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Biomedical subjects

M Cherchi

Publications and source records attributed to M Cherchi.

12 recordsLinked to original sources
PubMed1992

Absence of antibodies to human herpesvirus-6 in patients with slowly-progressive human immunodeficiency virus type 1 infection.

To evaluate a possible role for Human Herpesvirus-type 6 (HHV-6) coinfection as a co-factor in the progression of HIV-1 disease, we investigated the prevalence of seropositivity for HHV-6 in a cohort of HIV-1 infected patients. These patients were retrospectively divided into two groups according to the decline of CD4+ T cells during the follow up: 11 were classified as rapid decliners (less than 400 CD4+/cmm within 1 year), and 38 as slow decliners (greater than 400 CD4+/cmm after at least 4 years' follow up). HHV-6 antibodies were detected by a commercial immunofluorescence assay and by a Western blotting assay developed in our laboratory. Our results show that Western blot appears to provide results satisfactorily free of false positivities. We found that the frequency of HHV-6 seropositivity was significantly lower in the group of slow decliners, compared both to rapid decliners and to the general population. These data suggest a role for HHV-6 co-infection in the progression of HIV-1 disease.

Adolescent↗
PubMed1992

T-lymphocyte reactivity to the recombinant mycobacterial 65- and 70-kDa heat shock proteins in multiple sclerosis.

Owing to their conservation and immunogenicity, heat shock proteins (hsps) represent a class of potential autoantigens. Moreover, they could be targets for gamma delta T lymphocytes, which are prominent in various immune disorders. We studied the T cell proliferative primary responses to recombinant M. bovis 65 kDa hsp (hsp65) and M. tuberculosis 70 kDa hsp (hsp70) in 31 patients with multiple sclerosis (MS), 19 patients with other neurological diseases (OND) and 19 healthy individuals. Positive responses to hsp70, but not to hsp65 were significantly more frequent in patients with MS than in patients with OND or in healthy individuals. In order to verify and refine these results and to characterize the hsp reactive T lymphocytes, we screened 147 PPD-specific long-term T cell lines (76 from 10 patients with MS and 71 from 12 healthy donors) for their proliferative response to hsp65 and hsp70. hsp70-reactive T lines were significantly more common in patients with MS than in healthy controls. The number of T lines responding to hsp65 increased in the MS group only slightly. In 19 T lymphocyte lines from patients with MS and healthy donors, a cytofluorometric analysis was performed with special attention paid to distinct T cell receptor gamma delta determinants. With one exception, in each line the population of gamma delta T cells remained a minority. We conclude that an increased T cell response to mycobacterial hsp70 may be present in patients with multiple sclerosis.

Adolescent↗
PubMed1979

Clinical staging and immunological findings in chronic lymphocytic leukemia.

Several immunological markers were tested in 52 untreated cases of chronic lymphocyte leukemia (CLL) to see whether their frequency differed according to the clinical stage in Rai's system. The leukemic cells in all cases had B-cell features as shown by monoclonal immunoglobulins on the cell surface (SmIg) and/or a high percentage of mouse RBC (M)-rosettes. Of the two B-cell markers, the M-rosette test was the more consistently positive. The frequency of these markers did not correlate with clinical staging. The percentage of T-lymphocytes, low in all cases, was found to correlate inversely with the lymphocyte counts, which were higher in advanced stages. The absolute number of T-lymphocytes was above normal in most cases, but did not relat to staging. At least one of the serum Ig, most commonly IgA, was decreased in 87% of cases. Low Ig were slightly less common in Stages 0-I than in advanced stages (II-IV). The above features were also examined in two groups of CLL patients: with stable (9) or progressive (16) disease. The only difference observed between the two groups was that surface IgM only was present in 1 of the 9 stable cases as compared to 9 of the 16 progressive ones. Our findings do not support the suggestions that surface IgM is a feature of a benign form of CLL or that the absolute number of T-lymphocytes correlates with prognosis.

Adult↗
PubMed1979

'Prolymphocytoid' transformation of chronic lymphocytic leukaemia.

We report clinical, morphological and surface marker studies on seven patients with the common type of chronic lymphocytic leukaemia (CLL) whose disease underwent an insidious though progressive change in character with increasing refractoriness to treatment. This transformation was accompanied by the appearance of a population of immature-appearing cells in the peripheral blood which resembled prolymphocytes, both at light and electron microscopy. The characteristic morphological feature was the presence of two distinct populations of cells, the typical CLL lymphocytes and the 'prolymphocytoid' cells. These cells retained the surface characteristics of CLL, i.e. the information of mouse RBC rosettes and sparse surface-bound immunoglobulin. This transformation can be distinguished by morphological and surface marker criteria from acute leukaemia occurring in CCL, Richter's syndrome and prolymphocytic leukaemia. The recognition of this group of CLL patients may add a new prognostic index to CLL and may help plan subsequent trials for the treatment of the disease.

Aged↗
PubMed1978

Ultrastructural, cytochemical and surface marker analysis of cells during blast crisis of chronic granulocytic leukaemia.

The blast cells of 19 patients with Ph1-positive chronic granulocytic leukaemia (CGL) in blast crisis (BC) were studied by means of several techniques: morphology, cytochemistry, ultrastructure, surface markers and the enzyme terminal transferase. Cells of BC were, in most case, extremely undifferentiated by morphology and cytochemistry. Our data showed that in 80% of cases the cells in BC were myeloid and in 20% they were "lymphoblastic". The M1, M2 and M3 forms (FAB classification) were rare in CGL BC compared with acute myeloid leukaemia (AML). A megakaryoblastic type was seen in 15% of BC cases; the existence of this form could only be demonstrated by electron microscopy. The limphoblastic BC cells were, as in acute lymphoblastic leukaemia (ALL), positive with Greaves' anti-ALL serum and had elevated levels of terminal transferase. A case of a 17-year old boy presenting as ALL, reverting to chronic-phase CGL after complete remission and developing terminally a myeloid BC is described in detail. This case helps to illustrate a new form of natural history of CGL unveiled by the present study.

Adolescent↗
PubMed1978

Acid-phosphatase reaction in acute lymphoblastic leukaemia.

The diagnostic value of the acid-phosphatase reaction was assessed double-blind in 148 cases of acute lymphoblastic leukaemia (A.L.L.) classified by surface-membrane markers and entered into the M.R.C. U.K. A.L.L. trials. 90% of cases of T-A.L.L. showed a positive reaction in the majority of blast cells, while only 2% of common-A.L.L. and 10% of null-A.L.L. were positive. This cytochemical reaction distinguished the more aggressive form of A.L.L. any may aid the choice of therapy.

Acid Phosphatase↗
PubMed1977

Phagocytic potential of leukaemic B-lymphocytes.

Phagocytosis of small latex particles was demonstrated by light and electron microscopy in a proportion of cells from B-lymphoproliferative disorders including chronic lymphocytic, prolymphocytic and hairy cell leukaemia. It was not observed in a case of T-chronic lymphocytic leukaemia or in normal lymphocytes. A significant correlation was observed between the binding of latex to the lymphocyte surface and the degree of phagocytosis. It is suggested that the phagocytic activity of leukaemic B-lymphocytes is mediated through their Fc receptor and that this property may also be present in normal B-cells. Among mononuclear cells, therefore, phagocytosis can no longer be considered exclusively a property of monocytes.

B-Lymphocytes↗
PubMed1976

5' nucleotidase activity in leukaemic lymphocytes.

The enzyme 5' nucleotidase (E.C.3.1.3.5.) is present in lymphocytes isolated from the blood of normal subjects. The activity was extremely low in lymphocytes from 17 patients with B lymphocytic leukaemias. Removal of normal lymphocytes from the B-cell leukaemic samples decreased further the enzyme activity. Moderately low values were observed in three cases of T-ALL and in the cells from a case of Sézary syndrome. In contrast, normal or high values were observed in three cases of ALL in which T and B markers were not demonstrable and in two of T-CLL. No differences were observed in partially purified subpopulations of normal B and T cells.

B-Lymphocytes↗
PubMed1976

Mouse red-cell rosettes in B-lymphoproliferative disorders.

A high proportion of peripheral-blood lymphocytes formed spontaneous rosettes with mouse red cells in 22 out of 23 cases of chronic lymphocytic leukaemia (CLL); the proportion was significantly higher than in 19 cases of other B-lymphoproliferative disorders (non-CLL group) and in 19 normal controls. Intermediate findings were obtained in 10 cases of "hairy" cell leukaemia. Blast cells from various types of acute leukaemia did not bind mouse red cells. Pre-treatment of the lymphocytes with neuraminidase led to a significant increase in the proportion of rosettes in CLL only. This test may prove useful in distinguishing CLL from other B-lymphoproliferative disorders, particularly prolymphocytic leukaemia.

Animals↗