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D Sicard

Publications and source records attributed to D Sicard.

At least 55 records · Page 3Linked to original sources
PubMed1999

Broad, intense anti-human immunodeficiency virus (HIV) ex vivo CD8(+) responses in HIV type 1-infected patients: comparison with anti-Epstein-Barr virus responses and changes during antiretroviral therapy.

The ex vivo antiviral CD8(+) repertoires of 34 human immunodeficiency virus (HIV)-seropositive patients with various CD4(+) T-cell counts and virus loads were analyzed by gamma interferon enzyme-linked immunospot assay, using peptides derived from HIV type 1 and Epstein-Barr virus (EBV). Most patients recognized many HIV peptides, with markedly high frequencies, in association with all the HLA class I molecules tested. We found no correlation between the intensity of anti-HIV CD8(+) responses and the CD4(+) counts or virus load. In contrast, the polyclonality of anti-HIV CD8(+) responses was positively correlated with the CD4(+) counts. The anti-EBV responses were significantly less intense than the anti-HIV responses and were positively correlated with the CD4(+) counts. Longitudinal follow-up of several patients revealed the remarkable stability of the anti-HIV and anti-EBV CD8(+) responses in two patients with stable CD4(+) counts, while both antiviral responses decreased in two patients with obvious progression toward disease. Last, highly active antiretroviral therapy induced marked decreases in the number of anti-HIV CD8(+) T cells, while the anti-EBV responses increased. These findings emphasize the magnitude of the ex vivo HIV-specific CD8(+) responses at all stages of HIV infection and suggest that the CD8(+) hyperlymphocytosis commonly observed in HIV infection is driven mainly by virus replication, through intense, continuous activation of HIV-specific CD8(+) T cells until ultimate progression toward disease. Nevertheless, highly polyclonal anti-HIV CD8(+) responses may be associated with a better clinical status. Our data also suggest that a decrease of anti-EBV CD8(+) responses may occur with depletion of CD4(+) T cells, but this could be restored by highly active antiretroviral treatment.

Antiviral Agents↗
PubMed1998

Acquired hemophilia due to factor VIII inhibitors in 34 patients.

BACKGROUND: Acquired hemophilia is a rare disease caused by the development of auto-antibodies against factor VIII. SUBJECTS AND METHODS: We studied the characteristics and outcomes of 34 patients (19 women and 15 men) with acquired hemophilia from 1980 to 1997. RESULTS: The mean age of the patients was 61 years (range, 22-93 years). An underlying disease was observed in 18 (53%) patients: 5 patients had cancer, 4 an autoimmune disorder, 2 a dermatologic disorder, 3 asthma, 3 were postpartum, and 1 had an adverse reaction to ampicillin. Factor VIII level was <5% in 30 (90%) patients; factor VIII antibodies were elevated (>10 Bethesda units) in 23 (69%) patients. Bleeding requiring transfusions was reported in 25 (75%) patients. Human factor VIII was given to 14 patients and porcine factor VIII to 5. Six patients received prothrombin complex concentrates and one desmopressin. Several immunosuppressive treatments were used, mainly corticosteroids, cyclophosphamide, and intravenous immunoglobulin. Bleeding stopped in all but one patient within 2 weeks. Most patients achieved complete remission, although two relapses were observed subsequently. CONCLUSION: This large study helps to clarify the presentation and clinical course of acquired hemophilia. Prospective studies are needed to determine the efficacy of treatment.

Adult↗
PubMed1998

Muscular bacillary angiomatosis in AIDS.

We describe an unusual case of bacillary angiomatosis first misdiagnosed as Kaposi's sarcoma in muscle in a patient with HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1998

Detection of HIV-1 in seminal plasma and seminal cells of HIV-1 seropositive men.

It is of critical importance to precisely understand the modalities of HIV presence in semen, especially with regard to procreation. In this study, paired blood and semen samples from 31 human immunodeficiency virus type 1 (HIV-1)-positive men were assessed for cell-free HIV-RNA load in blood plasma (BP) and seminal plasma (SP), and for detection of HIV by culture, PCR and RT-PCR in semen cellular fractions separated by centrifugation on Percoll gradient. HIV-RNA was detected in 94% of BP and 84% of SP samples. For 11 men (35%), HIV-RNA load in SP was equal or superior to that observed in blood. HIV-DNA presence was demonstrated (either by PCR or culture positivity) in 39% of the non-spermatozoal cells (NSC)-enriched fractions, and in one Percoll-selected sperm pellet. HIV-RNA was detected in 17% (4/23) of the sperm pellets. This positivity was associated with an HIV-RNA load in SP equal or superior to the HIV-RNA load in blood, a high rate of HIV-DNA detection in the NSC fraction, and a low CD4+ cell count. In such conditions, a significant viral production inside the genital tract is more likely to be present, and a close association between HIV and gametes might occur. Assisted procreation with selected spermatozoa should be preceded by accurate assessments of viral presence in blood, SP and semen cellular fractions.

Cell Fractionation↗
PubMed1998

[Peripheral adrenal insufficiency in AIDS].

BACKGROUND: Lesions of adrenal glands are common findings at autopsy of patients with acquired immunodeficiency syndrome (AIDS). In contrast the diagnosis of symptomatic adrenal insufficiency is rarely established during the lifetime of these patients. PATIENTS: We report four new cases and review the literature. All four patients had full blown AIDS with a mean CD4 cell count of 19 mu/L. One or more opportunistic disease was present at the time of diagnostic: cytomegalovirus retinitis in two cases, disseminated Mycobacterium avium infection in two, Kaposi's sarcoma in two and Candida esophagitis in one. RESULTS: The clinical presentation constantly included fatigue, weight loss, severe orthostatic hypotension and gastrointestinal disturbances. Cutaneous hyperpigmentation was present in three cases. In most cases biological abnormalities were typical, such as hyponatremia, urinary Na/K ratio > or = 1, and hyperkalemia. Serum cortisol levels were within the range of normal in three cases but response to the cosyntropin challenge was typically impaired in all cases. Clinical and biological manifestations returned to normal in 1 to 3 weeks after initiation of therapy with cortisol, associated to fludrocortisone in three cases. However, 13 months after diagnosis, three patients were dead. CONCLUSION: Usually asymptomatic, diagnostic of symptomatic adrenal insufficiency must be suspected even when clinical presentation is atypical because rapid efficiency of hormonal treatment.

AIDS-Related Opportunistic Infections↗
PubMed1998

HIV combination therapy: immune restitution causing cryptococcal lymphadenitis dramatically improved by anti-inflammatory therapy.

Two patients with AIDS developed microscopically verified focal cryptococcal lymphadenitis while treated with highly active anti-retroviral therapy for 8 and 15 months. Both were treated with fluconazole as a secondary prophylaxis for prior cryptococcal meningitis. Cryptococcus neoformans did not grow. Amphotericin was ineffective. Anti-inflammatory drugs had a dramatic effect.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Cross-reactions between the cytotoxic T-lymphocyte responses of human immunodeficiency virus-infected African and European patients.

The great variability of protein sequences from human immunodeficiency virus (HIV) type 1 (HIV-1) isolates represents a major obstacle to the development of an effective vaccine against this virus. The surface protein (Env), which is the predominant target of neutralizing antibodies, is particularly variable. Here we examine the impact of variability among different HIV-1 subtypes (clades) on cytotoxic T-lymphocyte (CTL) activities, the other major component of the antiviral immune response. CTLs are produced not only against Env but also against other structural proteins, as well as some regulatory proteins. The genetic subtypes of HIV-1 were determined for Env and Gag from several patients infected either in France or in Africa. The cross-reactivities of the CTLs were tested with target cells expressing selected proteins from HIV-1 isolates of clade A or B or from HIV type 2 isolates. All African patients were infected with viruses belonging to clade A for Env and for Gag, except for one patient who was infected with a clade A Env-clade G Gag recombinant virus. All patients infected in France were infected with clade B viruses. The CTL responses obtained from all the African and all the French individuals tested showed frequent cross-reactions with proteins of the heterologous clade. Epitopes conserved between the viruses of clades A and B appeared especially frequent in Gag p24, Gag p18, integrase, and the central region of Nef. Cross-reactivity also existed among Gag epitopes of clades A, B, and G, as shown by the results for the patient infected with the clade A Env-clade G Gag recombinant virus. These results show that CTLs raised against viral antigens from different clades are able to cross-react, emphasizing the possibility of obtaining cross-immunizations for this part of the immune response in vaccinated individuals.

Base Sequence↗
PubMed1998

[Acyclovir-resistance zona in a immunocompromised HIV seronegative patient].

INTRODUCTION: Resistance to antiviral therapy is getting actually more frequent. Immunocompromised host are more concerned with this problem. OBSERVATION: We present a case of disseminated zoster resisting to acyclovir (ACV) therapy, but healing with foscarnet in a man treated with chemotherapy for lymphoma and seronegative for HIV. CI50 of VZV strain was 48 microM for ACV, which was 2.8 times higher than value of the reference OKA strain tested simultaneously, which confirmed the resistance for ACV. DISCUSSION: Immunocompromised patients often present varicella zoster virus (VZV) infection. They usually heal in response to ACV therapy, but some HIV infected patients have already presented with resistant strains of VZV. This case is the first described in a non-HIV infected patient. Foscarnet therapy resulted twice in complete healing because of its direct activity on viral DNA polymerase, so it is efficaceous therapy for patients with thymidine-kinase-deficient ACV-resistant VZV infection.

Acyclovir↗
PubMed1997

[Viral load].

Explore the source record for details and available documents.

CD4 Antigens↗
PubMed1997

[Search for a HIV vaccine].

A DIFFICULT SITUATION FOR A VACCINE: The human immunodeficiency virus has an exceptional capacity to mutate and macrophage reservoirs where it is harbored after penetration are highly inaccessible to antibodies. Use of a live vaccine would increase the risk of recurrent virulence and integration into the genome. UNKNOWN IMMUNOLOGY: Induction of cytotoxic cells appears to be essential, but investigations into this type of response are not well standardized and not easily quantifiable. Neutralizing antibodies would have a protective effect, but facilitating antibodies would have the opposite effect. SEVERAL POSSIBILITIES UNDER STUDY: These vaccine use live attenuated viruses with a more or less deleted genome, recombinant live viruses constructed from other viruses or bacteria, pseudo-particles, or recombinant proteins as well as vaccines synthetized from peptides or lipopeptides. An association of different vaccines would appear to be the best solution as live vectors usually induce cytotoxic cells while proteins or peptides induce production of neutralizing antibodies. RESPONSE TO VACCINES IS USUALLY WEAK: Both in animal models and in human volunteers, immune responses obtained to date have been quite variable and of short duration. Canarypox type recombinant vaccines followed by recombinant protein vaccines appear to give the best results at the present time. SEVERAL PROBLEMS: Anti-HIV vaccination protocols raise major ethical problems for the participating volunteers (ELISA test becomes positive, lack personal protection) and for the population involved in phase II/III trials. In addition, the virus rapidly penetrates via the mucosa without yielding sufficient mucosal immune response.

AIDS Vaccines↗