the study population, the frequency of alpha-thalassemia was similar to published data in Brazil with the Central African Republic haplotype being the most common, followed by the Benin haplotype. β(S)-globin haplotypes and interaction between alpha-thalassemia and sickle cell anemia did not influence fetal hemoglobin concentrations or the number of clinical manifestations.

Association of prostate cancer susceptibility variant (MSMB) rs10993994 with risk of spermatogenic failure

β-Microseminoprotein (MSMB) is one of the most abundant proteins in human seminal plasma. It has been identified that MSMB increased significantly in oligoasthenoteratozoospermic patients compared with fertile controls. We hypothesized that the functional polymorphism (rs10993994) of MSMB gene could be a risk factor for spermatogenic failure. For this study, 338 patients with idiopathic oligozoospermia or azoospermia and 382 fertile controls were recruited from an infertility clinic. Semen analysis was performed by computer-assisted semen analysis system. The functional polymorphism of MSMB gene was genotyped using TaqMan method. Sixty three seminal plasma samples were used to test the expression of MSMB by enzyme-linked immunosorbent assay (ELISA). The TT genotype and T allele were associated with an increased risk of idiopathic infertility with azoospermia (TT genotype: OR, 1.75; 95% CI, 1.03-2.95; T allele: OR, 1.34; 95% CI, 1.03-1.75). However, no differences were found in risk for the TT genotype or T allele among men with oligozoospermia. In addition, idiopathic infertile males have significantly higher MSMB expression levels than fertile controls. We present the first epidemiologic evidence supporting the involvement of common genetic polymorphism in MSMB gene in spermatogenic failure. These results suggest that men carrying the variant have an increased risk of spermatogenic failure associated with male infertility. Further studies are needed to confirm the roles of the polymorphism in idiopathic azoospermia and investigate the biological mechanism of elevated MSMB expression in infertile males.

A miR-125b binding site polymorphism in bone morphogenetic protein membrane receptor type IB gene and prostate cancer risk in China

Recently, a C>T polymorphism (rs1434536) in a miR-125b binding site in the 3' untranslated region (3'UTR) of bone morphogenetic protein membrane receptor type IB gene (BMPR1B) has been found to contribute to cancer susceptibility. To investigate whether it plays an important role in the development of prostate cancer in southern Chinese Han population, we performed a case-control study. 247 prostate cancer and 278 control subjects were included in the cancer association study and dual-luciferase reporter assay was used to test the binding ability of miR-125b to BMPR1B-C or -T vectors. The effect of CT/TT genotype on prostate cancer risk was found to be significant for localized disease (OR=1.60, 95% CI=1.01-2.53, P=0.044) and among subgroups of aged>70 years (OR=1.90, 95% CI=1.15-3.15, P=0.015) compared with CC genotype. Moreover, C-allele gave a reduced luciferase activity relative to T-allele in dual-luciferase reporter assay. Our findings show that rs1434536 in the 3'UTR of BMPR1B gene affects the binding ability of miR-125b to BMPR1B mRNA and contributes to the genetic predisposition to localized prostate cancer and patients aged>70 years.

A functional polymorphism in MSMB gene promoter is associated with prostate cancer risk and serum MSMB expression

BACKGROUND

To explore the reported association of SNP marker rs10993994 with prostate cancer identified by two independent in two genome-wide association studies (GWAS) further, we performed a case-control study in southern Chinese Han population. Consequently, we detected the serum levels of MSMB expression with different genotypes in the cases and controls to characterize the functional consequences of rs10993994.

MATERIALS AND METHODS

Two hundred fifty-one prostate cancer and 258 control subjects were included in the cancer association study and 90 serum samples were used to test the expression of the MSMB by Enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that the T allele displayed an increased prevalence of prostate cancer compared with the C allele (OR = 1.30, 95% CI = 1.01-1.67, P = 0.040). Moreover, the prostate cancer patients carrying CT/TT genotype had significantly decreased serum MSMB levels compared to those with CC genotype (16.32 +/- 3.98 microg/L vs. 19.33 +/- 4.27 microg/L, P = 0.022).

CONCLUSIONS

rs10993994 in MSMB promoter affects serum MSMB expression, contributes to the genetic predisposition to prostate cancer in southern Chinese Han population.

Association of loss of heterozygosity with cytogenetic abnormalities in acute myeloid leukemia and myelodysplastic syndrome

Deletions on chromosomes 5 and 7 are frequently seen in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). It is assumed that these deletions indicate loss of tumor suppressor genes on these chromosomes and until these tumor suppressor genes are identified, the functional consequences of these deletions and the molecular basis of these myeloid disorders cannot be completely understood. We evaluated loss of heterozygosity (LOH) in 44 patients (18 MDS and 26 AML, diagnosed according to WHO classification criteria) at diagnosis, using a four-microsatellite marker panel: an intragenic marker on the 7th intron of gene IRF-1 of the 5q31.1 region and three markers located inside the 7q31.1 region and correlated the LOH with karyotype abnormalities. The microsatellites chosen corresponded to chromosome regions frequently deleted in MDS/AML. The samples with Q (peak area) less than or equal to 0.50 were indicative of LOH. The percent of informative samples (i.e., heterozygous) for the intragenic microsatellite in gene IRF-1 and in loci D7S486, D7S515 and D7S522 were 66.6, 73.7, 75.5, and 48.8%, respectively. Cytogenetic abnormalities by G-banding were found in 36% (16/44) of the patients (2 of 18 MDS and 14 of 26 AML patients). We found a significantly positive association of the occurrence of LOH with abnormal karyotype (P < 0.05; chi-square test) and there were cases with LOH but the karyotype was normal (by G-banding). These data indicate that LOH in different microsatellite markers is possibly an event previous to chromosomal abnormalities in these myeloid neoplasias.

Fluorescence in situ hybridization and chromosome studies after transfusion in newborns: Is a waiting period necessary?

BACKGROUND

Delaying chromosome studies after transfusion is common practice in many neonatal intensive care units (NICUs). Yet, no evidence exists to support this practice.

PURPOSE

To investigate the effects of filtration and irradiation on chromosome detection, and to evaluate donor chromosome interference after transfusion.

METHODS

Packed red blood cells (PRBCs) were evaluated by fluorescence in situ hybridization (FISH) and chromosome analyses. To evaluate donor leukocyte survival, blood was collected from female neonates who received male-donated PRBCs.

RESULTS

Irradiated, leukodepleted blood had no Y chromosome detection by FISH. Irradiated, microaggregate filtered blood had Y chromosome detection in all samples by FISH but no metaphase growth. No donor chromosomes were detected in neonates after transfusion.

CONCLUSIONS

Delaying chromosome or FISH analysis in transfused neonates who have received irradiated blood is unnecessary.

CMV DNA is rarely detected in healthy blood donors using validated PCR assays

BACKGROUND

Although serologic screening or WBC reduction of blood components can reduce the incidence of transfusion-transmitted CMV (TT-CMV) infection, 'breakthrough' cases of TT-CMV still occur and may produce serious sequelae. NAT of blood components for CMV DNA has been proposed to further reduce the risks of TT-CMV. However, large-scale studies to determine the utility of validated CMV NAT assays for donor screening have not been reported.

STUDY DESIGN AND METHODS

Coded whole-blood samples (n=1000) were tested for the presence of CMV DNA using two CMV PCR assays previously validated in a multicenter trial (a nested PCR assay directed at the CMV UL93 open-reading frame and the Roche Monitor assay). Corresponding plasma samples were tested in parallel for the presence of anti-CMV using other assays (Abbott CMV EIA and Fujirebio/Olympus CMV particle agglutination assays).

RESULTS

In total 416 and 514 of the samples tested as CMV-seropositive and -seronegative, respectively, by both antibody assays. The remaining 70 samples had discrepant serology results. Only 2 of the 1000 samples (both seropositive) had reproducibly detectable CMV DNA (positive in at least three of four replicates). CMV DNA was not reproducibly detected in seronegative samples or in samples with discrepant serology results.

CONCLUSIONS

Although previous investigations showed frequent detection of CMV DNA in healthy CMV-seropositive (and some seronegative) blood donors, these studies were relatively small and the performance characteristics of their assays were difficult to evaluate. In contrast, the present large cross-sectional study of US donors utilized two previously validated PCR assays and demonstrated that CMV DNA is only rarely detectable in seropositive donors. Thus, the use of CMV PCR assays with optimal performance characteristics did not increase the detection of potentially infectious blood components beyond that provided by current serologic screening assays.

Fetal cells and DNA in maternal blood

Although fetal cells have been known to escape to the maternal circulation for a number of years, research attempts to use them for prenatal diagnosis have not had any consistent success. This review attempts to trace the history of such attempts and to document their progress and reasons for success or failure. The opinions of recent conferences including that of the US National Institute of Child Health and Human Development, a sponsor of major US research in the field, are reported and discussed. It is concluded that although basic work has demonstrated the biologic availability of both fetal cells and their free DNA representatives in the maternal circulation at gestational ages relevant to prenatal diagnosis, much work remains to develop practical technology for their consistent recovery and assay.

Signs and symptoms associated with the transfusion of WBC-reduced RBCs and non-WBC-reduced RBCs in patients with anemia and HIV infection: results from the Viral Activation Transfusion Study

BACKGROUND

RBC transfusion is associated with fever and other reactions in some patients. The Viral Activation Transfusion Study randomly assigned patients to receive either unmodified or WBC-reduced RBCs and thus offered an opportunity to assess the effect of WBC-reduced RBCs on the incidence of transfusion reactions prospectively.

STUDY DESIGN AND METHODS

This prospective, randomized, double-blind, multicenter study compared prestorage WBC-reduced RBCs to unmodified RBCs in HIV-infected, CMV-seropositive, and transfusion-naive persons who required transfusions for anemia. Primary endpoints were survival and change in the plasma HIV RNA level at 7 days after transfusion. The incidence of transfusion reactions was prospectively evaluated.

RESULTS

The two groups had similar baseline characteristics and study endpoints; 3864 RBC units (median storage age, 9 days) were administered to 531 patients during 1745 transfusions. The most frequent signs reported were elevated temperature and hypotension. Subjects who reported fever within the week prior to transfusion were more likely to have an elevation in temperature associated with transfusion. The administration of RBCs that were less than 10 days old was associated with a marginal increase in the incidence of transfusion-associated temperature elevation among recipients of unmodified RBCs, but not among recipients of WBC-reduced RBCs. Caregivers reported fewer instances of both elevated temperature and hypotension than were identified by review of transfusion records.

CONCLUSIONS

The incidence of elevated temperature and hypotension associated with transfusion in this population was unexpectedly high. Use of WBC-reduced RBCs had no effect on the overall rates of elevated temperature or hypotension associated with transfusion of RBCs. The occurrence of a pre-existing fever was associated with a higher frequency of transfusion-associated elevated temperature.

Quantitation of residual WBCs in filtered blood components by high-throughput, real-time kinetic PCR

BACKGROUND

The effort to eliminate transfusion complications associated with WBCs has led to the widespread use of filters able to reduce WBC concentrations to <or=0.1 WBC per microL blood. This has necessitated sensitive QC methods to quantitate residual WBCs in filtered units. One fast, effective method is DNA amplification using real-time kinetic PCR (kPCR).

STUDY DESIGN AND METHODS

Two methods of preparation of standards were compared and used for the optimization of quantitative kPCR. The first involved spiking genomic DNA cell lysate into a diluent, followed by a series of 1 in 10 dilutions. The second involved spiking serial 1 in 10 dilutions of WBCs into twice-filtered fresh whole blood. Two hundred fifty filtered frozen whole-blood samples were amplified in duplicate to show the kPCR assay's reproducibility. Another 359 filtered frozen whole blood samples were used to compare data from kPCR with data from a standard PCR protocol using (32)P-labeled probe and autoradiography. All specimens were amplified for conserved HLA DQ(alpha) sequences.

RESULTS

Standards prepared by both methods gave reproducible and equivalent results. Quantitation of standards representing a dynamic range of 8 x 10(o) to 8 x 10(5) WBCs per mL, yielded standard deviations ranging from 0.59 cycle to 1.04 cycles (a one-cycle increase is equivalent to a twofold increase in WBC concentration). The scatter graph of the 250 samples tested in duplicate by kPCR generated a slope of 1.0122 and an R(2) value of 0.9265. The comparison of kPCR and (32)P-probe hybridization results on 359 clinical samples gave a scatter-graph slope of 0.9428 and an R(2) value of 0.8718, indicating excellent agreement of the methods over a 4-log dynamic range.

CONCLUSION

kPCR is a high-throughput, sensitive assay that could prove useful in routine quality assurance of the WBC reduction process.

Residual subset population analysis in WBC-reduced blood components using real-time PCR quantitation of specific mRNA

BACKGROUND

Implementation of WBC reduction of the blood supply increases the importance of measurement of residual WBC subtypes responsible for immunologic and infectious complications of transfusion.

STUDY DESIGN AND METHODS

Real-time RT-PCR assays were developed to detect mRNA encoding lineage-specific WBC markers. Primers and fluorescent probes were designed for CD45 (pan-WBC), CD3 (T-lymphocyte), CD19 (B-lymphocyte), CD14 (monocyte), and CD66 (granulocyte), and the specificity was assessed by comparison with flow cytometric analysis of enriched cell populations. WBC subsets were examined in WBC-reduced whole blood prepared with filters (WBF2, Pall; and RZ2000, Baxter) and in platelet concentrates prepared with other filters (Autostop, Pall; and PLX-5, Baxter) and apheresis (COBE Spectra LRS, Gambro).

RESULTS

All real-time RT-PCR assays were linear over >5 log concentration range, allowing pre-WBC-reduction and post-WBC-reduction comparisons. Sensitivity limits ranged from 10 cells per mL (CD45) to 200 cells per mL (CD19). Assay specificity was confirmed by the close correlation of real-time RT-PCR and immunophenotyping results by flow cytometry. For all subsets, >3.8 log and >3.1 log reduction was obtained during WBC reduction of whole blood and platelets, respectively.

CONCLUSION

Real-time RT-PCR assays are suitable for analysis of subset removal during WBC reduction. There was no significant difference between the two whole-blood filters or between platelet filtration and apheresis in the removal of any WBC subset.

Kinetics of fetal cellular and cell-free DNA in the maternal circulation during and after pregnancy: implications for noninvasive prenatal diagnosis

BACKGROUND

Fetal genetic material is detectable in the maternal circulation and has been used for noninvasive prenatal diagnosis. However, few data are available concerning its quantity and natural history during gestation.

STUDY DESIGN AND METHODS

This study prospectively characterized the kinetics of cellular and cell-free fetal DNA in the circulation of 25 healthy women during and after uncomplicated pregnancy. Real-time kinetic PCR was used to quantitate human Y-chromosome sequences, and liquid oligomer hybridization with (32)P-labeled probes was used to verify the identity of amplified products.

RESULTS

In all male pregnancies, but no female pregnancies, low-level fetal Y-chromosome DNA was detected in both cellular and cell-free compartments beginning at 7 to 16 weeks but increasing steadily after 24 weeks and reaching a peak at parturition. The fetal DNA decreased rapidly after birth.

CONCLUSION

Fetal genetic material can be detected throughout pregnancy, and its quantity is a function of gestational age and of whether the plasma or cellular compartment is examined. Both the absolute quantity of fetal DNA and its ratio to total DNA (maternal + fetal) are greater in the plasma than in the cellular compartment. Fetal DNA is cleared rapidly from both compartments after parturition, which suggests that turnover is dynamic. Because they provide prospective and quantitative data concerning fetal DNA levels, these observations and kinetic PCR methods may have implications for noninvasive prenatal diagnosis. Further studies will be needed to determine the immunologic implications of fetal-maternal DNA exchange and cellular microchimerism.

Multicenter evaluation of PCR methods for detecting CMV DNA in blood donors

BACKGROUND

CMV DNA screening may be a useful adjunct to serologic tests in distinguishing potentially infectious blood donations from those that are "CMV-safe." However, there is currently no consensus on the optimal assay method for accurate detection of CMV DNA in donors.

STUDY DESIGN AND METHODS

A blinded multicenter evaluation of seven CMV PCR assays was performed by five laboratories by using coded sets of analytical controls and donor blood samples.

RESULTS

Five assays displayed sufficient sensitivity for donor screening, as judged by consistent detection of a minimum of 25 CMV genome equivalents (geq) in analytical controls constructed to contain from 1 to 100 CMV geq in background DNA from 250,000 cells, while the other two assays displayed inadequate sensitivity. Three sensitive assays, two based on nested PCR directed at the UL93 and UL32 regions of the CMV genome and another test (Monitor Assay, Roche), did not detect CMV DNA in samples from any of 20 pedigreed CMV-seronegative, Western blot-negative (S-/WB-) donors. Two other assays based on nested PCR occasionally detected CMV DNA in S-WB- samples, and one sensitive nested PCR assay directed at UL123 detected CMV DNA in a large proportion (85%) of S-WB- samples.

CONCLUSION

Seven CMV PCR assays currently used for research and/or diagnostic applications displayed marked variations in sensitivity, specificity, and reproducibility when applied to coded analytical and clinical control samples containing cellular DNA from the equivalent of 250,000 WBCs. These results will be useful in the selection of assays with performance characteristics appropriate to donor screening objectives. They may also help explain discrepant findings from previous studies that used PCR to determine CMV DNA prevalence in seronegative and seropositive blood donors.

WBC reduction in RBC concentrates by prestorage filtration: multicenter experience

BACKGROUND

As universal leukocyte (WBC) reduction (ULR) is being considered as a new standard, few data are available on the performance of WBC-reduction filtration in routine practice. The performance of WBC-reduction in RBCs, using varied filtration practices, in meeting the current FDA requirement (<5 x 10(6)), Council of Europe (EC) recommendation, the proposed FDA requirement (<1 x 10(6)), and a more stringent proposal (<5 x 10(5)) for residual WBCs per RBC unit was assessed and compared.

STUDY DESIGN AND METHODS

Participating facilities were the 11 sites of the Viral Activation Transfusion Study (VATS), a prospective study of the impact of transfusion with and without WBC-reduction on survival and HIV viral load in HIV-1-infected patients. Patients randomly assigned to undergo WBC reduction were required to receive RBCs < or =14 days old that had undergone prestorage (within 72 hours of collection) WBC-reduction filtration by a method devised to achieve a postfiltration WBC count of <5 x 10(6). Residual WBC quantitation was performed by PCR in the central VATS laboratory by using frozen WBC-reduced RBC samples obtained at issue for transfusion.

RESULTS

A total of 1869 WBC-reduced RBC units were studied. Filtration practices varied within and between sites. There were significant differences in mean residual WBC counts at the 11 sites (p<0.001). Among the WBC-reduced RBC units, 0.8 percent exceeded 5 x 10(6) WBCs per unit, 8.3 percent exceeded 1 x 10(6) WBCs per unit, and 14.3 percent exceeded 5 x 10(5) WBCs per unit.

CONCLUSION

Residual WBCs in WBC-reduced RBC units vary within and between sites. WBC reduction was successful, in that over 99 percent and 91 percent of VATS WBC-reduced RBC units met US and EC thresholds, respectively. However, the small but measurable failure rate indicates that not every unit will meet these guidelines.

Survival of transfused donor white blood cells in HIV-infected recipients

The appearance and expansion of donor white blood cells in a recipient after transfusion has many potential biologic ramifications. Although patients with HIV infection are ostensibly at high risk for microchimerism, transfusion-associated graft-versus-host disease (TA-GVHD) is rare. The purpose of this study was to search for sustained microchimerism in such patients. Blood samples were collected from 93 HIV-infected women (a subset from the Viral Activation Transfusion Study, an NHLBI multicenter randomized trial comparing leukoreduced versus unmodified red blood cell [RBC] transfusions) before and after transfusions from male donors. Donor lymphocytes were detected in posttransfusion specimens using a quantitative Y-chromosome-specific polymerase chain reaction (PCR) assay, and donor-specific human leukocyte antigen (HLA) alleles were identified with allele-specific PCR primers and probes. Five of 47 subjects randomized to receive nonleukoreduced RBCs had detectable male lymphocytes 1 to 2 weeks after transfusion, but no subject had detectable male cells more than 4 weeks after a transfusion. In 4 subjects studied, donor-specific HLA haplotypes were detected in posttransfusion specimens, consistent with one or more donors' cells. None of 46 subjects randomized to receive leukoreduced RBCs had detectable male lymphocytes in the month after transfusion. Development of sustained microchimerism after transfusion in HIV-infected patients is rare; HIV-infected patients do not appear to be at risk for TA-GVHD.

Donor WBCs can persist and transiently mediate immunologic function in a murine transfusion model: effects of irradiation, storage, and histocompatibility

BACKGROUND

Donor WBCs are responsible for numerous transfusion complications, but little is known concerning the natural history of their clearance following transfusion or of their function in the recipient's circulation. A murine transfusion model was developed to investigate the effects of blood component characteristics and histocompatibility on donor WBC survival kinetics and function.

STUDY DESIGN AND METHODS

To investigate the effects of storage and irradiation, fresh whole blood and blood stored for 1, 2, and 6 weeks at 4 degrees C, all from male C57b (H2K(b)) mice, was transfused to female Balb/c (H2K(d)) mice. To study the effect of histocompatibility, blood was also transfused from C57b mice to Balb/c, FVB, C3H, and SW (outbred) mice. To investigate the xenogeneic setting, blood from humans, rats, and rabbits was transfused to Balb/c mice. Samples were collected weekly after transfusion, and the donor WBCs were analyzed, targeting the Y-chromosome with quantitative PCR. To investigate donor WBC function, dinitrochlorobenzene (DNCB) sensitivity was induced in donor and recipient mice, and the transfusion recipients were observed for hypersensitivity to DNCB.

RESULTS

Donor WBCs had reduced in vivo survival equivalent to their period of storage ex vivo at 4 degrees C. Irradiation of donor blood produced no observable difference in donor WBC survival. Allogeneic male donor WBCs persisted (100-<1 cell/microL) in female Balb/c recipient mice blood over 6 weeks. Donor WBC survival kinetics displayed an early MHC-dependent phase, which was followed by a more rapid phase that was not influenced by donor-recipient MHC differences. All donor WBCs were cleared within 24 to 48 hours. DNCB sensitivity was passed through transfusion, where it was transiently expressed in naive recipients.

CONCLUSION

The clearance of donor WBCs in the murine transfusion model is much slower than that in humans. Allogeneic donor WBC clearance may be biphasic, involving MHC-dependent as well as MHC-independent mechanisms. DNCB sensitivity can be transferred transiently to a naive recipient.

Human T-lymphotropic virus type II RFLP subtypes a0 and b4/b5 are associated with different demographic and geographic characteristics in the United States

Human T-lymphotropic virus type II (HTLV-II) prevalence is very low among the general U.S. population, intermediate among American Indians, and high among injecting drug users and their sexual partners. However, the transmission dynamics underlying this distribution are not well described. We obtained blood specimens from 493 blood donors found to be seropositive for HTLV-II at blood centers in five U.S. cities. Nested polymerase chain reaction was used to amplify a 672-bp region of the HTLV-II long terminal repeat region, and restriction fragment length polymorphism (RFLP) analysis was performed to classify each virus into subtypes as defined by Switzer et al. (1995, J. Virol. 69, 621-632). Associations between RFLP subtype and other characteristics were analyzed using multivariable logistic regression. HTLV-II subtype a0 was independently associated with age over 30 years (odds ratio (OR) = 2.12, 95% confidence interval (CI) 1.13-3.99) and with Black race/ethnicity (OR = 2.00, 95% CI 1.10-3.65 versus Hispanic race/ethnicity). Conversely, HTLV-II RFLP subtypes b4 and b5 were significantly more common among American Indian (OR = 3.77, 95% CI 1.23-11.57) and Other race/ethnicity (OR = 4.22, 95% CI 1.25-14.27, both versus Black race/ethnicity) and at the Oklahoma City blood center (OR = 3.57, 95% CI 1.08-11.84 compared to Washington, DC/Baltimore). There may have been at least two transmission foci of HTLV-II in the United States: a modest HTLV-II subtype a0 epidemic of unknown source in the 1960s and 1970s spread predominantly among Black persons in several geographic areas and a smaller focus of HTLV-II subtypes b4/b5 among non-Black individuals in Oklahoma and perhaps in other areas not examined by this study.

Determinants of antimicrobial prophylaxis use and treatment for wasting among patients with advanced human immunodeficiency virus disease in the United States, 1995-1998

Despite US Public Health Service (USPHS) recommendations for antimicrobial prophylaxis for patients with advanced human immunodeficiency virus (HIV) disease, the proportion of patients who receive prophylaxis is not known. We measured the prevalence of antimicrobial prophylaxis use, and treatment for HIV wasting at baseline among 531 patients with advanced HIV disease enrolled in a multicenter randomized trial of red blood cell transfusion. Use of antimicrobial prophylaxis and treatment for wasting in the 30 days before enrollment was ascertained in patients eligible for primary prophylaxis, secondary prophylaxis, or both, according to USPHS guidelines. There was high utilization of primary and secondary Pneumocystis carinii pneumonia prophylaxis, variability in primary Mycobacterium avium complex prophylaxis by center, and low use of primary cytomegalovirus prophylaxis. Treatment of wasting was more common in white than nonwhite patients and in patients with HIV disease who lived in the region west of the Mississippi River of the United States versus those whose lived in the eastern region.

Survival of Donor Leukocyte Subpopulations in Immunocompetent Transfusion Recipients: Frequent Long-Term Microchimerism in Severe Trauma Patients

We recently reported detection of a transient increase in circulating donor leukocytes (WBCs) in immunocompetent recipients 3 to 5 days posttransfusion (tx) (Blood 85:1207, 1995). We have now characterized survival kinetics of specific donor WBC subsets in additional tx populations. Eight female elective surgery patients (pts) were sampled pre-tx and on days 1, 3, 5, 7, and 14 post-tx. Ten female trauma pts transfused with a total of 4 to 18 U of relatively fresh red blood cells were sampled up to 1.5 years post-tx. WBC subsets from frozen whole blood were isolated using CD4, CD8 (T cell), CD15 (myeloid), and CD19 (B cell) antibody-coated magnetic beads. Donor WBCs were counted by quantitative polymerase chain reaction (PCR) of male-specific sex determining region (SRY) sequences. PCR HLA typing and mixed leukocyte reaction (MLR) between recipient and donor WBCs were performed on two of the trauma tx recipients who had long-term chimerism of donor cells post-tx. In 6 of 8 female surgery pts, circulating CD4+ male donor cells peaked at day 3 or 5 (0.01 to 1 cell/μL), followed by clearance by day 14. In 7 of 10 female trauma pts, we observed multilineage persistence of male donor WBCs (CD4, CD8, CD15, CD19) for 6 months to 1.5 years post-tx at concentrations of 10 to 100 cells/μL. In 2 trauma recipients studied, MLR showed no, or very low, response to WBC of the single donor implicated as the source of microchimerism by HLA typing. Establishment of long-term multilineage chimerism in trauma recipients is probably caused by engraftment of donor stem cells and mutual tolerance between recipient and donor leukocytes. A better understanding of factors determining clearance versus chimerism of transfused leukocytes is critical to prevention of alloimmunization and transfusion-induced graft-versus-host disease, and, potentially, to induction of tolerance for transplantation.

Survival of Donor Leukocyte Subpopulations in Immunocompetent Transfusion Recipients: Frequent Long-Term Microchimerism in Severe Trauma Patients

We recently reported detection of a transient increase in circulating donor leukocytes (WBCs) in immunocompetent recipients 3 to 5 days posttransfusion (tx) (Blood 85:1207, 1995). We have now characterized survival kinetics of specific donor WBC subsets in additional tx populations. Eight female elective surgery patients (pts) were sampled pre-tx and on days 1, 3, 5, 7, and 14 post-tx. Ten female trauma pts transfused with a total of 4 to 18 U of relatively fresh red blood cells were sampled up to 1.5 years post-tx. WBC subsets from frozen whole blood were isolated using CD4, CD8 (T cell), CD15 (myeloid), and CD19 (B cell) antibody-coated magnetic beads. Donor WBCs were counted by quantitative polymerase chain reaction (PCR) of male-specific sex determining region (SRY) sequences. PCR HLA typing and mixed leukocyte reaction (MLR) between recipient and donor WBCs were performed on two of the trauma tx recipients who had long-term chimerism of donor cells post-tx. In 6 of 8 female surgery pts, circulating CD4+ male donor cells peaked at day 3 or 5 (0.01 to 1 cell/μL), followed by clearance by day 14. In 7 of 10 female trauma pts, we observed multilineage persistence of male donor WBCs (CD4, CD8, CD15, CD19) for 6 months to 1.5 years post-tx at concentrations of 10 to 100 cells/μL. In 2 trauma recipients studied, MLR showed no, or very low, response to WBC of the single donor implicated as the source of microchimerism by HLA typing. Establishment of long-term multilineage chimerism in trauma recipients is probably caused by engraftment of donor stem cells and mutual tolerance between recipient and donor leukocytes. A better understanding of factors determining clearance versus chimerism of transfused leukocytes is critical to prevention of alloimmunization and transfusion-induced graft-versus-host disease, and, potentially, to induction of tolerance for transplantation.