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A branched DNA method for the quantification of human immunodeficiency virus type 1 (HIV-1) RNA levels (Quantiplex HIV RNA 2.0) was compared with a reverse transcriptase-coupled polymerase chain reaction method (Amplicor HIV-1 Monitor) and a nucleic acid sequence-based assay (Nuclisens HIV-1 QT) in plasma samples from a group of HIV-1 seropositive patients. We found a high correlation between Nuclisens and Quantiplex (r = 0.89; p0.001) and between Amplicor and Quantiplex (r = 0.94; p0.001), a shift of RNA viral load to higher Nuclisens and Amplicor values compared with the Quantiplex results and a significant positive correlation (rS = 0.60; p0.001) between the p24 antigen level and the RNA viral load determined with the Quantiplex assay. We also found higher sensitivities of the Nuclisens and the Amplicor procedures compared with the Quantiplex assay. The total sensivity of the Quantiplex assay in our study was 70% whereas that of the p24 antigen was only 29%.

A case of polyarteritis nodosa identified by the American College of Rheumatology (ACR) 1990 criteria in a 44-year-old HIV-infected man is described. The search for cytomegalovirus, HBV and B19 parvovirus infections was negative. In situ hybridization did not reveal proviral HIV-1 DNA in a skin sample. A zidovudine-associated vasculitis was excluded. Corticosteroid therapy resolved vasculitis manifestations and was well tolerated without opportunistic infections during the 10-month follow-up period. An indirect pathogenetic role of HIV as a possible cause of vascular damage cannot be excluded in our patient.

The production of granulocyte/macrophage-colony stimulating factor (GM-CSF), interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha) were evaluated in the supernatants of short-term cultures of purified CD4+ T-lymphocytes and enriched monocytes obtained from peripheral blood (PB) of 35 HIV-1 seropositive (+) asymptomatic individuals, stages I-II of the Walter Reed (WR) classification, 15 HIV (+) symptomatic patients (WR V-VI) and 40 HIV-1 seronegative normal blood donors. IL-1 beta and TNF-alpha production by either enriched monocytes or isolated CD4+ T-cells, was similar in HIV-1 (+) asymptomatic, symptomatic subjects and normal controls. GM-CSF level in enriched monocyte culture supernatants did not show any significant difference in the three groups of subjects under investigation. On the other hand, GM-CSF production by isolated CD4+ T-lymphocytes was two-fold decreased in HIV-1 (+) asymptomatic subjects and five-fold decreased in HIV-1 (+) symptomatic patients with respect to normal blood donors. The decline in GM-CSF production was clearly correlated with viral isolation from patient's PB light density mononuclear cells (r = -0.920, p less than 0.01). The selective and progressive decline in GM-CSF production by CD4+ T-lymphocytes, starting from early stages of HIV-1 infection, suggest a preferential lesion of a specific subset of CD4+ T-lymphocytes characterized by an intense production of GM-CSF and may contribute to explain the deranged inflammatory and immune responses which characterize the course of HIV-1 infection.

A CD34+ human hematopoietic progenitor cell lines, KG-1, became susceptible to HIV-1 infection in the presence of a concurrent infection by human herpesvirus-6 (HHV-6). We have now analyzed the possible mechanism(s) underlying this phenomenon, in the light of the recent demonstration that at least two members of the chemokine receptor family, CXCR4 (LESTR/fusin) and CCR5 molecules, are the HIV-1-specific co-receptors, necessary, together with the high affinity receptor CD4, for the entry into target cells of HIV-1. Cytofluorimetric analysis demonstrated that in KG-1 cells, after HHV-6 infection, more than 40% of cell population became CD4 positive and only in KG-1 cells expressing the CD4+ phenotype, the exposure to r-gp120 masks a significant amount, not only of CD4, but also of both CXCR4 and CCR5 chemokine receptors. In fact, only when pre-infected by HHV-6, KG-1 cells, after exposure to r-gp120, exhibit a significant reduction in the percentage of CXCR4 or CCR5-positive cells.

In human immunodeficiency virus type-1 (HIV-1) infected individuals, CD34+ hematopoietic stem/progenitor cells are profoundly impaired in their proliferation/differentiation capacities. The bulk of the available experimental evidence seems to indicate that hematopoietic progenitors are not susceptible to HIV-1 infection and their defects seem rather the consequence of direct or indirect negative influences of HIV-1-specific soluble proteins released by productively infected accessory cells. We have now shown that in the presence of a concurrent human herpesvirus-6 infection, two hematopoietic (TF-1 [erythromyeloid] and KG-1 [lymphomyeloid]) progenitor cell lines and human CD34+ hematopoietic progenitors isolated from the bone marrow of normal donors, became susceptible to HIV-1 infection and permissive to HIV-1 replication, although with a limited virus yield. These results suggest a further possible mechanism leading to hematopoietic derangement in HIV-1-infected subjects and may help to clarify the controversial issue of the susceptibility of human hematopoietic progenitors to HIV-1 infection.

Although substantially unsusceptible to HIV-1 infection, human hematopoietic progenitors (CD34+ cells) express significant amounts of gp120-binding CD4 molecules. As some experimental evidence suggests the need for one or more putative cellular accessory factor(s) for efficient CD4-mediate HIV-1 infection, we analyzed the presence and distribution of various adhesion molecules on the surface of two HIV-1-susceptible cell lines (H9 and A3.01) and one HIV-1-unsusceptible, CD4-positive, human hematopoietic progenitor cell line (TF-1). The only difference observed concerned the LFA-1 CD11a protein that has already been shown to be necessary for cell fusion in HIV-1-infected T4 lymphocytes. CD11a was present in a high percentage of HIV-1-susceptible cells and absent in HIV-1-unsusceptible TF-1 cells. A significant increase in HIV-1 replication was obtained in CD11a-enriched H9 cells in comparison with an almost completely CD11a-deprived H9 cell population. The lack of susceptibility to HIV-1 infection in human CD34+ cells may depend on various factors. Nevertheless, the lack of CD11a in a CD34+, CD4+ human hematopoietic progenitor cell line suggests that this molecule may be implicated in the susceptibility to HIV-1 infection.

The true extent of human T-lymphotropic virus type I and II (HTLV-I/II) infection in European countries and its pathogenetic potential are still unknown. To find out more about HTLV-I/II incidence in our area we studied a group of 160 outpatients attending a sexually transmitted disease clinic over a six-month period. All patients were screened for the presence of specific antibody by means of enzyme-linked immunosorbent assay (ELISA) and immunoblotting (IB) analysis, using commercially available reagents. A surprisingly high percentage of patients showed an antibody reactivity to HTLV-I/II antigens by ELISA (9.3%) and IB (6.8%), although none of the samples satisfied the internationally accepted criteria of serological positivity. All subjects, irrespective of doubtful and inconclusive serological results, were further analyzed for the presence of proviral DNA in peripheral blood mononuclear cells by polymerase chain reaction using different pairs of primers and probes. A clear cut positive result for the presence of HTLV-I provirus-related DNA sequences was obtained in peripheral blood mononuclear cells of only one patient, a 26 years old female presenting genital condylomatosis, with no history of blood transfusion and/or intravenous drug abuse. Her serum showed a borderline result at ELISA and an IB reactivity only against p21. These data are open to various possible interpretations and, among others, may represent a hint for the presence of divergent antigenic variants of HTLV-I in the geographical area investigated.

Epidermal Langerhans' cells (LC) from human immunodeficiency virus type-1 (HIV-1)-infected patients harbour HIV-1 proviral DNA and RNA. In the present study, we investigated whether LC from epidermis of normal, HIV-seronegative subjects could be infected in vitro with HIV-1. Epidermal cells (EC) spontaneously detached from epidermal sheet cultures were enriched for LC (10-25% of CD1a+/CD4+ cells), deprived of contaminating T cells and then incubated with HIV-1IIIB. After 24 hr, purified LC and LC-depleted EC fractions were obtained by immunomagnetic separation. Polymerase chain reaction (PCR) analysis showed the presence of HIV-1 proviral DNA (gag) only in purified LC. In addition, LC-enriched EC, purified LC, LC-depleted EC or the non-permissive cell line, TF-1, the latter having being previously challenged with HIV-1IIIB for the same length of time as the EC, were co-cultivated with C8166 cells, and the co-cultures assessed for the presence of HIV DNA by PCR. Co-cultures of C8166 cells with purified LC or LC-enriched EC previously exposed to HIV-1IIIB exhibited a time-dependent increase in HIV proviral DNA. In contrast, PCR analysis of C8166 cells co-cultured with either LC-depleted EC or TF-1 cells gave negative results. Finally, C8166 cells co-cultured with HIV-infected LC formed syncytia, showed membrane budding and released numerous retroviral particles. The results indicate that LC from normal subjects can be infected in vitro with HIV and can transmit infection to myeloid cells. This in vitro model may help in understanding the regulation of HIV infection of LC.

The pathogenetic potential and the true extent of human T leukemia/lymphotropic virus type I (HTLV-I) and type II (HTLV-II) infection are unknown. To find out more about HTLV-I/II seroepidemiology and the risks of iatrogenic transmission, we performed a serological study, screening 4086 healthy blood donors. A surprisingly high percentage of serum reactivity to HTLV-I/II antigens was observed by commercial ELISA (2.08%) and immunoblotting (IB) (0.85%) analysis, although none of the samples satisfied the (IB) criteria for positivity based on detection of gag protein p24 and at least one env gene product, either gp46 or gp61/68. To clarify these inconclusive results, we performed polymerase chain reaction (PCR) analysis for HTLV-I and HTLV-II provirus detection in peripheral blood lymphocytes, obtained from individuals with an apparent pattern of seropositivity. The data obtained by PCR failed to reveal evidence of HTLV-I/II provirus integration in peripheral blood cells, ruling out the possibility of a viral infection in these cases, and pinpointing the limitations of both serological methods used. Our observations suggest that serological assays alone are not a reliable tool for blood donor screening of HTLV-I/II infection and raise the important question of interpreting inconclusive results.

Background and aims: Low-density lipoprotein-cholesterol (LDL-C) is the major determinant of cardiovascular disease (CVD) burden. Being the direct assays time consuming, expensive, not fully standardized and not worldwide available, indirect formulas represent the most used laboratory estimation of LDL-C. In this study we analyzed the accuracy of twelve formulas for LDL-C estimation in an Italian population of 114,774 individuals. Methods: All lipid samples were analyzed using direct homogeneous assay. The population was divided into various subgroups based on triglycerides and directly dosed LDL-C (D-LDL) levels. Twelve formulas (Friedewald, DeLong, Hata, Hattori, Puavillai, Anandaraja, Ahmadi, Chen, Vujovic, de Cordova, Martin, and Sampson) were compared in terms of their mean absolute deviations and the correlation and concordance of their estimated LDL-C with the respective D-LDL values. Results: LCL-C measured by Friedewald formula and direct assay differed by more than 9 mg/dL. For D-LDL>115 mg/dl, we observed a concordance rate of only 55% between Friedewald and the respective D-LDL values. For TG

Background: Therapeutic drug monitoring (TDM) can be a useful tool in the clinical management of anti-hepatitis C virus (anti-HCV) drugs. Methods for the determination of various types of anti-HCV drugs in biological samples are, therefore, needed for clinical laboratories. Objective: In this work, employing the LC–MS/MS approach, we aimed to develop a multiplexed method for identification of the following anti-HCV drugs: Ribavirin (RBV), Boceprevir (BOC), Telaprevir (TVR), Simeprevir (SIM), Daclatasvir (DAC), Sofosbuvir (SOF) and its metabolite GS 331007 (SOFM) in liquid plasma and in dried plasma spots (DPSs). Method: A single-step extractive-deproteinization was employed for both liquid plasma and DPSs. Reverse-phase liquid chromatography coupled with MRM detection was developed for multiplexed drug detection and quantification. Results: Sensitivities (expressed as LOQ) were 10 ( ± 1.2), 10 ( ± 4.9), 10 ( ± 4.4), 10 ( ± 4.4), 10 ( ± 6.4), 10 ( ± 3.4), 10 ( ± 6.4) ng/ml for RBV, SOFM, SOF, DAC, BOC, TVR, and SIM, respectively; accuracy (expressed as BIAS%) was < 10% for all drugs; reproducibility (intra- and inter-day CV%) was < 10% for all drugs; dynamic range was 10–10,000 ng/ml for all drugs. Conclusions: A novel, simple, rapid and robust LC–MS/MS multiplex assay for the TDM of various anti-HCV drugs that are currently in the clinic was successfully developed. Application to DPS samples enabled TDM to be used for outpatients as well.