Експерименти и бъдещето

Основата е използване на DHEA или негови метаболити, сулфатни естери, самостоятелно или в комбинация с друга терапия.
DHEA е естествен андроген, който е интермедиатор по пътя на синтезата на холестерола до тестостерон и който се секретира в големи количества от човешките адреналинови жлези.Около 30 mg/дневно се секретира от адреналиновите жлези под формата на инактивен сулфатен естер и освен това серумните нива на DHEA са пряко свързани в обратна зависимост с нарастването на възрастта.
DHEA, негови метаболити или деривати се приемат от SLE пациенти в нива с такива размери, при които да се увеличат нормалните му нива в кръвта с поне 10 %.Една или повече дози могат да бъдат приемани дневно, за да се достигнат нужните нива в концентрацията.Лечението може да бъде продължително или с прекъсвания.
DHEA може да бъде приеман орално, парентерално или посредством инхалация.Ако се инжектира това може да се направи подкожно, интраперитонеално или интравенозно.В зависимост от начина на прием могат да се формулират дози от 0,5 до 100 тегловни %. Композицията, която обикновено се приема както беше казано има за цел да увеличи нивата на андрогена в кръвта с 10 до 25 %. В общия случай се приемат нива с долна граница 10-25mg и горна граница 250-500mg дневно, за препоръчване 50-250mg като долна и горна граница съответно. Правят се няколко 3-месечни курса на третиране при дневни дози от 250 mg като междувременно се следи общото състояние и се правят лабораторни изследвания на края на всяко тримесечие за да се наблюдава развитието - подобрение, незименение или влошение в наблюдаваните резултати.
Основната цел на приема на DHEA е намаление в нивата на приеманите кортикостероиди и дори тяхното спиране за периоди от време, както и намаление на страничните ефекти от техния прием.

The survival of patients with systemic lupus erythematosus (SLE) has improved tremendously over the past several decades, from a two year survival of 50% in 19391 to five and 10 year survival of 90% and 80% respectively in the 1980s.2 This improvement is attributed mainly to the availability of dialysis, use of corticosteroids and cytotoxic drugs, and improved antibiotics and antihypertensive agents.
However, since the introduction of cytotoxic agents in the treatment of severe SLE, no significant breakthrough in the treatment of lupus patients has been reported. This is probably because the aetiology of the disease is still unknown, and because of the great diversity of the clinical expressions of the disease—which makes it difficult to assess the effect of novel treatments—and the long follow up needed to evaluate changes in prognosis.Moreover, since 80-90% of lupus patients are young women, the use of experimental treatments which might decrease fertility, increase teratogenesis, or have other undesirable side effects is greatly curtailed. Because of these limitations, animal models of SLE could be of considerable value in the evaluation of novel and experimental treatments which that cannot be tested directly on patients. Various animal models of human SLE have been described, which tend to reflect different aspects of the disease. The prototype murine model of spontaneous SLE is the New Zealand black (NZB) mouse,3 principally a model of autoimmune haemolytic anaemia, accompanied by kidney disease and autoantibodies against erythrocytes, ssDNA and dsDNA. A hybrid strain derived from the NZB mouse is one produced by mating this strain with the New Zealand white mouse, the offspring being known as (NZB´NZW)F1.3 The MRL/lpr mouse strain is a model for an accelerated membranoproliferative glomerulo-nephritis associated with anti-DNA production.4 Additional clinical features include lymphoproliferation, synovitis, and vasculitis. Another mouse model for SLE is the B´SB mouse, which is unusual in that the male develops autoimmunity earlier and in a more severe way than the female. Graft versus host disease (GVHD) is produced in mice by injecting lymphocytes from a parent into an F1 hybrid differing at one MHC locus from that parent.5 Several IgG autoantibodies are made, including anti-dsDNA and anti-histones, and fatal lupus-like nephritis mediated by IgG anti- DNA occurs.
Most of the animal models for SLE described so far—except for GVHD—are genetically determined; hence the ability to manipulate the natural history of the disease or to examine the effect of treatments in different stages of the disease is limited. A few years ago, we introduced a novel method for induction of
experimental autoimmune conditions,6–9 including SLE, involving idiotypic immunisation in naive mice. This method is based on Jerne’s theory,10 11 in which the idiotypic determinant of each autoantibody is complemented by those of another, creating an idiotypic network through which immunoglobulin expression might be controlled. This is manifested by the generation of anti-idiotypic antibodies (Ab) of two functional subsets: those that recognise determinants in the V region and do not involve the combining site for the elicit antigen, and those that represent internal images of the elicit antigen (fig 1). We found that immunisation of naive mice in the footpads with a specific autoantibody (for example, anti-dsDNA, anti-cardiolipin, or anti-proteinase-3 antibodies) emulsified in Freund’s adjuvant, followed by a boost injection three weeks later, led to the generation of Ab2, namely an antiautoantibody, and later to mouse Ab3 (anti-anti-autoantibody), which simulates the original autoantibody (human or mouse origin) (fig 1). This ends with naive mice producing specific pathogenic autoantibodies, followed by the emergence of the full blown serological, immunohistochemical, and clinical manifestations of the respective autoimmune disease. In a series of experiments we and others have shown that immunisation of various strains of mice with monoclonal9 13 or polyclonal14 human12–15 or mouse15 anti-DNA antibody, carrying mainly the pathogenic 16/6 Id, ended in the production of a panoply of SLE related autoantibodies by the mouse (anti-DNA, anti-Sm, anti-Ro, anti-histones), a phenomenon referred by us as “autoantibody spread”.16 The serological markers were associated with typical clinical findings of SLE such as increased erythrocyte sedimentation rate (ESR), leucopenia, thrombocytopenia, proteinuria, alopecia, and paralysis, as well as deposition of the mouse anti-DNA antibodies in the glomeruli of the kidneys, skin, and brain8 9 12–17 (fig 2). The time interval between immunisation with Ab1 and generation of mouse Ab3, and autoimmune manifestations, is probably related to many factors, such as genetic predisposition in certain mice strains, the mode of immunisation, and the pathogenic potential of Ab1. We found that BALB/c mice immunised with pathogenic anti-DNA antibodies develop mouse Ab3 2-3 months after immunisation, and full autoimmune disease after four to six months.
We postulate that the natural analogy of this experimental model in humans resides in the induction of antibacterial antibodies carrying pathogenic idiotypes. Indeed, we have already reported previously on the presence of increased titres of the 16/6 Id in the sera of patients infected with mycobacteria (pulmonary tuberculosis)18 and klebsiella (pneumonia and urinary tract infections) or other Gram negative bacteria.19 Thus it is conceivable that infection may trigger autoimmune diseases by inducing antibacterial antibodies carrying the pathogenic idiotypes of autoantibodies (Ab1). In the presence of adjuvant effect (or superantigen?) attributed to the various bacteria themselves, these antibodies may start—in a subject with the “proper” histocompatibility antigens and hormonal background—the cascade of idiotypic dysregulation shown by us in the experimental models, leading eventually to the generation of Ab3 (autoantibody spread), which, either by itself or through regulation, may lead to the overt clinical autoimmune condition. Employing this model, we and others have tested the efficacy of several modes of treatments, in different stages of the disease. In this review we summarise the experience with those treatments, with their potential implications to patients with SLE.
Hormonal manipulations
The strongest risk factor for the development of SLE is female gender. It was felt, therefore, that study of sex related factors would offer a clue to the pathogenesis and treatment of SLE. Studies in the NZB/W F1 murine model for SLE supported a role for female hormones in the modulation of autoantibody production and development of renal disease and death.20 Human studies for the effect of sex hormones in SLE patients are limited, and the results have been conflicting.21 22 We studied the effect of sex hormones upon the induction of experimental SLE in BALB/c female and male mice which underwent orchiectomy.23 It was found that injection of the pathogenic idiotype to females, and to orchiectomised male mice, caused a rapid outburst of the disease compared to non-oestrogen-treated mice. Testosterone treated mice developed the usual response to the human anti-DNA antibody, but failed to develop fulminant SLE-like disease. In another study, the effect of tamoxifen, a synthetic non-steroidal antioestrogen compound, on the development and course of the disease in lupus mice was examined. 24 Although tamoxifen treatment had no effect on the 16/6 Id induced antibody production, it cured the clinical manifestations of the disease. It is noteworthy that delayed tamoxifen treatment also had beneficial therapeutic effects, although it was not as effective as early treatment.24 The results point to the importance of sex hormones in the pathogenesis of SLE, and to the possible beneficial effects of androgen or anti-oestrogen treatment in early stages of the disease. During the last years, not much research has been done in developing new hormonal treatments for SLE patients. Treatment of limited number of patients with the androgen metabolite nandrolene resulted in improvement of disease manifestations in women, but men got worse.21 However, in another study this drug was ineffective in SLE patients.22 Until now, only danazol—an attenuated male sex hormone— has been shown to be of some value in treating haematological (thrombocytopenia) and skin manifestations of SLE.25 26 We believe that our results might promote further research to establish the potential of hormonal modulation of the disease in lupus patients. Prolactin, as a sex hormone, has been found to affect the immune response and modify the expression of autoimmunity in animals and humans.27 Bromocriptine, a dopamine agonist, suppresses the secretion of prolactin by the pituitary gland and in human and animal studies has been found to have immunoregulatory properties.27 28 Evaluating the effect of bromocriptine treatment on mice with experimental SLE,29 we observed a marked reduction of autoantibody levels accompanied by disappearance of clinical and pathological manifestations of the disease. The effect of bromocriptine seems to be non-specific for SLE, since a similar effect was observed in mice with experimental antiphospholipid syndrome (APS).29 Those results were supported by in vitro non-specific effect of CD8 cells, induced in vivo by bromocriptine, on specific lymph node cell proliferation in the presence of pathogenic and non-pathogenic autoantibodies.We also found that injection of CD8 cells from bromocriptine treated mice with SLE or APS abolished the development of disease in the SLE and APS models. Our findingssuggest a possible role for bromocriptine in downregulating autoimmune phenomena through induction of natural non-specific CD8 suppressor cells. The effect of bromocriptine treatment in SLE patients has not been tested in controlled trials, but a few published case reports imply a beneficial effect.30 Recently, it has been reported that SLE patients treated with bromocriptine for six to nine months had a significant decrease in disease activity, associated with lower titres of anti-dsDNA antibodies.31 Our results are in line with those reports, and may suggest a clinical application of bromocriptine treatment in SLE patients.




HUMAN IMMUNOGLOBULIN GIVEN
INTRAVENOUSLY
Normal human immunoglobulin given intravenously (IVIG) has been reported to be effective in treating several autoimmune diseases.50 Several recently published case reports imply that IVIG may have beneficial effect upon various expressions of SLE.51–54 The advantages of IVIG treatment are considerable because of to its infrequent side effects and lack of immunosuppression. The precise mechanism of action of IVIG in autoimmunity is not yet clear, but much of its immunomodulation is attributed to manipulation of the idiotypic network.50 We evaluated the effect of IVIG treatment on immunological and clinical findings in mice with experimental SLE55 which were treated with IVIG (whole molecule, F(ab)2 or Fc fragments). SLE mice, treated with IVIG or its F(ab)2 fragments—but not the Fc fragment— had a complete clinical, serological, and pathological remission which lasted as long as the treatment was given. Inhibition studies pointed to the presence of anti-idiotypic activity to anti-dsDNA antibodies in the IVIG preparation. 55 This implies that the therapeutic effect of the IVIG treatment in our model might be mediated through manipulation of the idiotypic network and neutralisation of pathogenic autoantibodies. The findings are in line with previous studies that show the presence of anti-idiotypic activity in IVIG preparations to several autoantibodies associated with autoimmune diseases.56–58 This may raise the possibility of analysing patients’ serum with the specific IVIG batch before treatment, in analogy to bacterial sensitivities to various antibiotics. Our results further strengthen the role of IVIG treatment in SLE, and may promote the handling of controlled clinical trials in this expensive, yet apparently effective, treatment.



Summary
In this article we have presented our experiences and those of others with various experimental and novel treatments in an experimental model of murine SLE, inducedby immunisation with pathogenic anti-DNA antibody (fig 4). Many of the treatments (summarised in the table) were highly effective in ameliorating clinical, serological, and histological manifestations of the disease. According to our results, it seems that hormonal treatments—such as testosterone metabolites, anti-oestrogens, or bromocriptine—as well as immunomodulation with IVIG or anti-CD4 antibodies, hold the most promising potential for application in lupus patients. We believe, therefore, that these types of treatment should receive high priority in human trials. It should be emphasised, however, that the timing of treatment may be critical, since several treatments were effective when used before or during the induction of the disease. This limitation may pose difficulty for human application, since the aetiology of SLE is still obscure and is probably multifactorial38; therefore it is not yet possible to identify patients at risk of developing SLE. Nevertheless, those treatments which proved to be effective might be used early in the course of the disease in lupus patients and hence influence the outcome of the disease, or may even induce partial or complete remission.