CD44 involvement in autoimmune inflammations: the lesson to be learned from CD44-targeting by antibody or from knockout mice

CD44 is a multistructural and multifunctional glycoprotein, the diversity of which is generated by alternative splicing. In this communication we review some aspects related to CD44 structure and function in experimental autoimmune inflammation, focusing on research performed in our own laboratory. We have found that CD44 targeting by antibody, passively injected into DBA/1 mice with collagen-induced arthritis (CIA) and NOD mice with type I diabetes or actively generated by CD44 cDNA vaccination of SJL/j mice with autoimmune encephalomyelitis, markedly reduced the pathological manifestations of these diseases by attenuating cell migration of the inflammatory cells and/or by their apoptotic killing. However, genetic deletion of CD44 by knockout technology enhanced the development of CIA because of molecular redundancy mediated by RHAMM (a receptor of hyaluronan-mediated motility). The mechanisms that stand behind these findings are discussed.

The effect of high-dose thiotepa, alone or in combination with other chemotherapeutic agents, on a murine B-cell leukemia model simulating autologous stem cell transplantation

The use of thiotepa (TH) is increasing, especially in stem cell transplantation, mainly due to its safety and blood-brain barrier penetration. We evaluated the use of TH in a murine model simulating autologous stem cell transplantation, with or without additional agents. Between 1 and 11 days following inoculation of BALB/c mice with 10(5)-10(8) B-cell leukemia (BCL1) cells (simulating pre-transplant leukemia loads), each group received an 'induction-like' irradiation and/or cytotoxic regimen. Animals were either followed without treatment, or an adoptive transfer (AT) was performed to untreated BALB/c mice. Administered alone without AT, high-dose TH did not change the time to appearance of leukemia. Nevertheless, in the AT experiments, TH as a single agent showed better antileukemic activity than busulfan (BU). Cyclophosphamide (CY)-containing regimens were the most effective, and the TH-CY combination was as effective as the commonly used BU-CY combination, and more effective than the BU-TH combination. Moreover, a synergistic effect was seen in the TH-CY combination (none of the animals developed leukemia, whereas 4/10 animals in the CY-TBI group developed leukemia (P=0.029)). In conclusion, although TH produced only a moderate effect against BCL1 leukemia when used alone, its combination with CY is promising and should be tested further in allogeneic murine models and clinical studies.

Interleukin-7 induced facilitation of immunological reconstitution of sublethally irradiated mice following treatment with alloreactive spleen cells in a murine model of B-cell leukemia/lymphoma (BCL1)

Interleukin-7 (IL-7) plays a key role in maturation and function of both T and B cells. We investigate the potential use of recombinant human IL-7 for facilitation of graft-versus-leukemia (GVL) effects mediated by T cells following transplantation in a murine model. Administration of IL-7 in vivo to allogeneic-transplanted mice improved disease-free survival: 67% of mice treated with IL-7 remained alive and disease free for more than 60 days, in comparison to 17% of the controls (P<0.05). Similar results were obtained when C57BL/6 spleen cells sensitized against irradiated B-cell leukemia (BCL(1)) cells in the presence of IL-7 were transplanted to F(1) mice, followed by IL-7 treatment in vivo. Of the BALB/c mice that received spleen cells from F(1) mice treated with IL-7 following transplantation of C57BL/6 spleen cells sensitized with irradiated BCL(1) in the presence of IL-7, only 29% developed leukemia, as compared to 79% in the control group (P<0.05). Mice treated with IL-7 showed increased splenic and thymic cellularity and improved T cell-dependent proliferative responses compared to the controls (P<0.05). IL-7 may provide a novel tool to enhance immune reconstitution following transplantation of mismatched stem cells and for enhancement of GVL effects mediated by alloreactive lymphocytes.

The oxidative status of blood cells in a murine model of graft-versus-host disease

We studied the oxidative status of red and white blood cells during the development of graft vs host disease (GVHD) as well as the effects of treatment with antioxidants, both in vitro and in vivo. (BALB/c X C57BL/6) F1 mice were conditioned by total body radiation and, 1 day later, transplanted with semi-allogeneic C57BL/6 spleen cells. GVHD was followed by its clinical manifestations. Oxidative stress in red blood cells (RBC), neutrophils, and lymphocytes was assessed by measuring generation of reactive oxygen species and the content of reduced glutathione by flow cytometry after gating of the specific populations. Oxidative stress was noticed 3 weeks after transplantation. It was higher in mice receiving allogeneic spleen cells as compared with mice transplanted with syngeneic cells, suggesting that it was associated with GVHD. The results also demonstrated that treatment with the antioxidants N-acetylcysteine and a derivative of vitamin E (tocopherol succinate, propofol), both in vitro and in vivo, reduced the oxidative stress. The results indicate that various blood cells, including RBC, neutrophils, and lymphocytes, are under oxidative stress and that treatment with antioxidants reduced the stress and, thus, may be useful in ameliorating the severe consequences of GVHD.

Cannabidiol arrests onset of autoimmune diabetes in NOD mice

We have previously reported that cannabidiol (CBD) lowers the incidence of diabetes in young non-obese diabetes-prone (NOD) female mice. In the present study we show that administration of CBD to 11-14 week old female NOD mice, which are either in a latent diabetes stage or with initial symptoms of diabetes, ameliorates the manifestations of the disease. Diabetes was diagnosed in only 32% of the mice in the CBD-treated group, compared to 86% and 100% in the emulsifier-treated and untreated groups, respectively. In addition, the level of the proinflammatory cytokine IL-12 produced by splenocytes was significantly reduced, whereas the level of the anti-inflammatory IL-10 was significantly elevated following CBD-treatment. Histological examination of the pancreata of CBD-treated mice revealed more intact islets than in the controls. Our data strengthen our previous assumption that CBD, known to be safe in man, can possibly be used as a therapeutic agent for treatment of type 1 diabetes.

N-acetylcysteine mildly inhibits the graft-vs.-leukemia effect but not the lymphokine activated cells (LAK) activity

N-acetylcysteine (NAC) is a known antioxidant and induces modulation of glutathione cellular content effects. It has been suggested that in the context of stem cell transplantation (SCT), NAC can prevent and treat graft-vs.-host disease, veno-occlusive disease and idiopathic pneumonia syndrome. We investigated the possible effect of NAC on graft-vs.-leukemia effect (GVL) and lymphokine activated cells (LAK) activity in murine models. After 10 days of NAC treatment, the cytotoxic activity of the LAK cells did not significantly differ from LAK activity generated from spleen cells obtained from untreated controls. However, NAC mildly suppressed GVL (appearance of leukemia in 8/36 animals treated with NAC as compared to 0/20 in the SCT control group, p=0.023). In spite of this mild suppression of GVL, no negative effect on achievement of donor chimerism was seen. We conclude that NAC usage in SCT may be relatively safe with regard to the GVL effect, yet further clinical studies are warranted.

Cannabidiol lowers incidence of diabetes in non-obese diabetic mice

Cannabidinoids are components of the Cannabis sativa (marijuana) plant that have been shown capable of suppressing inflammation and various aspects of cell-mediated immunity. Cannabidiol (CBD), a non-psychoactive cannabidinoid has been previously shown by us to suppress cell-mediated autoimmune joint destruction in an animal model of rheumatoid arthritis. We now report that CBD treatment significantly reduces the incidence of diabetes in NOD mice from an incidence of 86% in non-treated control mice to an incidence of 30% in CBD-treated mice. CBD treatment also resulted in the significant reduction of plasma levels of the pro-inflammatory cytokines, IFN-gamma and TNF-alpha. Th1-associated cytokine production of in vitro activated T-cells and peritoneal macrophages was also significantly reduced in CBD-treated mice, whereas production of the Th2-associated cytokines, IL-4 and IL-10, was increased when compared to untreated control mice. Histological examination of the pancreatic islets of CBD-treated mice revealed significantly reduced insulitis. Our results indicate that CBD can inhibit and delay destructive insulitis and inflammatory Th1-associated cytokine production in NOD mice resulting in a decreased incidence of diabetes possibly through an immunomodulatory mechanism shifting the immune response from Th1 to Th2 dominance.

Post transplant persistence of host cells augments the intensity of acute graft-versus-host disease and level of donor chimerism, an explanation for graft-versus-host disease and rapid displacement of host cells seen following non-myeloablative stem cell transplantation?

Although the use of non-myeloablative stem cell transplantation (NST) reduces the severity of graft-versus-host disease (GVHD), GVHD remains a major complication following allogeneic transplantation. Since following NST in comparison with myeloablative conditioning, higher proportions of host immunohematopoietic cells may persist while donor-derived alloreactive lymphocytes are being infused, thus possibly serving as host antigen presentation for continuous stimulation of donor T cells, we speculated that GVHD may be similarly amplified by conditioning followed by intentional administration of host cells. This hypothesis was tested in a preclinical animal model. Increased incidence of GVHD, higher mortality and increased levels of chimerism were observed in recipients reconstituted with host cells, particularly with non-irradiated spleen cells. Graft-versus-leukemia effect was not impaired by post transplant cell administration. These results suggest that GVHD may be amplified by recipient cell infusion using either irradiated or viable stimulatory host cells, thus possibly explaining in part higher than anticipated incidence of GVHD and rapid displacement of host cells and conversion to 100% donor type cells following NST. Administration of irradiated host antigen-presenting cells post transplantation may thus represent a potential approach for amplification of the alloreactive capacity of donor lymphocytes following stem cell transplantation.

Improved survival following induction of GVHD following lipopolysaccharide immunization

OBJECTIVE

Graft-vs-host disease (GVHD) is still the primary limitation to the wider application of allogeneic bone marrow transplantation (BMT). On the one hand, it predisposes transplant recipients to risk of bacterial, fungal, and viral infections, on the other, lipopolysaccharide (LPS), an endotoxin found in the cell walls of gram-negative bacteria, has been shown to play a significant role in the development and severity of GVHD following allogeneic myeloablative BMT. Our study focused on immunization of recipient and donor mice with endotoxin prior to transplantation, in an attempt to reduce mortality caused by gram-negative bacterial infections posttransplantation.

MATERIALS AND METHODS

In one experiment, recipient mice were immunized with LPS prior to BMT, whereas in another experiment, donor mice were immunized prior to BMT. The mice were evaluated for development of GVHD and for survival.

RESULTS

Our results showed that injection of low-dose LPS to mice prior to induction of GVHD with allogeneic spleen cells saved more than 40% of the recipients, whereas all mice in the untreated control group died. The survival of recipients of spleen cells from immunized donors rose to 54% and clinical signs of GVHD were attenuated as compared to control mice inoculated with spleen cells obtained from unimmunized donors.

CONCLUSION

This immunization protocol suggests that immunization of the donor or the recipient against LPS prior to transplantation may be protective against gram-negative bacteria.

IFN-gamma acts on T cells to induce NK cell mobilization and accumulation in target organs

The mechanism(s) that regulates NK cell mobilization and the significance of this process to NK cell activity are unknown. After Con A-induced hepatitis, NK cells are mobilized from the spleen and bone marrow into the periphery in an IFN-gamma-dependent fashion. Intraperitoneal administration of IFN-gamma stimulates the mobilization of NK cells into the circulation, but not their cell death or proliferation. Increased number of circulating NK cells was coupled with their accumulation in the peritoneum, liver, and tumor-bearing lung tissue. Furthermore, increased number of NK cells in the lung reduced metastasis of Lewis lung carcinoma cells (3LL cell line) resulting in significantly extended NK-dependent survival. Mobilization of NK cells was specific and required the presence of T cells. Moreover, mobilization and migration of spleen NK cells in response to IFN-gamma treatment is dependent on the chemokine receptor CXCR3. Mechanistic insights regarding the role of IFN-gamma in the regulation of NK cell mobilization and their accumulation at sites of tumor metastasis may lead to the development of novel immunotherapy for cancer.

Effect of fluvastatin on apolipoprotein-defined lipoprotein subclasses in patients with chronic renal insufficiency

According to the concept of apolipoprotein (apo)-defined lipoproteins, apoA-I-containing lipoproteins consist of two subclasses referred to as lipoprotein A-I (LpA-I) and lipoprotein A-I:A-II (LpA-I:A-II), and apoB-containing lipoproteins of five subclasses, namely lipoprotein B (LpB), lipoprotein B:C (LpB:C), lipoprotein B:E (LpB:E), lipoprotein B:C:E (LpB:C:E), and lipoprotein A-II:B:C:D:E (LpA-II:B:C:D:E). The purpose of this study was to determine the levels of apoA-I- and apoB-containing lipoprotein subclasses before and after fluvastatin treatment of patients with chronic renal insufficiency. ApoA-I- and apoB-containing lipoprotein subclasses were measured in 15 patients with chronic renal failure and 15 asymptomatic subjects. The effect of fluvastatin on lipoprotein subclasses was determined in a randomized, double-blind, placebo-controlled, two-way, treatment period crossover study. Patients were administered fluvastatin 40 mg/day or placebo during 8 weeks in a randomized order. Patients were characterized by significantly higher levels of LpB (P < 0.001), LpB:C (P < 0.001), and LpB:E (P < 0.05), and slightly higher levels of LpB:C:E and LpA-II:B:C:D:E than controls. The levels of LpA-I:A-II were significantly lower (P < 0.01) in patients than controls. Fluvastatin treatment reduced all apoB-containing subclasses, but only the reduced level of LpB subclass was statistically significant (P < 0.02). The levels of LpA-I and LpA-I:A-II were not affected. Fluvastatin treatment reduced and normalized LpB and LpB:E subclasses. Although slightly reduced, the levels of markedly atherogenic LpB:C subclass were not normalized. The potential role of LpB:C on the progression of coronary artery disease in chronic renal insufficiency remains to be determined in future studies.

Induction of Early Post-Transplant Graft-versus-Leukemia Effects Using Intentionally Mismatched Donor Lymphocytes and Elimination of Alloantigen-Primed Donor Lymphocytes for Prevention of Graft-versus-Host Disease

Graft-versus-leukemia (GVL) effects can be induced in tolerant mixed chimeras prepared with nonmyeloablative conditioning. GVL effects can be amplified by post-grafting donor lymphocyte infusion (DLI). Unfortunately, DLI is frequently associated with graft-versus-host disease (GVHD). We investigated the feasibility of induction of potent GVL effects by DLI using intentionally mismatched lymphocytes followed by elimination of alloreactive donor T cells by cyclophosphamide for prevention of lethal GVHD following induction of very short yet most potent GVL effects. Mice inoculated with B-cell leukemia (BCL1) and mismatched donor lymphocytes were treated 2 weeks later with low-dose or high-dose cyclophosphamide. All mice receiving cyclophosphamide 2 weeks after DLI survived GVHD, and no residual disease was detected by PCR; all control mice receiving DLI alone died of GVHD. Analysis of host (female) and donor (male) DNA showed that cyclophosphamide treatment eradicated most alloreactive donor cells, yet mixed chimerism was converted to full donor chimerism following transient self-limited GVHD. Our working hypothesis suggests that short-term yet effective and safe adoptive immunotherapy of leukemia may be accomplished early post-transplantation using alloreactive donor lymphocytes, with prevention of GVHD by elimination of GVL effector cells.

The effect of pegylated antisense acetylcholinesterase on hematopoiesis

To determine whether the efficacy of entry and action of antisense oligonucleotides (AS-ODN) on hematopoietic stem cells in vitro could be improved by the addition of polyethylene glycol (PEG), a molecule of PEG was bound to AS- or sense-acetylcholinesterase (AS-ACHE or S-ACHE). The introduction of 0.1-0.5 microM PEG-AS-ACHE or 0.5 microM AS-ACHE into methylcellulose bone marrow (BM) cultures produced a doubling in number of colony-forming unit-granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM) and a 5-fold increase in cell number of the PEG-ODN. Further increase in concentration of the PEG-ODN reduced colony numbers. PEG-AS-ACHE induced higher colony numbers and greatly increased megakaryocyte (MK) formation when compared with PEG and AS-ACHE added separately to the culture. In addition, differentials of the CFU-GEMMs indicated there was a direct relationship between MK number and PEG-AS-ACHE concentration. Under these culture conditions, 5 microM PEG alone gave control values of CFU-GEMM. On addition of FITC-PEG-AS-ACHE to the cell cultures, using confocal microscopy, the nuclei of both early and mature MKs were labeled specifically, whereas all other cellular nuclei were negative to the stain. The use of PEG-AS-ODN, affording specific delivery of AS-ODN to target cells, increased cell proliferation, and enhanced ODN uptake, may be of potential importance in stem cell expansion for BM transplantation and gene therapy.

Impact of Newly Available Drugs on Clinical Progression in Patients with Virological Failure after Exposure to Three Classes of Antiretrovirals

Objective

To study the prognosis of HIV-infected patients with virological failure after exposure to three classes of antiretroviral drugs (ARVs).

Design

Cohort study. Setting: French Hospital Database on HIV.

Patients

Patients previously exposed to at least two nucleoside reverse transcriptase inhibitors (NRTIs), two protease inhibitors and one non-NRTI, with viral load (VL) values of >5000 copies/ml after the exposure criteria were met and a new treatment initiated between 1998 and 2001 with VL >5000 copies/ml.

Main outcome measures

Risk of new AIDS-defining-events (ADEs) or death from first introduction of a drug never used before occurring between 1998 and 2001 defined as baseline.

Results

The main baseline characteristics of the 1092 patients were: previous ADE in 49% of cases, median CD4 cell count 181 μl, median VL 4.9 log10 copies/ml, median duration of ARV therapy 5.0 years and previous exposure to a median of nine ARVs. The crude progression rates were 20.1/100 patient-years among patients included in 1998, 15.1 in 1999, 11.1 in 2000 and 8.6 in 2001. After adjustment for baseline characteristics, the calendar year of inclusion was associated with the risk of clinical progression ( P<0.001). When the types of newly available drugs used at baseline or during follow-up were introduced into the model, year of inclusion was no longer associated with the risk of clinical progression ( P=0.42), while exposure to amprenavir/r, lopinavir/r, abacavir or tenofovir was associated with a lower risk.

Conclusions

The clinical prognosis of heavily pretreated patients experiencing virological failure improved between 1998 and 2001, mainly thanks to the use of newly available drugs with more favourable resistance profiles.

Mycophenolate mofetil does not suppress the graft-versus-leukemia effect or the activity of lymphokine-activated killer (LAK) cells in a murine model

BACKGROUND

Graft-versus-leukemia (GVL) effect is an essential component in the course of allogeneic stem cell transplantation (SCT). However, both prevention and treatment of established graft-versus-host disease (GVHD), including with drugs such as cyclosporine, can suppress GVL effects. Mycophenolate mofetil (MMF) is becoming a standard of care in SCT recipients for better prevention of GVHD as well as for promoting stem cell engraftment.

AIMS

To evaluate the effect of MMF, an immunosuppressive drug increasingly used for prevention of GVHD, on disease recurrence following SCT in a preclinical animal model. Since GVL effects may be also induced by alloreactive natural killer (NK) cells, the goal was to investigate the effects of MMF on the activity of lymphokine-activated killer (LAK) cells.

METHODS

MMF was administered by daily intraperitoneal injection starting at day 1 post-SCT. Cytotoxic LAK activity was measured by 5-h 35S-release assay, and GVL was tested by the appearance of BCL1 leukemia in a semi-mismatched (C57BL/6 donors to [BALB/c x C57BL/6] F1 recipients) murine model.

RESULTS

A dosage regimen of 28-200 mg/kg per day MMF had no negative effect on either cytotoxic LAK activity or GVL (as measured by finding of leukemic cells in recipient spleen by PCR or the appearance of clinical leukemia with adoptive transfer).

CONCLUSIONS

These results suggest that MMF does not impair GVL effects or reduce LAK cell activity in mice.

Murine B-cell leukemia lymphoma (BCL1) cells as a target for NK cell-mediated immunotherapy

Natural killer (NK) cells are important for their ability to recognize and lyse tumor cells and virus infected cells. NK cells express triggering receptors that are specific for non-MHC ligands. This article describes the 35S release cytotoxic assay, which measures the ability of NK cells derived from spleen cells taken from polyIC-treated mice to lyse B-cell leukemia (BCL1) cells. BCL1 cells express ligands for NKp46 on the cell surface membrane and they are sensitive to allogeneic but not syngeneic IL-2 activated natural killer cells.

Microalbuminuria and risk factors in type 1 and type 2 diabetic patients

A prospective study of normoalbuminuric diabetic patients was performed between 1997 and 2002 on 4097 type 1 and 6513 type 2 diabetic patients from the Swedish National Diabetes Register (NDR); mean study period, 4.6 years. The strongest independent baseline risk factors for the development of microalbuminuria (20-200 microg/min) were elevated HbA(1c) and diabetes duration in both types 1 and 2 diabetic patients. Other risk factors were high BMI, elevated systolic and diastolic BP in type 2 patients, and antihypertensive therapy in type 1 patients. A subsequent larger cross-sectional study in 2002 showed that established microalbuminuria was independently associated with HbA(1c), diabetes duration, systolic BP, BMI, smoking and triglycerides in types 1 and 2 diabetic patients, and also with HDL-cholesterol in type 2 patients. Relatively few types 1 and 2 patients with microalbuminuria achieved treatment targets of HbA(1c) < 6.5% (21-48%), BP < 130/85 mmHg (33-13%), cholesterol < 5 mmol/l (48-46%), triglycerides < 1.7 mmol/l (83-48%) and BMI < 25 kg/m(2) (50-18%), respectively. In conclusion, high HbA(1c), BP and BMI were independent risk factors for the development of microalbuminuria in types 1 and 2 diabetic patients. These risk factors as well as triglycerides, HDL-cholesterol and smoking were independently associated with established microalbuminuria. Treatment targets were achieved by a relatively few patients with microalbuminuria.

Effect of Linomide on adhesion molecules, TNF-α, nitrogen oxide, and cell adhesion

Linomide (quinoline-3-carboxamide) is an immunomodulator with anti-inflammatory effects in rodents with autoimmune diseases. Its mode of action still remains to be elucidated. We hypothesized that an investigation of T cell interactions with the extracellular matrix (ECM), composed of glycoproteins such as fibronectin (FN) and laminin (LN), might provide better understanding of their in vivo mode of action in extravascular inflammatory sites. We examined the effect of Linomide on T cell adhesion to intact ECM, and separately to LN, and FN, and on the release and production of tumor necrosis factor (TNFalpha) and nitrogen oxide (NO) in relation to adhesive molecules in non-obese diabetic (NOD) female spleen cells, focusing on intracellular adhesion molecule-1 (ICAM-1) and CD44. NOD female mice that developed spontaneous autoimmune insulitis, which destroys pancreatic islets and subsequently leads to insulin-deficient diabetes mellitus, were studied. Linomide, given in the drinking water or added to tissue cultures in vitro, inhibited the beta1 integrin-mediated adhesion of T cells to ECM, FN and LN, as well as the production and release of TNFalpha and NO, which play a major role in the induction and propagation of T cell-mediated insulitis. In addition, exposure of T cells to Linomide resulted in increased expression of CD44 and ICAM-1 molecules on spleen cells of Linomide-treated mice; such an increase in adhesion molecule expression may lead to more effective arrest of T cell migration in vivo. The regulation of T-cell adhesion, adhesion receptor expression, and inhibition of TNFalpha and NO secretion by Linomide may explain its beneficial role and provide a new tool for suppressing self-reactive T cell-dependent autoimmune diseases.

Immunotherapy of murine leukemia following non-myeloablative conditioning with naïve or G-CSF mobilized blood or bone marrow stem cells

Allogeneic stem cell transplantation (SCT) is the treatment of choice for a large number of hematologic malignancies. Its major advantage over conventional chemotherapy lies in the graft-versus-leukemia (GVL) effects mediated by allo- or tumor-reactive donor lymphocytes given in the course of SCT or post transplantation as donor lymphocyte infusions (DLI). The benefits of cell-mediated immunotherapy over myeloablative radiochemotherapy have also made it possible to reduce the intensity of conditioning regimens. Mobilized peripheral blood has proved preferable to bone marrow (BM) as a source of stem cells for transplantation, since it provides a larger number of stem cells on the one hand and immunologically competent lymphocytes on the other. The use of granulocyte colony stimulating factor (G-CSF), which is necessary to mobilize and increase the number of stem cells, may down-regulate the GVL effect by suppression of donor effector T lymphocytes by inducing Th1-->Th2 cytokine switch. It has previously been shown that GVL effects may be amplified by both in vivo and in vitro activation of donor lymphocytes with human recombinant interleukin-2 (rIL-2). Our studies using a leukemic murine model prepared for transplantation with low intensity conditioning prior to infusion of G-CSF-mobilized peripheral blood stem cells (PBSC) have demonstrated that mobilization of blood cells with G-CSF and in vivo treatment with rIL-2 following low-intensity conditioning enhances the GVL effects and prolongs survival of recipients inoculated with BCL1. Activation of donor lymphocytes with rIL-2 may thus be useful for amplifying GVL effects following mobilization with G-CSF.

Nonmyeloablative stem cell transplantation: reduced-intensity conditioning for cancer immunotherapy—from bench to patient bedside

Despite major progress in treating hematologic malignancies and, to a lesser extent, metastatic solid tumors, much work remains ahead. With the anticancer potential of immunotherapy not yet fully exploited, patients with leukemia, malignant lymphoma, and other hematologic malignancies for which high-dose chemoradiotherapy is frequently recommended in conjunction with stem cell transplantation (SCT) can now benefit from the advantages of immunotherapy mediated by cytokines or alloreactive donor lymphocytes, while minimizing procedure-related toxicity and mortality. The feasibility of applying allogeneic cell-mediated immunotherapy in conjunction with allogeneic SCT following reduced-intensity conditioning, with minimal toxicity and no serious transplant-related complications, makes it possible to undertake such procedures on an outpatient basis as well as to offer an option for cure to elderly individuals and patients with less than optimal performance status. Being well tolerated, reduced-intensity transplants also offer a chance for cure to patients with otherwise resistant leukemia and malignant lymphoma who have relapsed after autologous SCT. Thus, the traditional obstacle of very high transplant-related toxicity and mortality due to multiorgan failure from cumulative toxicity of multiple anticancer agents and radiation therapy is overcome. Although immunotherapy mediated by allogeneic lymphocytes can be most effective, the immune potential of donor lymphocytes should be maximized by nonspecific or specific activation in vitro or in vivo, or both, for more effective eradication of resistant tumor cells, including in patients with bulky disease. More important is the challenge to target donor lymphocytes to the tumor and minimize their capacity to induce responses against normal host tissues, which frequently results in severe acute and chronic graft-versus-host disease (GVHD). Alternatively, donor lymphocytes should be eliminated as soon as tumor eradication is completed, or as soon as severe GVHD becomes prohibitive. Based on available experience, clinical application of innovative therapy, especially at the stage of minimal residual disease (MRD), may open new horizons for the treatment of malignancies considered until recently to be incurable. The feasibility of controlling cancer by targeted chemotherapy, best illustrated by the phenomenal activity of imatinib in patients with chronic myelogenous leukemia and, more recently, in gastrointestinal stromal tumors (including in patients fully resistant to all known anticancer agents) suggests that in the future, tumor-specific chemotherapy may represent the ultimate goal for achieving a stage of MRD with minimal multiorgan toxicity. Together, the combination of immunotherapy and targeted chemotherapy may provide the most logical approach for making real progress in controlling resistant hematologic malignancies and metastatic solid tumors.

HIV-related knowledge and adherence to HAART

Near perfect adherence is considered essential for patients on HAART, yet adherence to medical recommendations is rarely so high. Supportive services and reminder tools may help individuals to become adherent, yet it is difficult to determine who may need such interventions. In this study, based on data from the NYSDOH/AIDS Institute Treatment Adherence Demonstration Program, we look at the association between HIV-related knowledge and adherence, hypothesizing that a better understanding of HIV and its treatment is associated with better adherence. In analyses based on 997 participants, knowledge, as measured by five true/false questions, was significantly associated with self-reported adherence. In multivariate analysis, compared to persons with four or five items answered correctly, persons with fewer correct answers were more likely to report missed doses (OR = 1.72 for 2-3 correct, p < 0.01; OR = 2.92 for 0-1 correct, p < 0.05). Our data suggest that providers should include questions focused on knowledge of HIV in their assessments of medication readiness and need for adherence support. Similarly, providers should be diligent with respect to patient education, ensuring that each patient has the information needed to support reasoned decision making and adequate adherence.

Treatment with halofuginone results in marked growth inhibition of a von Hippel-Lindau pheochromocytoma in vivo

Halofuginone has recently been shown to inhibit tumor progression of various types of cancers. The antitumoral effect was associated with decreased tumor angiogenesis rather than a direct cytostatic effect on the tumor cells. The antiangiogenic action of the drug could be related to its inhibition of collagen type I synthesis, inhibition of matrix metalloproteinases (MMPs), or via both mechanisms because both collagen synthesis and MMP activity have been shown to be involved in angiogenesis. Vascular endothelial growth factor (VEGF), in addition to its effect on endothelial cell proliferation, has been shown to be a potent inducer of MMP expression. Because von Hippel-Lindau (VHL)-associated tumors express high levels of VEGF, it was of interest to ascertain the potential usefulness of halofuginone for treatment of these tumors. Pheochromocytoma tissue fragments obtained at surgery from a VHL type 2a patient were propagated s.c. in male BALB/c nu/nu (nude) mice. For experiments, 2-3-mm tumor fragments were transplanted secondarily s.c. to nude mice. Two treatment groups received halofuginone in standard lab chow at 3 and 5 ppm; control animals received regular chow. All groups were followed for 6 weeks after transplantation. A marked and significant diminution of tumor size and weight was observed in the drug-treated animals (>90% reduction of mean tumor volume for both the 3 and 5 ppm groups). In vivo magnetic resonance imaging analysis of tumors in halofuginone-treated animals showed a significant reduction of vascular functionality. Immunohistochemical studies revealed decreased collagen type I levels and vascular density in treated tumors and gelatinase assays of tumor extracts revealed a reduction of MMP-2 and MMP-9 activity in halofuginone-treated cells. Taken together, our data indicate that therapy directed at blocking MMP activity (presumably related to excessive VEGF expression in VHL) and reduction of type I collagen deposition curtails angiogenesis and thereby presumably tumor growth in this model system.

Allogeneic cell-mediated immunotherapy of leukemia with immune donor lymphocytes to upregulate antitumor effects and downregulate antihost responses

Donor lymphocyte infusion mediates most effective graft- versus-leukemia (GVL) effects following induction of host-versus-graft tolerance by transplantation of donor stem cells. This study was designed to maximize GVL effects across both major (MHC) and minor (mHgs) histocompatibility barriers in recipients inoculated with murine B-cell leukemia (BCL1), using specifically immune donor lymphocytes. GVL effects were induced with donor spleen cells from mice immunized across MHC or mHgs barriers with BCL/1 cells or normal BALB/c spleen cells. Our data suggest that spleen cells from donor mice immunized against murine B-cell leukemia of BALB/c origin, or to a lesser extent against normal host alloantigens, induce better therapeutic GVL effects with less great-versus-host disease (GVHD) across both mHgs and MHC. The cytokine profile of effector cells inducing predominantly GVL effects with reduced GVHD across MHC and mHg barriers consisted preferentially of upregulated IFN-gamma, IL-2, IL-10 and IL-12 in donors, implying a Th-1 to Th-2 cytokine shift. We hypothesize that immunotherapy with immune donor lymphocytes sensitized in vivo or in vitro with allogeneic tumor cells or normal host cells together with allogeneic BMT may provide an effective approach for amplifying GVL effects, while reducing procedure-related morbidity and mortality due to uncontrolled GVHD.

LR-90 a new advanced glycation endproduct inhibitor prevents progression of diabetic nephropathy in streptozotocin-diabetic rats

AIMS/HYPOTHESIS

Advanced glycation and lipoxidation endproducts have been implicated in the pathogenesis of diabetic complications, including diabetic nephropathy. LR-90, a new advanced glycation endproduct inhibitor, was investigated for its effects on the development of renal disease in diabetic rats.

METHODS

Diabetic animals were randomly allocated into groups receiving LR-90 or vehicle (untreated). Age- and weight-matched non-diabetic rats were studied concurrently. Body weight, plasma glucose, glycated haemoglobin, urinary albumin and creatine excretions were measured serially. Kidney histopathology, AGE accumulation in cells and tissues, protein oxidation, were also examined. In vitro assays were used to assess the possible mechanism of action of LR-90.

RESULTS

LR-90 inhibited the increase in albumin and creatinine concentrations, and concentrations of circulating AGE in diabetic rats without any effect on glycaemic control. LR-90 treated-rats also showed higher body weights than untreated diabetic rats. LR-90 prevented glomerulosclerosis, tubular degeneration and collagen deposition in the kidney. AGE-induced cross-linking and fluorescence of tail collagen were reduced by LR-90 treatment. LR-90 also decreased AGE accumulation in kidney glomeruli and nitrotyrosine deposition in the renal cortex. In vitro, LR-90 was capable of reacting with reactive carbonyl compounds and was a more potent metal chelator than pyridoxamine and aminoguanidine.

CONCLUSION/INTERPRETATION

LR-90 reduces in vivo AGE accumulation, AGE-protein cross-linking and protein oxidation, and could be beneficial in preventing the progression of diabetic nephropathy. The AGE inhibitory and therapeutic effects of LR-90 could be attributed, at least in part, to its ability to react with reactive carbonyl species and/or potent metal chelating activity that inhibits glycoxidative-AGE formation.

Immunotherapy of hematologic malignancies and metastatic solid tumors in experimental animals and man

New approaches are needed for maximizing specific responses against tumor cells resistant to chemotherapy. While cytokine therapy may amplify natural resistance against minimal residual disease, more robust anti-leukemia reactivity can be provided by allogeneic bone marrow transplantation (BMT) in conjunction with myeloablative, hence hazardous, conditioning, at the cost of graft-versus-host disease (GVHD). Documentation of the capacity of donor lymphocyte infusion (DLI) given late post BMT, when patients were off immunosuppression, in early 1987, with successful reversal of relapse and cure of patients fully resistant to maximally tolerated doses of chemoradiotherapy, with many patients alive and well >10-15 years later, indicated two important facts. First, resistant tumors are unlikely to be cured with higher doses of chemoradiotherapy that may harm the patient but not eliminate all his clonogenic tumor cells. Second, that under condition of tolerance to donor alloantigens, DLI may provide a cure to otherwise resistant patients. These observations paved the road for clinical application of non-myeloablative stem cell transplantation (NST), in the early 90s, based on a two-step procedure, first involving induction of transplantation tolerance to donor alloantigens by engraftment of donor stem cells, following safe lymphoablative rather than myeloablative conditioning. Second, use of donor lymphocytes for elimination of residual tumor or otherwise abnormal hematopoietic cells by immune-mediated graft-versus-host effects inducible by mobilized blood stem cell allografts containing larger inocula of donor T cells, or supported by post-grafting DLI when patients were off immunosuppressive modalities.

Rabbit calvarial wound healing by means of seeded Caprotite scaffolds

Autologous bone is the most successful bone-grafting material; however, limited supply and donor site morbidity are problematic. Synthetic bone substitutes are effective, but healing is slow and unpredictable. Osseous wound healing may be enhanced if bone substitutes are combined with autologous bone marrow cells. To test this hypothesis, we created 40 calvarial defects in 20 12-week-old New Zealand White rabbits, divided into four groups: (1) unrepaired controls, (2) autologous bone grafts, (3) unseeded Caprotite (a polymer-ceramic composite) grafts, and (4) Caprotite grafts seeded with autologous bone marrow stromal cells. CT scans were obtained at 0, 6, and 12 weeks post-operatively, and defects were harvested for histology. Defects repaired with autologous bone had significantly (p < 0.05) more bone than the other three groups, although seeded Caprotite defects showed different wound-healing sequelae. Results suggest that seeded Caprotite scaffolds did not significantly enhance osseous defect healing compared with controls.

Fludarabine in combination with cyclophosphamide decreases incidence of GVHD and maintains effective graft-versus-leukemia effect after allogeneic stem cell transplantation in murine lymphocytic leukemia

Graft-versus-host disease (GVHD) is a severe disorder and despite therapeutic efforts to decrease its distressing clinical manifestations, treatment is still not optimal. Here we report the results of studies, in which the purine analogue, fludarabine phosphate, was used in an attempt to modify and decrease GVHD after stem cell transplantation, across major histocompatibility barriers for murine leukemia. B-cell leukemia (BCL-1) bearing (BALB/c x C57BL/6) F1 mice received two cycles of fludarabine (0.8 mg/kg) for 5 days every 2 weeks, followed by 400 mg/kg cyclophosphamide i.p. Animals were then transplanted with C57BL/6 precursor cells and the development of leukemia and extent of GVHD was monitored both clinically and histopathologically. In the fludarabine-treated group, only nine of 28 (32%) mice developed leukemia, compared to 25 of 33 (76%) of control animals (P=0.0006 ). Mice treated with fludarabine-containing regimens prior to transplantation also had much less GVHD both clinically and at autopsy, while graft-versus-leukemia appeared to be augmented in the same animals.

Linomide administration following bone marrow transplantation in mice

The effect of linomide, an immunomodulatory drug, on natural killer (NK) cells and T cell-dependent immune responses following syngeneic or allogeneic bone marrow transplantation (BMT) was investigated in BALB/c mice inoculated with B-cell leukemia (BCL1). Linomide given in the drinking water had no impact on graft survival or graft versus leukemia (GVL) effects. Although linomide regulates anti-self reactivity in mice with experimental and spontaneous autoimmune disorders, the anti-tumor effects induced by allogeneic donor lymphocytes were not affected. This indicates that different mechanisms regulate anti-self and anti-leukemia effects. Alternatively, linomide might affect the homing of self-reactive lymphocytes to specific target organs in autoimmune disorders, although the homing process may not be relevant to the control of leukemia by alloreactive lymphocytes.

[Role of gastroesophageal reflux in asthma in infants and young children]

Gastroesophageal reflux (GER) occurs more frequently in asthmatic children than in general population. Esophageal pH recording data may be somewhat particular. The debate on GER increasing bronchial obstruction or GER being a parallel phenomenon remains controversial. Hypotheses are: acid microaspirations giving bronchospasm, vagally-transmitted reflex, or more probably coexisting phenomena. Pulmonary contamination is rarely seen during esophageal scintigraphy. Asthma symptoms are rarely clearly correlated to acid reflux episodes in pH-recording studies. However the esophageal acid infusion test may increase bronchial obstruction in adult asthmatics. Basically, when should one seek GER in asthmatic children? Many authors keep this for asthmatic children not responding to conventional treatment, also keeping in mind that GER-specific therapy efficacy is often difficult to appreciate in such patients. Briefly, one may speculate that GER improves with bronchodilator treatment in most cases.

Cytokine production in Linomide-treated nod mice and the potential role of a Th (1)/Th(2) shift on autoimmune and anti-inflammatory processes

Linomide prevents the development of autoimmune insulitis and insulin-deficient diabetes mellitus in female NOD mice. Linomide prevents development of autoimmune manifestations in other experimentally induced and spontaneous autoimmune diseases as well, but the mechanism of action is unknown. The present report summarizes our investigations on the effect of Linomide on different functional T cell subsets in NOD mice analyzed according to their cytokine profile. Supernatants from cultured splenocytes and peritoneal cells taken from Linomide-treated mice contained lower levels of TNFalpha, IL-1 beta, IFN gamma and IL-12 versus higher levels of IL-4, IL-6 and IL-10 in comparison with supernatants from cultures of untreated mice. Our results suggest that regulation of autoimmunity following oral Linomide administration in NOD mice induces a shift from Th(1) to Th(2) phenotype response, thereby preventing the development of diabetes by active cytokine-induced immunoregulation of T cell subsets, including downregulation of Th(1) and upregulation of Th(2).

Donor lymphocyte infusion: the use of alloreactive and tumor-reactive lymphocytes for immunotherapy of malignant and nonmalignant diseases in conjunction with allogeneic stem cell transplantation

Donor lymphocyte infusion (DLI), pioneered in Jerusalem in January 1987, represents the first proof of principle of the absolute efficacy of immunotherapy as a means of curing cancer. Immunotherapy with alloreactive donor lymphocytes can eliminate "the last tumor cell" even in patients with hematological malignancies resistant to maximally tolerated doses of chemoradiotherapy. Alloreactive lymphocytes that can mediate anti-tumor effects following induction of host-versus-graft tolerance induced by transplantation of donor stem cells, can induce graft-versus-malignancy (GVM) effects which are usually accompanied by graft-versus-host disease (GVHD). However, occasionally GVM effects may also be accomplished independently of clinically overt GVHD. Interestingly, allogeneic donor lymphocytes may also eliminate undesirable host-derived hematopoietic cells in a large number of nonmalignant indications including genetic diseases, diseases caused by deficiency of stem cell products, and autoimmune disorders mediated by self-reactive lymphocytes. The cumulative clinical experience suggests feasibility of effective induction of graft-versus-leukemia (GVL); graft-versus-lymphoma (GVLy); graft-versus-multiple myeloma, as well as graft-versus-solid tumors (GVT), well-documented in patients with renal and breast cancer, even in patients with resistant disease that have failed myeloablative chemoradiotherapy. These observations that suggested that cell therapy by donor lymphocytes is the main therapeutic benefit of bone marrow transplantation (BMT) led to development of the nonmyeloablative approach for safer allogeneic stem cell transplantation. Nonmyeloablative stem cell transplantation (NST) makes it possible to offer an option for cure to elderly patients with no upper age limit, as well as to patients with poor performance status not considered eligible for conventional BMT. Using well-tolerated NST regimen, allogeneic stem cell transplantation can be accomplished with minimal procedure-related toxicity and mortality, possibly even on an outpatient basis. Immunotherapy mediated by adoptive allogeneic cell-mediated immunotherapy can be further improved by utilizing specifically immune donor lymphocytes, thus maximizing their efficacy against undesirable target cells of host origin on the one hand, while minimizing their ontoward efficacy against normal cells of host origin that could result in GVHD on the other. Taken together, DLI and subsequently NST, may have opened new horizons for treatment of life-threatening malignant and nonmalignant disorders correctable by allogeneic stem cell transplantation. It is anticipated that further improvement of reactivity and specificity of donor lymphocytes will lead to safer clinical application of cell therapy for a larger number of indications toward improving disease-free survival in a large number of indications while minimizing immediate and late procedure-related complications.

Intramedullary abscess resulting from disseminated cryptococcosis despite immune restoration in a patient with AIDS

We report on a case of cryptococcal intramedullary abscess, which occurred three years after a disseminated cryptococcosis and two years after a lymph node cryptococcal recurrence in a HIV-infected patient who exhibited a long-standing immune restoration. At the time of diagnosis, CD4(+) lymphocyte-count was 640x10(6)/l and HIV viral load was undetectable. Spinal involvement is rare during cryptococcosis of the central nervous system. As far as we are aware, there is only one case of proven intramedullary cryptococcal abscess reported in the literature and this case is then the second one. The significant and sustained increase in CD4 count following effective antiretroviral therapy was probably associated with only a partial immune restitution that did not allow to avoid the occurrence of the cryptococcal medullar abscess. Finally, this case raises the question of when to stop secondary prophylaxis of cryptococcal disease after increase in CD4 cell count under antiretroviral therapy.

Preferential accumulation of (3)H-tetraphenylphosphonium in non-small cell lung carcinoma in mice: comparison with (99m)Tc-MIBI

We have previously shown enhanced accumulation of the delocalized lipophilic cation (11)C-triphenylmethylphosphonium in canine brain glioma, suggesting its potential use for tumor staging in humans using PET. Here, we extend our studies of phosphonium cations to nonbrain tumors and characterize the biodistribution and tumor specificity of (3)H-tetraphenylphosphonium ((3)H-TPP) in non-small cell lung carcinoma in mice.

METHODS

(3)H-TPP accumulation in isolated malignant lung nodules of the Lewis lung carcinoma (LLC) cell line, in LLC-bearing lung, and in control lung was measured at various intervals after inoculation. Tumor uptake and biodistribution of (3)H-TPP were compared with those of (99m)Tc-methoxyisobutylisonitrile (MIBI).

RESULTS

(3)H-TPP accumulation in LLC nodules at 14 d was significantly greater than that in controls, peaked at 21 d, and declined to lower values at 28 d after injection. At 21 d after injection, (3)H-TPP uptake in LLC nodules was greater than that in control lung tissue and in LLC-bearing lung tissue-by 549% and 230%, respectively-whereas (99m)Tc-MIBI nodule uptake was greater by 90% and 30%, respectively.

CONCLUSION

The high tumor accumulation and sensitivity to the phase of tumor development suggest the potential use of radiolabeled phosphonium analogs for in vivo tumor staging and as a tool for investigating tumor evolution.

Flexible dosing schemes for recombinant human erythropoietin--lessons from our daily practice

The availability of recombinant human erythropoietin (rh-Epo) has revolutionized the treatment of renal anaemia. Subcutaneous (s.c.) administration of rh-Epo offers significant advantages over the intravenous (i.v.) route, and numerous studies have demonstrated its efficacy and tolerability when administered two or three times weekly. Most of these studies showed a significant reduction in rh-Epo dosage requirements with s.c. administration compared with the i.v. route, offering clear benefits in terms of reduced costs. In addition, s.c. administration is more convenient and flexible than i.v. administration, and is recommended by European and US guidelines. Dosing frequency of rh-Epo is also an important issue in clinical practice, particularly when customizing therapy to meet individual patient needs. A few small-scale studies have shown comparable efficacy and tolerability of different s.c. dosing frequencies. Recently, a comprehensive randomized controlled trial has shown that once weekly s.c. epoetin beta effectively manages anaemia in haemodialysis patients, even in patients requiring a high dose. Once weekly dosing of s.c. epoetin beta adds greater flexibility and an improved capacity to tailor dosing frequency to patient needs. This reduces clinic time for patients who do not self-administer and, together with improved convenience of new formulations and delivery systems, has the potential to improve compliance and encourages self-administration.

Immunological and virological features of HIV-infected patients with increasing CD4 cell numbers despite virological failure during protease inhibitor-based therapy

OBJECTIVES

To investigate the extent of functional T cell recovery and to characterize plasma virus and virus producing cells in patients with increasing CD4 cell counts despite virological failure during protease inhibitor (PI) based therapy.

METHODS

The study group included 13 patients who were treated for at least 12 months with a PI based regimen and were selected on the basis of a sustained immunological response (increase of > 70 CD4 cells/microL) despite virological failure (< 1 log10 copies/mL decrease in HIV-1 RNA plasma levels).

RESULTS

Compared to a historical series of 11 complete responders with less advanced disease, the proportion of memory CD4 T cells was significantly higher (67.8+/-17.8 vs. 52.8+/-11.0; P=0.045) and the proportion of naive CD4 T cells significantly lower (30.5+/-14.8 vs. 45.0+/-10.4, P=0.021) in patients who were immunological responders/virological nonresponders. In those patients, ongoing viral replication was associated with a strong activation of circulating CD8 T lymphocytes; interleukin-2 production remained decreased. CD4 T cell reactivity to cytomegalovirus proteins was observed in nine of 11 patients tested. In the study group, the proportion of infectious virus present in plasma as well as the levels of intracellular viral replication were similar to those measured in untreated patients. Virological failure in this group of patients probably resulted from pre-existing mutations in the reverse transcriptase gene.

CONCLUSIONS

This study of patients with increasing CD4 cell numbers despite virological failure shows the persistence of immune activation and partial immune restoration with no evidence of specific viral dynamics in vivo.

Autocrine production of interleukin 6 causes multidrug resistance in breast cancer cells

It has been shown that serum levels of interleukin (IL)-6 are elevated in patients with various types of cancer. However, the exact source of IL-6 in these patients and its role in tumor progression remain unclear. Here we demonstrate that the autocrine production of IL-6 by tumor cells promotes resistance of the cells to chemotherapy, a novel function of IL-6 in cancer biology. Breast cancer cells that are sensitive to drug treatment do not express IL-6, whereas high levels of IL-6 are produced by multidrug-resistant breast cancer cells. Expression of the IL-6 gene in drug-sensitive breast cancer cells increases their resistance to drug treatment by activating the CCAAT enhancer-binding protein family of transcription factors and inducing mdr1 gene expression. Thus, the autocrine production of IL-6 by tumor cells is an important factor in determining the susceptibility or resistance of these cells to drug treatment. Because tumors from some breast cancer patients contain IL-6-producing cells, it is possible that IL-6 could potentially be used as a prognostic factor for chemotherapy resistance.

West Nile fever in Israel 1999-2000: from geese to humans

West Nile virus (WNV) caused disease outbreaks in Israel in the 1950s and the late 1970s. In 1998 an outbreak of WNV in goose farms and evidence of infection in dead migratory birds were reported. Consequently, human diagnostic services for WNV were resumed, including virus isolation, serology, and RT-PCR. Risk factors for infection were assessed by a serological survey in 1999, which revealed a seroprevalence of (a) 86% in people who had close contact with sick geese, (b) 28% in people in areas along bird migration routes, and (c) 27% in the general population. Following two fatal cases in Tel Aviv in September 1999 and one encephalitis case in the southern Eilot region, a regional serological survey was initiated there. The survey revealed two more WNV-associated acute encephalitis cases, an IgG seroprevalence of 51%, and an IgM seroprevalence of 22%. In the summer of 2000, acute cases of WN disease were identified in the central and northern parts of Israel, involving 439 people. The outbreak started in mid-August, peaked in September, and declined in October, with 29 fatal cases, primarily in the elderly. During the outbreak, diagnosis was based on IgM detection. Four virus isolates were subsequently obtained from preseroconverted frozen sera. Sequence and phylogenetic analysis of 1662 bases covering the PreM, M, and part of the E genes revealed two lineages. One lineage was closely related to a 1999 Israeli bird (gull) isolate and to a 1999 New York bird (flamingo) isolate, and the other lineage was closely related to a 1997 Romanian mosquito isolate and to a 1999 Russian human brain isolate.

[Primary pulmonary hypertension in human immunodeficiency virus infection. Study of 9 cases amd review of the literature]

PURPOSE

In medical literature, primary pulmonary hypertension occurs in 0.5% of human immunodeficiency virus (HIV)-infected patients, irrespective of the stage of the HIV disease, and is more frequent in drug users. Plexogenic arteriopathy is the most frequent histological lesion.

METHODS

We retrospectively report on nine cases of primary pulmonary hypertension during HIV infection.

RESULTS

The subjects were four women and five men, mean age 38 years old. Four of them had been sexually contaminated and five had contracted the disease through intravenous drug use. At the time primary pulmonary hypertension was diagnosed, mean CD4 cell count was 234 +/- 217/mm3 and the viral load was low or undetectable. Primary pulmonary hypertension has been diagnosed an average of 7 months after the first cardiovascular clinical signs had started. Despite anti-coagulant (7/9 cases), vasodilatator (4/9 cases) and/or diuretic (7/9 cases) therapy, the progression of the disease quickly turned out to be negative (seven deaths).

CONCLUSION

Diagnosis of primary pulmonary hypertension should be considered when unexplained dyspnea occurs in an HIV-positive patient. At initial evaluation, alterations of hemodynamic parameters are usually less severe than during idiopathic primary pulmonary hypertension, but their progression is quicker and more severe, independent of the patient's immune status. Current data do not allow the determination of whether antiretroviral therapy is active in primary pulmonary hypertension evolution. Therapeutic evaluation with prostacyclin is currently being carried out. While the life expectancy of HIV-infected patients extends, primary pulmonary hypertension occurrence could increase and call for early diagnosis, thus allowing for specific care.