A longitudinal study of the IgG antibody response to HIV-1 p17 gag protein in HIV-1+ patients with haemophilia: titre and avidity.

The IgG response to HIV-1 p17 gag protein was studied for up to 6 years in 12 HIV-1-infected patients with haemophilia, who had seroconverted between 1982 and 1985. To assess any prognostic value, p17 IgG titres were compared with p24 IgG titres, CD4 cell counts and p24 antigenaemia. p17 IgG avidity index was also examined. A strong similarity was found between the IgG titre to HIV-1 p17 and that to p24. In patients who developed AIDS the decline in p17 IgG titres could precede by several years the drop in CD4 cells to under 200 cells/microliters; whereas some long-term asymptomatic patients (CDCII) had increasing p17 IgG titres and stable CD4 cell counts. Declining p17 and p24 IgG titres were not always associated with an increase in p24 antigenaemia. IgG titres were found to be better predictors of disease progression than CD4 cell counts or p24 antigenaemia. Patients who developed AIDS during the study were also characterized by a lower p17 IgG avidity than patients who remained asymptomatic. This result suggests that IgG avidity could have prognostic relevance and be of importance for host resistance to AIDS onset.     

Demonstration of T4, T8, M1 and B7 determinants on human T cells with a rosette test: implications for the assay specificity of monoclonal antibodies

Under optimal test conditions significantly more freshly isolated human T cells reacted with OKT4, OKT8, OKM1 and OKB7 monoclonal antibodies (Mabs) in the indirect antiglobulin rosetting reaction (IARR) than by indirect immunofluorescence. Rabbit erythrocytes (E) coated with anti-mouse immunoglobulin were more sensitive indicator cells in the IARR than similarly coated sheep E. Treatment of T cells with neuraminidase further enhanced T cell reactivity in the IARR with each Mab so that an average of 60% or more of T cells were T4+, T8+ and M1+ and at least 40% had the T4+ T8+ phenotype. The various findings suggest that the rosette assay detects determinants on T cells that are expressed below the detection threshold of immunofluorescence. Moreover, these findings indicate that the cellular specificities of a particular Mab may change when one assay system is substituted for another or when the protocol of a particular assay is altered.     

Simultaneous Detection of ACP1 and GC Genotypes Using PCR/SSCP

The classical enzyme and protein markers ACP1 and GC have gained new importance because of the biological functions of their gene products. ACP1 encodes a low molecular weight enzyme which is now recognized as a phosphotyrosine phosphatase with a role in the regulation of signal transduction pathways, and GC‐globulin acts both as a transporter of vitamin D and as a plasma actin scavenger and plays a role in macrophage activation. These two polymorphisms were phenotyped for decades on the basis of electrophoretic isozyme or protein patterns; the gene structures are now known. Nucleotide substitutions determining the common alleles are close enough at each locus to be contained in one short PCR product. We have developed a simple, rapid and reliable multiplex method based on PCR and SSCP which allows the simultaneous determination of the common ACP1 and GC genotypes.     

Elevation of activated gamma delta T cell receptor bearing T lymphocytes in patients with autoimmune chronic liver disease.

To study the possible role of T cells bearing the gamma delta T cell receptor (TCR) heterodimer in the pathogenesis of autoimmune chronic active hepatitis (AI-CAH) and primary sclerosing cholangitis (PSC) in children, we measured levels of gamma delta+ T cells in the peripheral blood, assessed the proportion of cells bearing the disulphide-linked (BB3+) and non-disulphide-linked (A13+) subtypes of the receptor, and studied the co-expression of TCR-gamma delta and the activation markers HLA-DR and IL-2 receptor (IL-2R), and the memory cell marker CD45RO. Percentage levels and absolute numbers of gamma delta +T cells were higher in both groups of patients than in controls (P less than 0.01), mainly as a result of an increase in both percentage levels and absolute numbers of the A13+ subtype (P less than 0.001). Co-expression of IL-2R and TCR-gamma delta was not found in controls but was present in some patients with AI-CAH (four out of 17) and PSC (six out of 12) at low levels (median 2.3%, range 1.7-5.0%). Expression of HLA-DR on gamma delta+ T cells was similar in both groups of patients and controls. The majority of gamma delta+ T cells in children with AI-CAH and PSC also expressed CD45RO (74.7 +/- 18.4% and 79.8 +/- 24.3%, respectively) at levels significantly higher than in controls (53.3 +/- 17.2%, P less than 0.01). These results suggest that autoimmune liver diseases in children are associated with an expansion and activation of gamma delta+ T cells in the peripheral blood, which may be important in the pathogenesis of these disorders.     

Serum hepatitis B virus DNA in healthy HBsAg-negative Chinese adults evaluated by polymerase chain reaction

Serum hepatitis B virus (HBV) DNA was assayed using polymerase chain reaction, in 107 HBsAg-negative normal Chinese subjects. The results showed that eight subjects (7.5%) had HBV DNA. In the subgroup with antibody to hepatitis B surface antigen (anti-HBs) and to hepatitis B core antigen (anti-HBc), 7.3% (5/68) were positive for HBV DNA; HBV DNA was not detected in six individuals with anti-HBs only and in nine with anti-HBc only. In four persons with anti-HBc and anti-HBe, one had HBV DNA. In 20 subjects negative for all hepatitis B serological markers, two (10%) were found to have HBV DNA. This study indicates that serological markers are not adequate to rule out HBV infection, and it further implies that present blood donor screening methods may need improving.     

Parental origin of de novo chromosome 9 deletions in del(9p) syndrome

Parental origin of de novo deletions in the short arm of chromosome 9 in patients with a clinical diagnosis of del(9p) syndrome was assessed in 13 patients using polymerase chain reaction (PCR) analysis of highly polymorphic dinucleotide repeat micro-satellite markers located in the putative deleted region. The deletion was found to be of paternal origin in 9 cases and of maternal origin in the remaining 4 cases, suggesting that the molecular event resulting in the deletion occurs in both male and female gametogenesis and that genomic imprinting does not appear to play a role in the patho-genesis of del(9p) syndrome. © 1995 Wiley-Liss, Inc.     

A new, simple and rapid method for enumerating human T lymphocytes in full blood: the E. coli (ATCC 11303) rosette test

A new bacterial rosette technique for enumerating T lymphocytes is described. E. coli (strain B; ATCC 11303), fixed in formaldehyde after overnight growth in thioglycolate medium, are mixed with washed whole blood cells (100 μl) and after incubation at 4°C, slides are made, stained and counted. The nature of the lymphocytes forming E. coli rosettes was demonstrated by comparing their cytochemical staining characteristics with those of E rosetted lymphocytes, and by mixed E. coli and E, mouse E rosette and Fc receptor tests, and by mixed E. coli rosette tests and anti-Ig staining. E. coli and E rosette tests in controls and pediatric patients were also compared. The results show that T_μ and T_γ cells rosette with E. coli.     

Quantitation of hepatitis B viral DNA by solution hybridization: Comparison with DNA polymerase and hepatitis B e antigen during antiviral therapy

Serological markers of hepatitis B virus (HBV) replication were assessed in a randomized, controlled trial of prednisone withdrawal followed by α -interferon in the treatment of chronic hepatitis B. HBV DNA levels in more than 700 serial serum samples from 41 patients were determined by a sensitive and quantitative solution hybridization assay. Results were compared with HBV DNA polymerase (DNAp) activity and hepatitis B e antigen (HBeAg) in 21 untreated controls and 20 treated patients. Among treated patients, the mean pretherapy HBV DNA values were higher in nonresponders than in responders. During prednisone treatment, DNA levels increased an average of 2.1-fold in responders and 1.4-fold in nonresponders. During the 2-week rest interval between prednisone and interferon, DNA values fell an average of 57% in responders. In contrast, the mean DNA values in nonresponders did not change during the same interval. This early distinction between responders and nonresponders was not apparent from DNAp or HBeAg results. During interferon treatment, HBV DNA became undetectable in responders and remained negative during a 1-year follow-up. DNA in nonresponders declined to 14% of baseline during interferon treatment but increased to pretherapy levels after treatment. DNAp values generally paralleled HBV DNA values, but DNAp activity showed more variability and lower sensitivity than did the hybridization assay results. HBeAg values varied independently of HBV DNA and DNAp with a much delayed decline in responders. These results indicate that HBV DNA, when measured quantitatively by a sensitive solution hybridization assay, is an early predictor of the effects of antiviral agents on replication.     

Correlation between soluble serum CD16 (sCD16) levels and disease stage in patients with multiple myeloma

CD16, the type III receptor for IgG, is expressed on neutrophils, natural killer cells, and some T lymphocytes, mast cells, and activated monocytes but not on cells of the B-lymphocyte lineage including plasma cells. It is also produced in a soluble form found in serum. We analyzed sera from 165 multiple-myeloma patients, 29 patients with monoclonal gammopathies of unknown significance, and 20 normal disease-free donors. We found that the level of soluble CD16 was significantly decreased in sera from patients with multiple myeloma compared to sera from healthy and monoclonal gammopathies of unknown significance donors (P=0.0001). In addition, a stage-dependent decrease in soluble CD16 was observed, with a highly significant difference (P=0.004) between stage I and stage II+III myeloma patients. The correlation between the myeloma stage and the serum level of soluble CD16, which is related to the host response, was found to be more sensitive than that of ₂-microglobulin, which reflects the tumor burden. The concomitant evaluation of the serum levels of these two markers allows better staging and therefore has a more precise prognostic value.