Increased Levels of Circulating Endothelial Progenitor Cells in Human T-cell Lymphotropic Virus Type I Carriers

Background and Aims. HTLV-I-transformed T cells secrete biologically active forms of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF). In addition, HTLV-I-transformed cells have a high capacity of adhesion to endothelial cells. Methods. We measured the circulating endothelial progenitor cells (EPCs) and mature endothelial cells (MECs) by flow cytometry in 27 HTLV-I carriers in comparison to 30 healthy, age- and gender-matched subjects. All subjects had HTLV-I positivity confirmed by Western blot and/or polymerase chain reaction (PCR). The numbers of different subpopulations of EPCs and MECSs were evaluated by four-color flow cytometry using a panel of monoclonal antibodies. All reactions were done in duplicate to confirm reproducibility of the results. Results. The median age of all 27 HTLV-I carriers enrolled in this study was 45 years (range: 27-65 years); 11(41%) were male and 16 (59%) were female. The median age of the 30 healthy subjects in the control group was 45.5 years (range: 20-63 years); 11 (36.6%) were male and 19 (63.4%) were female. The number of EPCs was significantly higher in HTLV-I carriers (median 0.8288 cells/mu L, range: 0.0920-3.3176 cells/mu L) as compared to control group (median 0.4905 cells/mu L, range: 0.0000-1.5660 cells/mu L) (p = 0.035). In contrast, the median of the MECs in the HTLV-I carriers was 0.6380 cells/mu L (range: 0.0473-5.7618 cells/mu L) and 0.4950 cells/mu L (range: 0.0000-4.0896 cells/mu L) in the control group, with no statistical difference (p = 0.697). Conclusions. We demonstrated that EPCs, but not MECs, are increased in the peripheral blood of HTLV-I carriers. (C) 2011 IMSS. Published by Elsevier Inc.

Autoimmune hemolytic anemia in systemic lupus erythematosus: association with thrombocytopenia

Hematological disturbances are common in systemic lupus erythematous (SLE). Specifically, autoimmune hemolytic anemia (AHA) may manifest in SLE patients at the time of diagnosis or within the first year of the disease. AHA is often associated with thrombocytopenia, lupus nephritis, and central nervous system activity. In this study we investigated these associations in Brazilian patients with SLE. Forty-four consecutive SLE patients who had a history of AHA were age, gender, and disease duration matched with 318 SLE patients without AHA who formed the control group. All patients fulfilled the revised American College of Rheumatology criteria for SLE and were followed-up within our Service. Clinical and laboratorial manifestations were similar in both groups, except for the predominance of leukopenia, thrombocytopenia, and anti-dsDNA on univariate analysis in the AHA group. The multivariate logistic regression model revealed risk only for thrombocytopenia in the AHA group compared to the control group (odds ratio, 2.70; 95% confidence interval, 1.32-5.50). Our results corroborate previous data that AHA in SLE increases the risk of thrombocytopenia in individuals with SLE. This association suggests a common mechanism in AHA and SLE pathophysiologies.

Whole-Genome Characterization of Human and Simian Immunodeficiency Virus Intrahost Diversity by Ultradeep Pyrosequencing

Rapid evolution and high intrahost sequence diversity are hallmarks of human and simian immunodeficiency virus (HIV/SIV) infection. Minor viral variants have important implications for drug resistance, receptor tropism, and immune evasion. Here, we used ultradeep pyrosequencing to sequence complete HIV/SIV genomes, detecting variants present at a frequency as low as 1%. This approach provides a more complete characterization of the viral population than is possible with conventional methods, revealing low-level drug resistance and detecting previously hidden changes in the viral population. While this work applies pyrosequencing to immunodeficiency viruses, this approach could be applied to virtually any viral pathogen.

Real-time quantitative PCR in cerebral toxoplasmosis diagnosis of Brazilian human immunodeficiency virus-infected patients

Cerebral toxoplasmosis is the most common cerebral mass lesion in AIDS patients in Brazil, and results in high mortality and morbidity, despite free access to HAART (highly active antiretroviral treatment). Molecular diagnosis based on conventional PCR (cnPCR) or real-time quantitative PCR (qrtPCR) has been indispensable for definitive diagnosis. We report here the evaluation of qrtPCR with blood and cerebrospinal fluid (CSF) samples from AIDS patients in Brazil. This prospective study was conducted for 2 years, analysing DNA samples extracted from 149 AIDS patients (98 blood and 51 CSF samples) with confirmed clinical and radiological diagnosis The laboratory diagnosis included cnPCR (with the B22/B23 primer set) and indirect immunofluorescence (IF). For qrtPCR, two primer sets were simultaneously designed based on described genes and using a 6-carboxyfluorescein dye-labelled TaqMan MGB (minor groove binder) probe One was Bug, which amplified a sequence from the B1 gene The other was the RETg, which amplified a PCR product of the 529 bp sequence. The overall cnPCR and qrtPCR results were positive results were observed in 33.6% (50) patients The sensitivities were 98% for cnPCR (B22/B23), and 86 and 98% for qrtPCR (B1Tg and RETg, respectively). Negative reactions were observed in 66 4% patients. The specificities were 97% for cnPCR and qrtPCR (B1Tg). and 88.8% for RETg These data show that RETg PCR is highly sensitive as it amplifies a repeat region with many copies; however, its specificity is lower than the other markers However, B1Tg PCR had good specificity, but lower sensitivity Among the patients, 20 had blood and CSF collected simultaneously Thus, their results permitted us to analyse and compare molecular, serological and clinical diagnosis for a better understanding of the different scenarios of laboratorial and clinical diagnosis. For nine patients with confirmed cerebral toxoplasmosis diagnosis, four scenarios were observed: (i) and (ii) negative molecular diagnosis for CSF and positive for blood with variable IF titres for the sera and CSF (negative or positive), (iii) positive molecular diagnosis with CSF and negative with blood, and (iv) positive molecular diagnosis in both samples. In the latter two situations, normally the IF titres in sera and CSF are variable. Other opportunistic infections were shown in 11 patients Despite the IF titres in sera and CSF being variable, all of them had negative molecular diagnosis for both samples qrtPCR allows for a rapid identification of Toxoplasma gondii DNA in patient samples; in a minority of cases discrepancies occur with the cnPCR.

Multiple Clinical Presentations of Lymphoproliferative Disorders in Pediatric Liver Transplant Recipients: A Single-Center Experience

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication following solid organ transplantation that has been linked to Epstein-Barr virus (EBV) infection. The aim of this article was to describe a single-center experience with the multiplicity of clinical presentations of PTLD. Among 350 liver transplantations performed in 303 children, 13 survivor children displayed a histological diagnosis of PTLD (13/242 survivors; 5.4%). The age at diagnosis ranged from 12 to 258 months (median, 47), and the time from transplantation ranged from 1 to 84 months (median, 13). Ten of these children (76.9%) were EBV-naive prior to transplantation. Fever was present in all cases. The clinical signs at presentation were anemia (92.3%), diarrhea and vomiting (69.2%), recurrent upper airway infections (38.4%), Waldeyer ring lymphoid tissue hypertrophy (23.0%), abdominal mass lesions (30.7%), massive cervical and mediastinal adenopathy (15.3%), or gastrointestinal and respiratory symptoms (30.7%). One child developed fulminant hepatic allograft failure secondary to graft involvement by PTLD. Polymorphic PTLD was diagnosed in 6 patients; 7 had the diagnosis of lymphoma. Treatment consisted of stopping immunosuppression as well as starting intravenous gancyclovir and anti-CD20 monoclonal antibody therapy. The mortality rate was 53.8%. The clinical presentation of PTLD varied from fever of unknown origin to fulminant hepatic failure. The other symptoms that may be linked to the diagnosis of PTLD are pancytopenia, tonsil and adenoid hypertrophy, cervical or mediastinal lymph node enlargement, as well as abdominal masses. Despite numerous advances, the optimal treatment approach for PTLD is not completely known and the mortality rate is still high.

Neither Molecular Diversity of the Envelope, Immunosuppression Status, Nor Proviral Load Causes Indeterminate HTLV Western Blot Profiles in Samples From Human T-Cell Lymphotropic Virus Type 2 (HTLV-2)-Infected Individuals

Although human T-cell lymphotropic virus type 2 (HTLV-2) is considered of low pathogenicity, serological diagnosis is important for counseling and monitoring. The confirmatory tests most used are Western blot (WB) and PCR. However, in high-risk populations, about 50% of the indeterminate WB were HTLV-2 positives by PCR. The insensitivity of the WB might be due to the use of recombinant proteins of strains that do not circulate in our country. Another possibility may be a high level of immunosuppression, which could lead to low production of virus, resulting in low stimulation of antibody. We found one mutation, proline to serine in the envelope region in the position 184, presented at least 1/3 of the samples, independent the indeterminate WB profile. In conclusion, we found no correlation of immune state, HTLV-2 proviral load, or env diversity in the K55 region and WB indeterminate results. We believe that the only WB kit available in the market is probably more accurate to detect HTLV-1 antibodies, and some improvement for HTLV-2 detection should be done in the future, especially among high-risk population. J. Med. Virol. 82:837-842,2010. (C) 2010 Wiley-Liss, Inc.

Increased number and function of natural killer cells in human immunodeficiency virus 1-positive subjects co-infected with herpes simplex virus 2

P>Natural killer (NK) cells bridge the interface between innate and adaptive immunity and are implicated in the control of herpes simplex virus 2 (HSV-2) infection. In subjects infected with human immunodeficiency virus 1 (HIV-1), the critical impact of the innate immune response on disease progression has recently come into focus. Higher numbers of NK cells are associated with lower HIV-1 plasma viraemia. Individuals with the compound genotype of killer cell immunoglobulin-like receptor (KIR) 3DS1 and human leucocyte antigen (HLA)-Bw4-80I, or who have alleles of KIR3DL1 that encode proteins highly expressed on the NK cell surface, have a significant delay in disease progression. We studied the effect of HSV-2 co-infection in HIV-1-infected subjects, and show that HSV-2 co-infection results in a pan-lymphocytosis, with elevated absolute numbers of CD4+ and CD8+ T cells, and NK cells. The NK cells in HSV-2 co-infected subjects functioned more efficiently, with an increase in degranulation after in vitro stimulation. The number of NK cells expressing the activating receptors NKp30 and NKp46, and expressing KIR3DL1 or KIR3DS1, was inversely correlated with HIV-1 plasma viral load in subjects mono-infected with HIV-1, but not in subjects co-infected with HSV-2. This suggests that HSV-2 infection mediates changes within the NK cell population that may affect immunity in HIV-1 infection.

Lower numbers of circulating natural killer T (NK T) cells in individuals with human T lymphotropic virus type 1 (HTLV-1) associated neurological disease

Human T lymphotropic virus type 1 (HTLV-1) infects 10-20 million people worldwide. The majority of infected individuals are asymptomatic; however, approximately 3% develop the debilitating neurological disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). There is also currently no cure, vaccine or effective therapy for HTLV-1 infection, and the mechanisms for progression to HAM/TSP remain unclear. NK T cells are an immunoregulatory T cell subset whose frequencies and effector functions are associated critically with immunity against infectious diseases. We hypothesized that NK T cells are associated with HAM/TSP progression. We measured NK T cell frequencies and absolute numbers in individuals with HAM/TSP infection from two cohorts on two continents: Sao Paulo, Brazil and San Francisco, CA, USA, and found significantly lower levels when compared with healthy subjects and/or asymptomatic carriers. Also, the circulating NK T cell compartment in HAM/TSP subjects is comprised of significantly more CD4(+) and fewer CD8(+) cells than healthy controls. These findings suggest that lower numbers of circulating NK T cells and enrichment of the CD4(+) NK T subset are associated with HTLV-1 disease progression.

GB virus type C infection modulates T-cell activation independently of HIV-1 viral load

Background: Many clinical studies have suggested a beneficial effect of GB virus type C (GBV-C) on the course of HIV-1 infection, but the mechanisms involved in such amelioration are not clear. As recent evidence has implicated cellular activation in HIV-1 pathogenesis, we investigated the effect of GBV-C viremia on T-cell activation in early HIV-1 infection. Methods: Forty-eight recently infected HIV-1 patients (23 GBV-C viremic) were evaluated for T-cell counts, expanded immunophenotyping GBV-C RNA detection, and HIV-1 viral load. Nonparametric univariate and multivariate analyses were carried out to identify variables associated with cellular activation, including GBV-C status, HIV-1 viral load, T lymphocyte counts, and CD38 and chemokine (C-C motif) receptor 5 (CCR5) surface expression. Finding: We not only confirmed the positive correlation between HIV-1 viral load and the percentage of T cells positive for CD38(+)CD8(+) but also observed that GBV-C viremic patients had a lower percentage of T cells positive for CD38(+)CD4(+), CD38(+)CD8(+), CCR5(+)CD4(+), and CCR5(+)CD8(+) compared with HIV-1-infected patients who were not GBV-C viremic. In regression models, GBV-C RNA(+) status was associated with a reduction in the CD38 on CD4(+) or CD8(+) T cells and CCR5(+) on CD8(+) T cells, independent of the HIV-1 viral load or CD4(+) and CD8(+) T-cell counts. These results were also supported by the lower expression of CD69 and CD25 in GBV-C viremic patients. Interpretation: The association between GBV-C replication and lower T-cell activation may be a key mechanism involved in the protection conferred by this virus against HIV-1 disease progression to immunodeficiency in HIV-1-infected patients. (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins

Conservation of hepatitis C virus nonstructural protein 3 amino acid sequence in viral isolates during liver transplantation

As a consequence of selective pressure exerted by the immune response during hepatitis C virus (HCV) infection, a high rate of nucleotide mutations in the viral genome is observed which leads to the emergence of viral escape mutants. The aim of this study was to evaluate the evolution of the amino acid (aa) sequence of the HCV nonstructural protein 3 (NS3) in viral isolates after liver transplantation. Six patients with HCV-induced liver disease undergoing liver transplantation (LT) were followed up for sequence analysis. Hepatitis C recurrence was observed in all patients after LT. The rate of synonymous (dS) nucleotide substitutions was much higher than that of nonsynonymous (dN) ones in the NS3 encoding region. The high values of the dS/dN ratios suggest no sustained adaptive evolution selection pressure and, therefore, absence of specific NS3 viral populations. Clinical genotype assignments were supported by phylogenetic analysis. Serial samples from each patient showed lower mean nucleotide genetic distance when compared with samples of the same HCV genotype and subtype. The NS3 samples studied had an N-terminal aa sequence with several differences as compared with reference ones, mainly in genotype 1b-infected patients. After LT, as compared with the sequences before, a few reverted aa substitutions and several established aa substitutions were observed at the N-terminal of NS3. Sites described to be involved in important functions of NS3, notably those of the catalytic triad and zinc binding, remained unaltered in terms of aa sequence. Rare or frequent aa substitutions occurred indiscriminately in different positions. Several cytotoxic T lymphocyte epitopes described for HCV were present in our 1b samples. Nevertheless, the deduced secondary structure of the NS3 protease showed a few alterations in samples from genotype 3a patients, but none were seen in 1b cases. Our data, obtained from patients under important selective pressure during LT, show that the NS3 protease remains well conserved, mainly in HCV 3a patients. It reinforces its potential use as an antigenic candidate for further studies aiming at the development of a protective immune response.

Transcriptional Errors in Human Immunodeficiency Virus Type 1 Generate Targets for T-Cell Responses

We measured T-cell responses to human immunodeficiency virus type 1 (HIV-1) cryptic epitopes encoded by regions of the viral genome not normally translated into viral proteins. T-cell responses to cryptic epitopes and to regions normally spliced out of the HIV-1 viral proteins Rev and Tat were detected in HIV-1-infected subjects.

Comparative Study of the Standard Fluorescent Antibody to Membrane Antigen (FAMA) Assay and a Flow Cytometry-Adapted FAMA Assay To Assess Immunity to Varicella-Zoster Virus

A flow cytometry-adapted fluorescent antibody to membrane antigen (FAMA) assay to detect IgG antibodies against varicella-zoster virus (VZV) was developed and tested in 62 serum samples, showing 90.32% accuracy obtained from a receiver operating characteristic (ROC) curve with a 0.9125 (95% confidence interval [CI], 0.829 to 1.00) area below the curve compared to the result with standard FAMA.