Persistence of CCR5 usage among primary human immunodeficiency virus isolates of individuals receiving intermittent interleukin-2

OBJECTIVE

To investigate the impact of intermittent interleukin-2 (IL-2) plus combination antiretroviral therapy (cART) on HIV-1 entry co-receptor use.

METHODS

Primary HIV-1 isolates were obtained from 54 HIV-1-positive individuals at baseline and after 12 months using co-cultivation of peripheral blood mononuclear cells (PBMC) with activated PBMC of HIV-negative healthy donors. HIV-1 co-receptor use was determined on U87-CD4 cells.

RESULTS

Fourteen out of the 21 (67%) IL-2-treated individuals harbouring a primary CCR5-dependent (R5) HIV-1 isolate at baseline confirmed an R5 virus isolation after 12 months in contrast to 3 out of 7 (43%) of those receiving cART only. After 12 months, only 1 R5X4 HIV-1 isolate was obtained from 21 cART+IL-2-treated individuals infected with an R5 virus at entry (5%) vs. 2/7 (29%) patients receiving cART alone, as confirmed by a 5-year follow-up on some individuals.

CONCLUSIONS

Intermittent IL-2 administration plus cART may prevent evolution towards CXCR4 usage in individuals infected with R5 HIV-1.

Evaluation of platelet turnover by flow cytometry

The number of circulating newly produced platelets depends on the thrombopoietic capacity of bone marrow as well as platelet removal from the bloodstream. Flow cytometric analysis with thiazole orange (TO), a fluorescent dye that crosses platelet membranes and binds intracellular RNA, has been used to measure circulating reticulated platelets (RPs) with high RNA content as an index of platelet turnover. We first assessed the specificity of TO flow cytometry and then applied this method in the diagnosis of thrombocytopenia caused by impaired platelet production or increased destruction. We also explored the utility of TO flow cytometry to predict thrombocytopoiesis after chemotherapy-induced bone marrow aplasia. Venous blood, anticoagulated with K(2)EDTA, was incubated with 0.6 microg/ml TO plus an anti-GPIIIa monoclonal antibody. The mean percentage of RPs in control subjects (n = 23) was 6.13 +/- 3.09%. RPs were 10.41 +/- 9.02% in patients (n = 10) with hematological malignancies during aplasia induced by chemotherapy and a significant increase in RPs (35.45 +/- 6.11%) was seen in the recovery phase. In 10 patients with idiopathic thrombocytopenic purpura, the percentage of TO positive platelets was 67.81 +/- 18.79 (P < 0.001 vs. controls). In patients with thrombocytopenia associated with hepatic cirrhosis (n = 21; 21.04 +/- 16.21%, P < 0.001 vs. controls) or systemic lupus erythematosus (n = 6, 29.08 +/- 15.57%; P < 0.001 vs. controls) increases in TO-stained platelets were also observed. Measurement of TO positive platelets may be a reliable tool for the laboratory identification of platelet disorders, with a higher sensitivity than measurement of platelet volume. Measurement of RPs may also prove useful to recognize the underlying pathogenetic mechanisms in thrombocytopenia.

Tumor Necrosis Factor-α in Airway Secretions from Cystic Fibrosis Patients Upregulate Endothelial Adhesion Molecules and Induce Airway Epithelial Cell Apoptosis: Implications for Cystic Fibrosis Lung Disease

Airway inflammation plays a crucial role in lung damage in cystic fibrosis (CF) and is characterized by a persistent influx of neutrophils into the airways. We hypothesized that the high levels of inflammatory products that accumulate in the microenvironment of the CF lung contribute to induce the persistent neutrophil recruitment and the airway epithelial damage. Thus, we evaluated the in vitro effect of sputum sol phase (SSP) from CF patients on a) adhesion molecule expression by human microvascular endothelial cells (HMECs) and b) apoptosis of human bronchial epithelial cells (HBECs), both wild-type and CFTR-defective. SSP was obtained from 7 clinically stable adult CF patients and 8 patients with an acute exacerbation. HMECs and HBECs were cultured in the absence or presence of SSP. Cell adhesion molecule expression was assessed by flow cytometry and cell death by the detection of histone-associated DNA fragments, caspase activation, and cytochrome c release. SSP obtained from CF patients, especially at the time of an acute exacerbation, induced a) an upregulation of endothelial adhesion molecules on cultured HMECs that was associated with an increase of neutrophil adhesion to these cells, and was mediated at least in part by TNF-α and IL-1 and b) apoptosis of airway epithelial cells, mainly activated by TNF-α pathway. These results suggest that the high concentrations of inflammatory mediators in CF airways contribute both to the chronic neutrophil influx and the airway damage, and support the crucial role of early anti-inflammatory treatment in the disease.

Isolation and quantitation of HIV in peripheral blood

Quantitation of replication-competent human immunodeficiency virus (HIV) in peripheral blood of infected individuals is critical for investigations of HIV pathogenesis and therapy. In this unit, the basic protocol determines the HIV titer in seropositive blood by measuring the tissue culture infectious dose (TCID) by an end-point dilution method. A second basic protocol utilizes the PHA-stimulated T cell blasts (activated T cells) in co-culture with PBMC as described in the first basic protocol for the short-term growth of HIV in vitro. An Alternate Protocol describes the accumulative method of determining 50% tissue culture infectious dose (TCID(50)) of HIV using the Reed-Muench equation when multiple replicates of a given sample are employed in the assay. A consequence of HIV infection is the depletion of CD4(+) target cells, evidenced by syncytia formation or single-cell death; two support protocols detail the evaluation of these cytopathic effects.

Restoration of anti-tetanus toxoid responses in patients initiating highly active antiretroviral therapy with or without a boost immunization: an INITIO substudy

INITIO is an open-labelled randomized trial evaluating first-line therapeutic strategies for human immunodeficiency virus-1 (HIV-1) infection. In an immunology substudy a tetanus toxoid booster (TTB) immunization was planned for 24 weeks after initiation of highly active antiretroviral therapy (HAART). All patients had received tetanus toxoid immunization in childhood. Generation of proliferative responses to tetanus toxoid was compared in two groups of patients, those receiving a protease inhibitor (PI)-sparing regimen (n = 21) and those receiving a PI-containing (n = 54) regimen. Fifty-two participants received a TTB immunization [PI-sparing (n = 15), PI-containing (n = 37)] and 23 participants did not [PI-sparing (n = 6) or PI-containing (n = 17)]. Cellular responses to tetanus antigen were monitored by lymphoproliferation at time of immunization and every 24 weeks to week 156. Proportions with a positive response (defined as stimulation index > or = 3 and Delta counts per minute > or = 3000) were compared at weeks 96 and 156. All analyses were intent-to-treat. Fifty-two participants had a TTB immunization at median 25 weeks; 23 patients did not. At weeks 96 and 156 there was no evidence of a difference in tetanus-specific responses, between those with or without TTB immunization (P = 0.2, P = 0.4). There was no difference in the proportion with response between those with PI-sparing or PI-containing regimens at both time-points (P = 0.8, P = 0.7). The proliferative response to tetanus toxoid was unaffected by initial HAART regimen. Anti-tetanus responses appear to reconstitute eventually in most patients over 156 weeks when treated successfully with HAART, irrespective of whether or not a TTB immunization has been administered.

Otologic findings in children with gastroesophageal reflux

BACKGROUND

Nearly 90-95% of children with drool have physiologic gastroesophageal reflux (GER) that usually resolves by 12-15 months of age; however, 5-10% of children with drool have pathologic GER. Of these children, most recover clinically by 18 months of age without therapy, yet 10% develop chronic, recurrent gastroesophageal reflux disease (GERD) with sequelae. The respiratory symptoms associated with GER consist mainly of bronchial asthma and laryngospasm, but often include a persistent cough of unknown aetiology, obstructive apnoea, and an obstructive respiratory syndrome confined to the nasopharynx. Gastric acid reflux, enters the adenoids, causes oedema of the tubal orifices, and later leads to relapsing diseases of the middle ear in children.

AIM AND SCOPE

To evaluate the incidence of otologic manifestations in children with GER and the efficacy of treatment, comparing two different groups of children (i.e., treated versus untreated).

SUBJECTS AND METHODS

From January 2005 to November 2006, audiologic screening of newborns and suckling children (0-24 months of age) at risk for auditory illnesses was held at the University Department of Otolaryngology in Catania. Seventy-three children (average age, 13 months) were selected after failing acoustic otoemissions for chronic bilateral catarrhal pathology involving the middle ear (tympanometry type B) and were positive for at least one of the different signs of GER at the time of history-taking. The children were randomised and subdivided into two groups: (1) a group of 40 children (27 females and 13 males; average age, 12 months) who received treatment; and (2) a group of 29 children (16 males and 13 females; average age, 14 months) who did not receive treatment. Four children were lost to follow-up after completing the study. All children enrolled in the study underwent a rhinopharynxlaryngeal fibroscopy with flexible optics, a gastric ultrasound scan after clinical observation, and a multi-channel pH-metry for 18-24h.

RESULTS

Findings obtained by rhinopharynxlaryngeal fibroscopy showed that 82% of cases had diffuse hyperaemia involving the entire rhinopharyngeal mucosa and 13% of the cases had arytenoidal hyperaemia. Resolution and improvement of the reflux occurred in 52.5 and 40% of the cases in the treated group, respectively, versus complete resolution and an improvement in symptoms of 45 and 30% of cases, respectively, in the control group.

CONCLUSIONS

The hypothesis of a correlation between reflux and chronic middle otitis of the serous-mucous type was confirmed in the present study. Adopting a preventive treatment strategy may be useful in reducing the possibility of ear involvement.

Impact of different inhibitor reactivities with commercial factor VIII concentrates on thrombin generation

In order to describe the haemostatic role of a variation in inhibitor reactivity with different factor VIII (FVIII) concentrates, we have compared inhibitor titres against a panel of FVIII concentrates and correlated titre with the capacity to inhibit thrombin generation. Three plasma-derived concentrates were tested in vitro in mixing experiments with inhibitor plasmas from 11 patients with severe haemophilia A: Fanhdi, which contains von Willebrand factor (VWF) with a final ratio of approximately 1:1 (VWF IU per IU FVIII:C); Haemate-P with a ratio of 2.5:1 and Hemofil-M containing only trace amounts of VWF. In addition, the recombinant FVIII concentrate Kogenate Bayer containing no VWF was included. Inhibitor titres and the capacity to generate thrombin were measured. A statistically significant difference in measured titres was found with the highest titres recorded against Hemofil-M. The inhibitor titres needed to inhibit 50% maximum thrombin generation were the lowest for Kogenate Bayer and the highest and similar for Fanhdi and Haemate-P with intermediate titres needed for inhibition of Hemofil-M. In this study, the thrombin generation assay provides additional indications for the role of VWF in the treatment of patients with inhibitors. The VWF-containing concentrates Fanhdi and Haemate-P, added to FVIII-deficient plasma with the presence of inhibitor, generate more thrombin than do the purified concentrates Hemofil-M and Kogenate Bayer.

Tubal ectopic pregnancy: macrophages under the microscope

BACKGROUND

Ectopic pregnancy (EP) is a major reproductive health issue, whose underlying causes remain largely unknown. The unusual macrophage presence in the oviduct affected by EP could indicate macrophage contribution to the pathology.

METHODS

Macrophages have important functions in reproduction that are reviewed in this work. They are needed for tissue remodelling and immune-regulatory roles, and are present both in the ovary and uterus. Numerous cytokines regulate monocytes recruitment, differentiation and function in the reproductive tract, among them leukaemia inhibitory factor (LIF), colony-stimulating factor 1 and transforming growth factor-beta are indispensable and non-redundant for reproductive outcome. Cytokine types and levels are modulated by estrogen, progesterone and seminal plasma, which drive the differentiation of monocytes to immunity cells or to immunosuppressed trophic and scavenging macrophages.

RESULTS

Many risk factors for EP involve an inflammatory reaction that can induce the release of mononuclear phagocytes from the bone marrow and/or favour immunosuppressed trophic differentiation of newly recruited mononuclear phagocytes in the reproductive tract. These observations strengthen the hypothesis that immunosuppressed trophic and scavenging macrophages may have a role in EP onset.

CONCLUSIONS

Macrophages may contribute to the regulation of tubal motility through prostaglandin production and induction of progesterone secretion. Considerations about LIF also suggest that macrophages may have a central role in ectopic receptivity.

Tyr2105Cys mutation in exon 22 of FVIII gene is a risk factor for the development of inhibitors in patients with mild/moderate haemophilia A

We report the case of a patient with mild haemophilia A, due to a Tyr2105Cys mutation in exon 22 of the C1 domain, who developed a high-titre factor VIII inhibitor (maximum titre 1600 BU) with recurrent severe haemorrhages and fatal intracranial bleeding. Based on published data, it appears that although this mutation occurs rarely in patients with mild or moderate haemophilia A, it is frequently associated with the development of high-titre inhibitors.

Hemodynamic monitoring in ICU

Oxygen supply to all tissues is possible only in a condition of adequate blood circulation. Oxygen demand is the driving force that is responsive of hemodynamic adjustment. The human body acts on four modulators (intravascular volume, inotropy, vasoactivity, chrono-tropy) in order to adjust the hemodynamic state. Hemodynamic monitoring consists of techniques able to assess the hemodynamic status and to understand the mechanism of patient decompensation; its goal is to maintain adequate tissue perfusion through appropriate therapeutic interventions. An early diagnosis of hemodynamic alteration is crucial for an early treatment; several reports have explored the effectiveness of hemodynamic manipulations and results are conflicting: too many variables can, in fact, modify the results: timing and lenght of the treatment, drugs used, etc. However, at least, in some specific settings, as sepsis, early intervention has a positive impact on mortality. In this presentation it will be briefly analyzed the most common parameters used in the ICU. Arterial pressure, central venous pressure, pulmonary artery catheter derived parameters, SvO2 and their relation with organ perfusion are considered and positive and negative aspects of this type of monitoring is reviewed. Starting from these considerations we would like to underline the importance of understanding the physiological basis of monitoring and the correct interpretation of data in order to have improvement on patient outcome.

[Pharmacotherapy of sepsis]

Despite an increasingly understanding of the pathogenetic mechanisms of sepsis, its mortality remains extremely high, caused mainly by hemodynamic impairment-related alterations frequently present in severe sepsis. Currently, treatment of sepsis is based on hemodynamic support, antibiotic therapy, surgical excision of infectious foci and immunomodulatory therapy. In fact, a massive host inflammatory infection response has recently emerged to substantially contribute to the development of septic shock and multiple organ dysfunction. Many clinical trials on various pharmacological agents have been conducted: glucocorticoids, nonsteroidal anti-inflammatory drugs (NSAIDs), antithrombin III (AT III), anti-endotoxin monoclonal antibodies, nitric oxide inhibitors, interleukin-1 receptor antagonist, anti-tumor necrosis factor (TNF) antibodies. Apart from some likely favourable findings connected to low doses of glucocorticoids, most studies yielded disappointing results. Nevertheless, the use of recombinant human activated protein C (drotrecogin-alpha) has recently proven to have a mortality reduction effect particularly in patients with severe sepsis and dysfunction of at least two organs. Furthermore, the early treatment of hemodynamic instability with volume expanders and vasopressors (early goal-directed therapy), and a strict glycemic control represent important measures in order to significantly reduce mortality from severe sepsis and septic shock, and are fundamental guidelines recommended by most scientific societies (Surviving Sepsis Campaign).