Development in vitro of human CD4+ thymocytes into functionally mature Th2 cells. Exogenous interleukin-12 is required for priming thymocytes to produce both Th1 cytokines and interleukin-10

Fresh postnatal thymocyte cell suspensions were directly cloned under limiting dilution conditions with either phytohemagglutinin or toxic shock syndrome toxin-1 (TSST-1), a bacterial superantigen. Cultures contained allogenic irradiated feeder cells and interleukin (IL)-2, in the absence or presence of exogenous IL-4, interferon (IFN)-gamma or IL-12. The resulting CD4+ T cell clones generated under these different experimental conditions were then analyzed for their ability to produce IL-2, IL-4, IL-5, IL-10, IFN-gamma and tumor necrosis factor (TNF)-beta in response to stimulation with phorbol 12-myristate 13-acetate (PMA) + anti-CD3 monoclonal antibody or PMA + ionomycin. Different from T cell clones generated from peripheral blood, virtually all CD4+ T cell clones generated from human thymocytes produced high concentrations of IL-2, IL-4 and IL-5, but no IFN-gamma, TNF-beta or IL-10. Moreover, after activation, these clones expressed on their surface membrane both CD30 and CD40 ligand, but not the product of lymphocyte activation gene (LAG)-3, and provided strong helper activity for IgE synthesis by allogeneic B cells. The Th2 cytokine pattern could not be modified by the addition of IFN-gamma. However, upon addition of exogenous IL-12, the resulting CD4+ thymocyte clones produced TNF-beta, IFN-gamma, and IL-10 in addition to IL-4 and IL-5. These results suggest that CD4+ human thymocytes have the potential to develop into cells producing the Th2 cytokines IL-4 and IL-5, whereas the ability to produce both Th1 cytokines and IL-10 is acquired only after priming with IL-12.

Association of responsiveness to the major pollen allergen of Parietaria officinalis with HLA-DRB1* alleles: a multicenter study

Parietaria, a plant belonging to the family of Urticaceae, is a major source of allergenic pollen in Europe. In the context of a multinational study, we investigated whether in allergic subjects antibody response towards Par o 1, the major allergen from P. officinalis, was associated with defined HLA-DRB1* alleles. The study population consisted of 234 allergic patients: 65 from Bulgaria, 30 from Israel, 99 from Italy, and 40 from Spain. In the Italian study group, the prevalence of ST positivity to Parietaria was 77%. In Parietaria ST-positive subjects, the prevalences of IgG and IgE serum Ab towards Par o 1 were 91% and 75%, respectively. HLA-DRB1*1101 and/or 1104 were significantly positively associated with the presence of IgG Ab and with high levels of IgE Ab towards this allergen (p = 0.0007 and p = 0.012, respectively). In the Spanish study group, the positive association of DR1100 with responsiveness to Par o 1 was confirmed (p = 0.02, RR = 4, and p = 0.002, RR = 7, for IgG and IgE Ab, respectively). None of the Bulgarian patients had IgE Ab to Par o 1, whereas IgG Ab response was observed in 7 out of 65 subjects and was positively associated with DRB1*1101 and/or 1104 (p = 0.025). In the Israeli study group, responsiveness to Par o 1 was not associated with specific HLA-DRB1* alleles. In conclusion, this study shows that in allergic patients from three European populations antibody response to the major allergen from the pollen of Parietaria is associated with HLA-DRB1*1101 and/or 1104. Our data suggest that this association is stronger in subjects monosensitized to Parietaria.

Protective effects of carvedilol, a vasodilating beta-adrenoceptor blocker, against in vivo low density lipoprotein oxidation in essential hypertension

Low density lipoprotein (LDL) oxidation plays a crucial role in the development and progression of atherosclerosis and is enhanced in patients with essential hypertension. This finding has stimulated a search for antihypertensive drugs with high intrinsic antioxidant properties. We investigated the antihypertensive and antioxidant effects of carvedilol, a new vasodilating beta-adrenoceptor blocking agent in a group of patients with mild to moderate essential hypertension after 4-month treatment. Carvedilol administration markedly increased the resistance to oxidation of LDL isolated from treated patients to values comparable to those of control, nonhypertensive subjects. This effect was achieved despite a significant loss in LDL-associated vitamin E. The increased resistance of LDL to oxidation promoted by carvedilol was not related to the normalization of previously increased blood pressure (BP). Indeed, the administration of other conventional antihypertensive drugs, capable of decreasing arterial BP but without high intrinsic antioxidant properties, to a control group of matched hypertensive patients failed to ameliorate LDL oxidation parameters. Carvedilol treatment also reduced the extent of in vivo LDL oxidation, as reflected by the decrease in antioxidized LDL autoantibody titer. This effect as well was detected only in the group of carvedilol-treated hypertensive patients and not after the simple reduction in BP obtained with antihypertensive drugs different from carvedilol.

Effects of interferon-alpha on cytokine profile, T cell receptor repertoire and peptide reactivity of human allergen-specific T cells

A large panel of T cell clones (TCC) specific for the recombinant form of Poa pratensis allergen (rKBG7.2 or Poa p9) were established from the peripheral blood of grass pollen-sensitive donor in the absence or presence of recombinant interferon-alpha (IFN-alpha) in bulk culture and their pattern of cytokine secretion, peptide reactivity and TCR V beta repertoire was examined. The majority of allergen-specific TCC derived in absence of IFN-alpha produced high amounts of interleukin-4 (IL-4) and IL-5 but not IFN-gamma (Th2 cells), while most of TCC derived in presence of IFN-alpha produced IFN-gamma but not, or limited amounts of, IL-4 and IL-5 (Th1 or Th0 cells). Of 24 TCC established in the presence of IFN-alpha, 22 were able to recognize a single allergen peptide, p26, while none of the clones established in the absence of IFN-alpha showed a similar specificity. The majority of both clones expressed the V beta 2 element regardless of whether they were established in the presence of INF-alpha, but the presence of IFN-alpha favored the expansion of V beta 2+, V beta 17+ and V beta 22+ Poa p9-specific T cells, whereas in the absence of IFN-alpha, other TCR V beta-bearing T cells (V beta 5, and V beta 6.7, and V beta 14) were expanded in addition to V beta 2+ T cells. None of V beta 2+ clones established in the absence of IFN-alpha reacted with p26, whereas all the V beta 2+ clones established in its presence in the absence of interferon-alpha reacted with p26, whereas all the V beta 2+ clones established in its presence reacted to this peptide. IFN-alpha also shifted the TCR V beta repertoire of both Poa p9- and Lolium perenne group 1 (Lol p1)-specific T cell lines generated from the same patient and from a different grass-sensitive individual. These data demonstrate that IFN-alpha modulates the development of allergen-specific T cells in vitro, and suggest that IFN-alpha may represent a useful tool for novel immunotherapeutic approaches in allergic disorders.

[The procedures and results of a quality control program in mammography carried out on a regional basis]

In 1990 the region of Tuscany instituted a quality control program for mammography, in order to check the working conditions of mammography centers in the region, to investigate the feasibility of applying some working standards in line with European recommendations, and to promote the training of personnel. The program involves the following: a test of newly acquired mammographic equipment to establish that it meets the required standards; an annual test of generators, X-ray beams, grid, AEC, screen-film system, film processing, dose and image quality; daily test (phantom radiography and film sensitometry) performed by the personnel of each mammographic Unit; and a sustained advisory service for the technical problems occurring between checks. Thirty-nine of 57 centers participated on a voluntary basis, and 135 checks were performed annually. The results of the program show a performance below the recommended standard in relation to AEC, film sensitometry and the adequacy of lights in dark rooms in 40%, 50% and 63%, respectively, of the centers. Entrance exposure was over 1500 mR, with a maximum value of 3450 mR, in 6 cases in the first round. 5 cases in second, and only 1 case in the third. In general, the results are slightly improving, but mammography optimization is still a long way off. It is necessary to carry out suitable programs for quality control in mammography on a regional basis and to establish precise guidelines for individual mammographic Units to follow in order to meet the European standards.

Antenatal sonographic diagnosis of clubfoot: a six-year experience

In the period 1988 through 1993, 6351 pregnant women were referred to the Department of Obstetrics and Gynaecology, University "La Sapienza", Roma, for suspected fetal anomalies or maternofetal problems. All underwent serial transabdominal and/or transvaginal ultrasound scanning, which revealed a total of 235 fetuses with hydrocephalus, cardiac, or musculoskeletal malformations. Forty-one clubfeet were detected in 27 pregnancies in the early part of the second trimester of pregnancy. Of these, 14 feet in eight patients were isolated, and were classified as idiopathic. A clubfoot was associated with neural tube defects in six patients, with anomalies of the urinary and/or digestive system in a further six, with a cystic hygroma in two, and with other musculoskeletal abnormalities in the other six patients. Amniocentesis revealed an abnormal karyotype in six fetuses (22.2%). In only two cases was oligohydramnios present. In both these patients, a fetal urinary tract malformation was present Polyhydramnios was found in 18 cases, and a normal amount of amniotic fluid was found in the remaining seven cases. Polyhydramnios was present in six of the eight idiopathic clubfoot fetuses. Clubfoot is associated with musculoskeletal and visceral anomalies in a high proportion of cases. The association of clubfoot with polyhydramnios in a high proportion of cases does not support the hypothesis of intrauterine moulding as an etiological factor in its development. Ultrasonographical prenatal detection of a clubfoot should prompt amniocentesis, as the condition is associated with an abnormal karyotype in a significant proportion of cases.

CD30 ligation induces nuclear factor-kappa B activation in human T cell lines

CD30 is a recently described member of the tumor necrosis factor/nerve growth factor receptor superfamily. In this report, we show that following incubation of L540 cells (Hodgkin's disease-derived, T cell-like, CD30+ cells) with the agonistic anti-CD30 monoclonal antibodies (mAb) M44 and M67, two nuclear factor (NF)-kappa B DNA binding activities were induced in nuclear extracts, as determined in gel retardation assays. The effect of the mAb towards NF-kappa B activation was rapid, as it occurred within 20 min, and was sustained for up to 6 h. By comparison, an isotype-matched antibody had no effect on NF-kappa B activation. Moreover, in human T helper (Th) clones functionally characterized as being of the type 0, type 1 and type 2 (28%, < 1% und 93% CD30+, respectively), the extent of CD30-mediated NF-kappa B activation correlated with the proportion of CD30+ cells. In all cell lines investigated, the NF-kappa B complexes induced following CD30 engagement were shown to contain p50 NF-kappa B1, p65 RelA, and possibly other transcription factors. Collectively, our results demonstrate that nuclear translocation and activation of NF-kappa B rank among the short-term cellular responses elicited following CD30 ligation.

No relationship between skin-infiltrating TH2-like cells and allergen-specific IgE response in atopic dermatitis

More than 500 CD4+ T-cell clones (TCCs) derived from the skin of eight patients with atopic dermatitis (AD), two patients with nonatopic dermatologic disorders, two patients with allergic rhinitis, and one healthy nonatopic donor were analyzed for both their pattern of cytokine production and their antigen specificity. The proportions of TCCs from patients with AD producing interleukin-4 in response to stimulation with phorbol 12-myristate 13-acetate plus anti-CD3 antibody were higher, whereas the proportions of interferon-gamma--producing TCCs were lower than those of control subjects. In two patients with AD, the majority of TCCs had a TH2/TH0-like phenotype, whereas in six patients with AD a TH1/TH0-like phenotype was prevalent. TCCs with a TH2/TH0-like phenotype were also isolated from the healthy skin of two patients with allergic rhinitis and one nonatopic donor. In contrast, no TH2-like TCCs were derived from the skin of the two patients with dermatologic disorders of nonallergic origin. No unambiguous correlations was found between the proportions of TCCs producing interleukin-4 or interferon-gamma (or of TCCs with TH2- or TH1-like profile) and the level of total serum IgE, suggesting that CD4+ T cells infiltrating the atopic skin do not play a major role in the production of serum IgE antibodies. When TCCs from five patients with AD were examined for their specificity, the proportions of allergen-specific (Dermatophagoides pteronyssinus and Lol p 1) clones were consistently 6% or lower even in patients with high titers of ryegrassor D. pteronyssinus-specific IgE antibodies. Because similar percentages of allergen-specific TCCs were found in skin from two healthy control subjects, the role of aeroallergens in favoring and maintaining skin lesions in patients with AD remains unclear.

Polyinosinic acid: polycytidylic acid promotes T helper type 1-specific immune responses by stimulating macrophage production of interferon-alpha and interleukin-12

The effects exerted on the development in vitro of Dermatophagoides pteronyssinus group I (Der p I)-specific T cell lines and T cell clones by addition of polyinosinic acid: polycytidylic acid (poly I:C) in lymphocyte bulk culture were examined. Der p I-specific T cell lines generated in presence of poly I:C exhibited reduced ability to produce interleukin (IL)-4 and IL-5 and developed into Der p I-specific CD4+ T cell clones showing a T helper (Th) type 0 or Th1, instead of Th0/Th2 cytokine profile. This effect was prevented by addition to lymphocyte bulk cultures of a mixture of antibodies specific for interferon (IFN)-alpha and IL-12, whereas the addition of anti-IFN-alpha or anti-IL-12 antibody alone was uneffective. Poly I:C also showed the ability to stimulate the production of noticeable amounts of both IFN-alpha and IL-12 by human monocytes. Taken together, these data suggest that poly I:C is a Th1-inducing agent whose activity is mediated by its ability to stimulate the production of IFN-alpha and IL-12 by monocytes.

Activation of HIV expression by CD30 triggering in CD4+ T cells from HIV-infected individuals

CD30 is a member of the tumor necrosis factor receptor superfamily, preferentially expressed by T cells producing type 2 helper (Th2) cytokines, whose ligand (CD30L) has been identified on B cells, activated macrophages, and a subset of activated T cells. We show here that cross-linking CD30 with an agonistic CD30-specific monoclonal antibody, as well as with CD30L+ CD8+ T cell clones or CD30L+ B cells, enhanced HIV replication in CD4+ T cells from HIV-infected individuals, and such a potentiating effect was inhibited by anti-CD30L antibody. The anti-CD30L antibody also exerted a suppressive effect on spontaneous HIV replication occurring in lymph node cells from an HIV-sero-positive patient, showing CD30L expression by both B and CD8+ T lymphocytes. Thus, CD30 triggering by CD30L-expressing cells may plan an important role in the activation of HIV expression from latently infected CD4+ T cells.

Isolation and characterization of allergen-binding cells from normal and allergic donors

BACKGROUND

Flow cytometry of the immune system so far has been limited to the analysis of subpopulations according to lineage markers. The cells involved in a particular immune response could not be assayed due to their low frequency. Here we show the potential of antigen-specific high gradient magnetic cell sorting to enrich cells for visualisation in multiparameter cytometry, functional studies and immortalization.

OBJECTIVES

The aim of this study was the development of an efficient technology for staining and isolation of antigen-binding cells from human peripheral blood. In particular, allergen-specific cells from normal and allergic donors should be analysed and compared to develop a cellular diagnosis of allergy.

STUDY DESIGN

The rare antigen-specific cells were sorted by high-gradient magnetic cell sorting with MACS. Haptenized phospholipase A2 (PLA2), the major allergen of bee venom, or haptenized ParoI, the major allergenic component of Parietaria officinalis, were used as antigens. The cells from normal and allergic donors, binding to the allergen were characterized phenotypically by immuno-fluorescence. Allergen-specific B-cells were immortalized by EBV transformation.

RESULTS AND CONCLUSION

Allergen-specific cells can be enriched from blood of both allergic and normal donors to purities of up to 75%, by high gradient magnetic cell sorting. The specificity of labelling with allergen was confirmed by establishing allergen-specific EBV-transformed B-cell lines from the sorted cells. Clear differences exist in the cellular composition of allergen-binding cells from normal compared to allergic donors. In normal donors the allergen-binding cells are B-cells expressing CD19 and CD21. In allergic donors, in addition to allergen-binding B-cells, occurring in about equal absolute numbers as in normal donors, basophilic granulocytes are labeled by allergen. These cells express CD38, CD9 and CD25 on their surface, and stain for IgE.

CD8+ T lymphocytes producing Th2-type cytokines (Tc2) in HIV-infected individuals

Unusual high proportions of CD8+ T-cell clones able to produce IL-4, but no IFN-gamma (Tc2 cells), were generated from both skin biopsies and peripheral blood of HIV-infected individuals in advanced phase of infection. Tc2 cells showed unusual phenotypic and functional features, such as CD30 expression, B-cell helper activity for IgE synthesis and reduced cytolytic potential. Cloning CD8+ T-cell from HIV-infected individuals in autologous feeder cells resulted in a marked increase of CD8+ T-cell clones showing a Tc2 profile. The addition in bulk culture before cloning of both IL-12 and a neutralizing anti-IL-4 antibody dramatically reversed the cytokine profile of CD8+ T-cell clones of HIV-infected individuals to the classic Tc1 pathway. Finally, cloning CD8+ T-cells from healthy HIV-seronegative donors in the presence of feeder cells from HIV-infected individuals resulted in the development of enhanced proportions of CD8+ T-cell clones able to produce IL-4. These data suggest that CD8+ T-cells from HIV-infected individuals can develop into Tc2 cells likely because of either the defective production of IL-12 by HIV-infected macrophages and/or other microenvironmental conditions favoring early IL-4 production. The Tc2 shift during HIV infection may play some role in the reduced defence against viral infections, including HIV itself, in patients with AIDS.

CD30 and type 2 T helper (Th2) responses

CD30 is one of the members of the tumor necrosis factor receptor superfamily, originally described as a marker of Reed-Sternberg and Hodgkin's cells in Hodgkin's lymphoma. CD30 appears to be preferentially expressed on, and its soluble form (sCD30) released by, CD4+ and CD8+ T cell clones capable of producing T helper 2 (Th2)-type cytokines. In noneoplastic conditions, CD30+ T cells are barely detectable in vivo; however, a few allergen-specific CD4+CD30+ T cells inducible to the production of Th2-type cytokines could be sorted out from the circulation of allergic subjects after allergen exposure. Moreover, high numbers of CD30+ T cells were found in the lymph node of a patient suffering from Omenn's syndrome, a rare congenital Th2-mediated immunodeficiency disorder. More importantly, high serum levels of sCD30 were observed in some conditions in which a pathogenetic role for Th2 cells has been suggested, such as Omenn's syndrome, atopy, systemic lupus erythematosus, and after infection with measles virus or human immunodeficiency virus. Thus, detection of CD30+ T cells and/or of increased levels of sCD30 may reflect the presence of immune responses or immune alterations characterized by the prevalent activation of Th2-like cells.

[Oxidation of low-density lipoproteins. Correlation between reduced resistance in vitro and increased oxidation in vivo]

OBJECTIVES

The oxidation of low-density lipoproteins has been recently proposed as one of the critical factors in promoting atherogenesis. This process results from the balance between the prooxidant stimuli and the endogenous antioxidants present in LDL and strictly depends on the concentration of oxidizable substrates, namely unsaturated fatty acids.

METHODS

Twelve male hypertriglyceridaemic patients were investigated before and after oral supplementation with omega-3 polyunsaturated fatty acids (PUFA) and compared with eighteen untreated healthy matched control subjects. The plasma lipid profile was measured in all patients. LDL oxidation was evaluated as both the susceptibility to in vitro oxidation and the presence of plasma anti-oxidized LDL antibodies (as a marker for in vivo oxidation).

RESULTS

Omega-3-fatty acid supplementation caused a significant reduction in plasma triglyceride level (267 +/- 38 vs 375 +/- 33 mg/dl, p < 0.01) and decreased the resistance of LDL to oxidation as revealed by an early and accelerated generation of conjugated dienes following exposure to CuSO4 (105.3 +/- 7 vs 133 +/- 9.3 min, p < 0.01). Moreover, the concentration of the antioxidant vitamin E in LDL was slightly but significantly decreased at the end of the treatment (2.59 +/- 0.19 vs 2.89 +/- 0.17 nmol/mg LDL, p < 0.05), but its efficiency in preventing LDL oxidation was unaltered. Furthermore, a marked increase of the plasma anti-oxidised LDL antibody titre was found in nearly all patients at the end of the treatment (2.08 +/- 0.48 vs 1.37 +/- 0.2 anti-oxidised/anti-native LDL antibody ratio, p < 0.001).

CONCLUSION

These results indicate that PUFA supplementation decreases the resistance of LDL to in vitro oxidation and that this decreased resistance is accompanied by an enhanced LDL oxidation in vivo.

CD30, Th2 cytokines and HIV infection: a complex and fascinating link

CD30 is a member of the tumor necrosis factor (TNF)/nerve growth factor (NGF) receptor superfamily, and was originally described as a marker of Hodgkin's and Reed-Sternberg cells in Hodgkin's lymphoma. CD30 is preferentially expressed on CD4+ and CD8+ T-cell clones that produce T helper 2 (Th2)-type cytokines, and is also released in a soluble form by these cells. Elevated serum levels of soluble (s)CD30 have been found in some conditions in which a pathogenic role for Th2 cells has been suggested, such as atopy, Omenn's syndrome, systemic lupus erythematosus, as well as following infection with measles virus or human immuno-deficiency virus (HIV). Here, Gianfranco Del Prete and colleagues suggest a complex and fascinating link between the expression and release of CD30, and the immunopathogenesis of HIV infection.

Autoantibodies against oxidatively modified low-density lipoproteins in NIDDM

Diabetes is an independent risk factor in the development of atherosclerosis, although the pathophysiological processes underlying this association are poorly understood. The oxidation of low-density lipoprotein (LDL) is considered a key event in the development and progression of atherosclerosis because it generates molecular epitopes that are more atherogenic than parent LDL. A total of 138 patients suffering from non-insulin-dependent diabetes mellitus (NIDDM) and 80 matched control subjects were investigated. LDL oxidation was evaluated as the presence of autoantibodies against oxidatively modified LDL, since they mirror the in vivo occurrence of oxidative processes. NIDDM patients had an antibody ratio (calculated as the ratio of antibodies against modified versus native LDL) significantly higher than control subjects for Cu(2+)-oxidized LDL (1.88 +/- 0.6 vs. 1.05 +/- 0.3, P < 0.01, for IgG), malondialdehyde-modified LDL (2.54 +/- 0.73 vs. 2.04 +/- 0.11, P < 0.01, for IgG and 3.96 +/- 1.51 vs. 2.90 +/- 0.15, P < 0.01, for IgM), and malondialdehyde-modified human serum albumin (1.79 +/- 0.54 vs. 1.46 +/- 0.1, P < 0.05 for IgG). The possible role played by glycation in sensitizing LDL to oxidation was investigated by measuring autoantibodies against both glycated LDL (glycLDL) and glycoxydated LDL (glycoxLDL). NIDDM patients had an antibody ratio significantly higher than control subjects for anti-glycLDL and anti-glycoxLDL IgG (1.79 +/- 0.38 vs. 1.12 +/- 0.23, P < 0.01 and 2.55 +/- 1.03 vs. 1.39 +/- 0.44, P < 0.01, respectively) but not anti-glycLDL and anti-glycox-LDL IgM.(ABSTRACT TRUNCATED AT 250 WORDS)

Presence of autoantibodies against oxidatively modified low-density lipoprotein in essential hypertension: a biochemical signature of an enhanced in vivo low-density lipoprotein oxidation

OBJECTIVE

We have previously reported that low-density lipoproteins (LDL) isolated from patients with essential hypertension are more susceptible to in vitro oxidation than lipoproteins isolated from normotensive control subjects. In the present study we investigated the occurrence of in vivo LDL oxidation in hypertensive patients.

DESIGN

The presence of antioxidatively modified LDL autoantibodies was taken as a suitable index of in vivo LDL oxidation because, after oxidative modifications, LDL express antigenic epitopes that elicit an immune response. The antibody titres were measured in plasma from untreated patients with newly diagnosed essential hypertension.

METHODS

An enzyme-linked immunosorbent assay method was employed, using native LDL, Cu(2+)-oxidized LDL and malondialdehyde-derivatized LDL (MDA-LDL) as antigens. Human serum albumin and MDA human serum albumin were also used to monitor cross-reactivity with other oxidized molecules. The antibody titre was expressed as the ratio between anti-modified and anti-native antigen absolute values.

RESULTS

The patients with essential hypertension had an antibody ratio significantly higher than control subjects with respect to anti-Cu(2+)-oxidized LDL immunoglobulins G and M, and with respect to anti-MDA-LDL immunoglobulins G and M. A significant positive correlation was found between anti-MDA-LDL and anti-Cu(2+)-oxidized LDL antibody titres. The anti-MDA human serum albumin antibody titre was not different in the two groups of patients. An inverse correlation was detected between the anti-MDA-LDL immunoglobulin M titre and the age of the patients.

CONCLUSIONS

The results obtained are consistent with the view that, during the early phases of hypertension development, LDL undergo in vivo oxidation that is mirrored by the generation of autoantibodies against epitopes of oxidized LDL. The oxidation process appears specific for LDL and might be relevant both for the progression of hypertension and for the development of the atherosclerosis that often complicates hypertension itself.