Immunophenotypic analyses of CD34(+) cell subsets in bone marrow from HIV-infected patients during highly- active antiretroviral therapy

A Mother-to-Child Transmission Study in Nigeria: The Impact of Maternal HIV Infection and HAART on Plasma Immunoglobulins, Cytokine Profiles and Infant Outcome

Prevention of mother-to-child transmission (PMTCT) of HIV with highly active antiretroviral therapy (HARRT) allows the HIV⁺ pregnant mothers to have vaginal delivery and breastfeed. Here we investigated the maternal plasma immunoglobulin, cytokine secretion and the outcome of the exposed infants among the HIV⁺ HAART treated pregnant women in Nigeria. In this study, different plasma immunoglobulins and cytokines were measured in the HIV⁺ HAART treated pregnant mothers. Pooled culture supernatants of B and T lymphocytes showed lower levels of IFN-γ, IL-10 and IL-4. There were lower IFN-γ and IL-10 secretions at 1st trimester; however, IL-10 continued to be lower throughout 2nd and 3rd trimesters. TNF-α secretion significantly decreased as pregnancy progressed to term. There were high plasma IgG and low IgM in the HIV⁺ HAART treated pregnant women. Plasma IgG was high during 1st and 3rd trimesters. After one year of follow up, all the exposed children were seronegative for HIV-1 and HIV-2. Vaginal delivery and breastfeeding among HIV⁺ HAART treated mothers have shown to be safe. The use of HAART by the infected mothers and the use of septrin and niverapin by the exposed infants prevented mother to-child transmission of HIV.

Hematopoietic Stem/Progenitor Cells and the Pathogenesis of HIV/AIDS

The interaction between human immunodeficiency virus (HIV) and hematopoietic stem/progenitor cells (HSPCs) has been of great interest. However, it remains unclear whether HSPCs can act as viral reservoirs. Many studies have reported the presence of latently infected HSPCs in the bone marrow of HIV-infected patients, whereas many other investigators have reported negative results. Hence, further evidence is required to elucidate this controversy. The other arm of HSPC investigations of HIV infection involves dynamics analysis in the early and late stages of infection to understand the impact on the pathogenesis of acquired immunodeficiency syndrome. Several recent studies have suggested reduced amounts and/or functional impairment of multipotent, myeloid, and lymphoid progenitors in HIV infection that may contribute to hematological manifestations, including anemia, pancytopenia, and T-cell depletion. In addition, ongoing and future studies on the senescence of HSPCs are expected to further the understanding of HIV pathogenesis. This mini review summarizes reports describing the basic aspects of hematopoiesis in response to HIV infection and offers insights into the association of HIV infection/exposure of the host HSPCs and hematopoietic potential.

HIV-associated lymphoma in the era of combination antiretroviral therapy: shifting the immunological landscape

HIV infection increases the risk of many types of cancer, including lymphoma. Combination antiretroviral therapy (cART) has reduced, but not eliminated, the risk of HIV-associated lymphoma. There has been a substantial shift in the subtypes of lymphoma observed in HIV-infected patients treated with cART. In this review, we will first outline these changes based on epidemiological studies and describe the impact of cART on lymphoma risk and mortality. Then, we will discuss some immunological factors that may contribute to the increased risk of lymphoma persisting after the administration of cART, including immunological non-response to therapy, chronic B-cell activation and dysfunction, T follicular helper cells, natural killer cells and altered lymphopoiesis. A better understanding of the pathophysiologic mechanisms of HIV-associated lymphoma under effective cART will inform future treatment strategies.

The impact of maternal HIV infection on cord blood lymphocyte subsets and cytokine profile in exposed non-infected newborns

Background

Children born to HIV+ mothers are exposed intra-utero to several drugs and cytokines that can modify the developing immune system, and influence the newborn's immune response to infections and vaccines. We analyzed the relation between the distribution of cord blood lymphocyte subsets and cytokine profile in term newborns of HIV+ mothers using HAART during pregnancy and compared them to normal newborns.

Methods

In a prospective, controlled study, 36 mother-child pairs from HIV+ mothers and 15 HIV-uninfected mothers were studied. Hematological features and cytokine profiles of mothers at 35 weeks of pregnancy were examined. Maternal and cord lymphocyte subsets as well as B-cell maturation in cord blood were analyzed by flow cytometry. The non-stimulated, as well as BCG- and PHA-stimulated production of IL2, IL4, IL7, IL10, IL12, IFN-γ and TNF-alpha in mononuclear cell cultures from mothers and infants were quantified using ELISA.

Results

After one year follow-up none of the exposed infants became seropositive for HIV. An increase in B lymphocytes, especially the CD19/CD5+ ones, was observed in cord blood of HIV-exposed newborns. Children of HIV+ hard drug using mothers had also an increase of immature B-cells. Cord blood mononuclear cells of HIV-exposed newborns produced less IL-4 and IL-7 and more IL-10 and IFN-γ in culture than those of uninfected mothers. Cytokine values in supernatants were similar in infants and their mothers except for IFN-γ and TNF-alpha that were higher in HIV+ mothers, especially in drug abusing ones. Cord blood CD19/CD5+ lymphocytes showed a positive correlation with cord IL-7 and IL-10. A higher maternal age and smoking was associated with a decrease of cord blood CD4+ cells.

Conclusions

in uninfected infants born to HIV+ women, several immunological abnormalities were found, related to the residual maternal immune changes induced by the HIV infection and those associated with antiretroviral treatment. Maternal smoking was associated to changes in cord CD3/CD4 lymphocytes and maternal hard drug abuse was associated with more pronounced changes in the cord B cell line.

Immunologic features of HIV-1-infected women on HAART at delivery

BACKGROUND

The conjoint effect of HIV infection and pregnancy on the immune system of women submitted to the prophylactic antiretroviral therapy presently recommended is still poorly understood.

METHODS

We evaluated 44 HIV-infected women (HIV) and 45 HIV-negative women (CT) at parturition and we compared them to 20 healthy nonpregnant women (NP). Immunophenotyping of lymphocytes was done by four-color flow cytometry.

RESULTS

All HIV-infected women received HAART during pregnancy and 56.8% had viral load <50 copies/mL at delivery. CD4+T cells/mm(3) were lower in HIV (447) than CT (593) and NP (738) (P < 0.05). CD8+T cells/mm(3) were higher in HIV (799) than CT (384) and NP (395) (P < 0.05). NK cells/mm(3) were lower in HIV (146) than in CT (253) and NP (198) (P < 0.05). CD38 expression on CD4+T and on CD8+T cells was higher in HIV (CD4:12.1; CD8:14.9) than in CT(CD4:9.2; CD8:10.2) and NP(CD4:8.6; CD8:6.0) (P < 0.05). However, CD56 expression on CD8+T cells (a marker of cytolytic effector function) was lower in HIV(7%) than in CT(12%) and NP(9%) (P < 0.05).

CONCLUSIONS

Even with low levels of viremia, HIV-infected women at delivery showed a different immunologic profile from both healthy non-HIV-infected women in the puerperium and nonpregnant women, with lower CD4+T and higher CD8+T cells, high levels of CD38 expression, but low CD56 expression on CD8+T cells and low NK cell numbers.

Decreased serum lipocalin-2 levels in human immunodeficiency virus-infected patients: increase during highly active anti-retroviral therapy

Although neutrophil gelatinase-associated lipocalin (NGAL) may play a pivotal role in the innate immune response, there are currently no data on NGAL levels in human immunodeficiency virus (HIV)-infected patients. In this study we aimed to examine the regulation of NGAL in HIV infection. The regulation of NGAL in HIV infection was examined by different experimental approaches, including studies in peripheral blood and mononuclear cells (MNC) from bone marrow aspirates before and during highly active anti-retroviral therapy (HAART). We found that: before initiating HAART, HIV-infected patients (n = 37) had significantly decreased serum NGAL levels compared with healthy controls (n = 26); (ii) during HAART, there was a gradual and significant increase in NGAL concentrations reaching levels comparable to those in healthy controls after 12 months; (iii) this increase was seen primarily in virological responders to HAART (HIV RNA level <200 copies/ml after 24 months); (iv) phytohaemagglutinin-stimulated NGAL release in MNC cells from bone marrow aspirates was decreased in untreated HIV-infected patients compared with healthy controls, but increased after 26 weeks on HAART; and (v) there was a significant positive correlation between neutrophil counts and NGAL levels at all time-points during HAART. We have shown decreased NGAL levels in HIV-infected patients, potentially reflecting decreased number and function of neutrophils as well as impaired bone marrow myelopoiesis. These abnormalities were reversed by successful HAART. Our findings underscore further the involvement of neutrophils and innate immunity in HIV-related immunodeficiency.