The differential effect of pentoxifylline on cytokine production by alveolar macrophages and its clinical implications.

The aim of this study was to investigate the effects of pentoxifylline (PTX) on the production of TNF-alpha, IL-1 beta, IL-6 and GM-CSF by lipopolysaccharide (LPS)-stimulated alveolar macrophages (AM). AM and peripheral blood monocytes (PBM) from 10 patients were cultured for 24 h in the presence of LPS (10 micrograms ml-1) and PTX at concentrations of 2.0 mM, 1.0 mM, 0.5 mM, 0.1 mM and 0.01 mM. TNF-alpha and GM-CSF were measured from the culture supernatants of both the AM and PBM from all 10 patients and IL-1 beta and IL-6 from the culture supernatants of the AM from five patients. The TNF-alpha production by AM was significantly suppressed in the presence of PTX at concentrations of 2.0 and 1.0 mM, while production of IL-1 beta, IL-6 and GM-CSF remained unaffected. In PBM cultures, PTX significantly suppressed the production of TNF-alpha and GM-CSF, at all tested concentrations. The present study provides evidence that PTX selectively suppresses the production of TNF-alpha by LPS-stimulated AM and may have a role in the treatment of lung diseases where TNF-alpha is involved. The mode of administration of PTX should take into account the suppressive effect of this drug on GM-CSF production by PBM.

Prevention of thalassemia.

Prevention of thalassemia and hemoglobinopathies is the only solution to efficiently reduce the huge medical, social and economic impact of these diseases in countries where they occur in high frequencies. In Greece, a serious effort has been undertaken towards this goal over the last years. Prevention is carried out at various levels: ample public education, easy provision of the necessary laboratory tests for carrier identification and thorough counseling of the couples at risk. Availability of prenatal diagnosis has contributed significantly to the acceptance by the public of various screening programmes. To date, the experience of the Greek group for prenatal diagnosis totals 1088 cases (June 1977 to December 1982). The number of couples at risk seeking the test prior to having any children is steadily increasing (prospective counseling). The efficacy of the overall prevention programme in Greece is reflected by the fact that the number of babies with thalassemia major admitted for transfusion to the major Units of the country has decreased substantially in the last years. Routine method used for prenatal diagnosis is biosynthesis of hemoglobin in samples of placental blood drawn by fetoscopy. With increasing experience the procedure now is safe (less than 1% of obstetrical complications in the last year) and the prediction accurate (no false diagnoses in the recent years). However, it is anticipated that the conventional method will soon be replaced by studies of amniotic cell DNA, a procedure both safer and less traumatic, or by studies of trophoblast DNA, which will allow prenatal diagnosis at an earlier stage of pregnancy.

An unusual case of CD4+ CD7+ CD56+ acute leukemia with overlapping features of type 2 dendritic cell (DC2) and myeloid/NK cell precursor acute leukemia.

Type 2 dendritic cell (DC2) acute leukemia has been recently described. We report here an unusual case of a 17-yr-old adolescent with overlapping features of DC2 and myeloid/NK cell precursor acute leukemia as defined by Suzuki et al. The patient presented with lymphadenopathy and hepatosplenomegaly without extranodal manifestations in skin or elsewhere. The morphologic, cytochemical and immunophenotypic features were compatible with those described in DC2 acute leukemia, with co-expression of CD4, CD56 and CD123 antigens. The novel markers BDCA-4 and BDCA-2 considered specific for DC2s were co-expressed. However, bright CD7 positivity along with a dim expression of CD33 (57%) and CD117 (27%) were also noted. Additionally, there was bright expression of NG2 monoclonal antibody 7.1, a frequent finding in myeloid/NK cell precursor acute leukemia. The interpretation of the immunophenotypic profile leads to the hypothesis on the existence of borderline cases between DC2 and myeloid/NK cell precursor acute leukemia. Still, other hypotheses can not be overlooked, such as the possibility for a kind of variant monoblastic leukemia or of another rare entity of acute unclassified leukemia.

Evaluation of methods of pre-vaccination screening for markers of hepatitis B infection.

The prevalence of serologic evidence of hepatitis B virus infection in various populations in Greece was examined to provide data for formulating cost-effective strategies for prevaccination screening. Markers were detected in 17.5% of 320 healthy persons, 73.3% of 273 multiply transfused patients and 61.0% of 146 haemodialysis patients. In multiply transfused patients, antibody to hepatitis B surface antigen (anti-HBs) was significantly more common than antibody to core antigen (anti-HBc) (67.0%, 44.3%), while the opposite was true for haemodialysis patients (43.8%, 57.5%). These data suggest that it may be most cost-effective to screen only for anti-HBs in multiply transfused patients and only anti-HBc in haemodialysis patients. Vaccination without screening may be more cost-effective for healthy persons. Anti-HBs and anti-HBc were detected with similar frequencies (14.7%, 15.9%), thus neither offers an advantage in screening healthy persons, although use of anti-HBc may facilitate detection of chronic carriers. These data indicate that the choice of marker for pre-vaccination screening should depend on the population under consideration.