Detection of antibodies to gangliosides and glycolipids in various intravenous immunoglobulin (IVIg) preparations

Intravenous immunoglobulin-based immunotherapy: an arsenal of possibilities for patients and science

The use of intravenous immunoglobulin (IVIG) concentrated from pooled healthy donors' plasma has gained increasing popularity. IVIG therapy has become important as a replacement therapy in primary and acquired humoral immunodeficiencies, and it has been extended to autoimmune, neurodegenerative and inflammatory conditions and transplantation therapy. Recurrent pregnancy failure and cancer are rather new platforms, where IVIG has shown its beneficial effects. This manuscript is focused on these two off-labelled usages. The immunomodulatory mechanisms of IVIG therapy appear as a coordinated orchestration of different functions, resulting in a synergistic effect. Treatment monitoring and detailed molecular analyses reveal how such treatments may interfere with disease pathogenesis. These finding may foster the development of novel therapeutic and/or preventive strategies. Studying this field with bidirectional bench-to-bedside and bedside-to-bench approaches fit well into 'the two-way road' paradigm of translational medicine.

Efficacy of intravenous immunoglobulin (IVIG) affinity-purified anti-desmoglein anti-idiotypic antibodies in the treatment of an experimental model of pemphigus vulgaris

Pemphigus vulgaris is a rare life-threatening autoimmune bullous disease caused by immunoglobulin G (IgG) autoantibodies directed against desmogleins 1 and 3. Previously, we showed that intravenous immunoglobulin (IVIG) ameliorates anti-desmoglein-induced experimental pemphigus vulgaris in newborn naive mice. The aim of this study was to examine the efficacy of anti-anti-desmoglein-specific IVIG in a similar model. Pemphigus-vulgaris-specific IVIG (PV-sIVIG) was affinity-purified from IVIG on a column of single-chain variable fragment (scFv) anti-desmogleins 1 and 3. The anti-idiotypic activity of PV-sIVIG was confirmed by enzyme-linked immunosorbent assay, inhibition assay. After induction of pemphigus by injection of anti-desmogleins 1 and 3 scFv to newborn mice, the animals were treated with PV-sIVIG, IVIG (low or high dose) or IgG from a healthy donor (n = 10 each). The skin was examined 24-48 h later, and samples of affected areas were analysed by histology and immunofluorescence. In vitro study showed that PV-sIVIG significantly inhibited anti-desmogleins 1 and 3 scFv binding to recombinant desmoglein-3 in a dose-dependent manner. Specificity was confirmed by inhibition assay. In vivo analysis revealed cutaneous lesions of pemphigus vulgaris in mice injected with normal IgG (nine of 10 mice) or low-dose IVIG (nine of 10 mice), but not in mice treated with PV-sIVIG (none of 10) or high-dose IVIG (none of 10). On immunopathological study, PV-sIVIG and regular IVIG prevented the formation of acantholysis and deposition of IgG in intercellular spaces. In conclusion, the PV-sIVIG preparation is more effective than native IVIG in inhibiting anti-desmoglein-induced pemphigus vulgaris in mice and might serve as a future therapy in patients with the clinical disease.

Protective effect of intravenous immunoglobulin (IVIG) in an experimental model of pemphigus vulgaris

Uncontrolled studies have found intravenous immunoglobulin (IVIG) to be effective in the treatment of pemphigus vulgaris (PV). The aim of this study was to evaluate the role of IVIG in preventing IgG autoantibodies binding to desmoglein-3 and blister formation using a controlled experimental design. The ability of IVIG to affect the binding of IgG affinity purified from two patients with PV to desmoglein-3 in comparison to IgG from one donor, was conducted by enzyme-linked immunosorbent assay (ELISA). The specificity was confirmed by competition assay. We assessed the effect of IVIG on the induction of experimental-PV in CD1 newborn mice by subcutaneous subjection of IgG affinity purified from two patients with PV. The treatment was conducted by subcutaneous administration of IVIG together with IgG from the pemphigus patients or appropriate control. The skin of the newborns was examined 24-48 h later for blisters, and samples of the affected areas were analysed by immunohistochemistry. IVIG as a whole molecule and its F(ab)(2) portion inhibited the binding of anti-desmoglein-3 antibody to recombinant desmoglein-3 in a dose-dependent manner. The specificity was confirmed by competition assays. In-vivo, IVIG and its F(ab)(2) portion prevented blister formation in the newborn mice. Cutaneous lesions were noted only in the groups of newborn mice who were injected with IgG fractions from the PV patients. Immunopathological evaluation revealed that IVIG prevented the formation of acanthylosis with IgG deposition in the intercellular spaces. These results point to the efficacy of IVIG in the prevention of blister formation in an experimental PV model.

Immunomodulatory Effects of Intravenous Immunoglobulins as a Treatment for Autoimmune Diseases, Cancer, and Recurrent Pregnancy Loss

Intravenous immunoglobulin (IVIG) is a safe preparation, made of human plasma of thousands of healthy donors. The fascinating history of gamma globulin therapy begins in 1930 when Finland treated pneumococcal pneumonia patients with equine serum, which prolonged their survival from pneumonia. Since then, significant breakthroughs were achieved by Cohn, Bruton, Imbach, and others, whose clinical contribution to the world of medicine was of great importance. Originally IVIG was used to treat immunodeficiencies. Later on the use of IVIG extended to autoimmune diseases as well. The efficacy of IVIG has been established only in several autoimmune diseases; clinical reports of trials, series, and case reports indicate significant improvement in many more autoimmune diseases. IVIG have also showed antimetastatic effects in a variety of cancer cell lines, as well as in a few case reports. The efficiency of IVIG has also been observed in recurrent pregnancy loss (RPL), either as a result of an autoimmune disease or spontaneous. Several attempts were made to discover the immunomodulatory effects of IVIG, but it is still not fully understood. Clearly IVIG has multiple mechanisms of actions, which are thought to cooperate synergistically. One of the main mechanisms of actions of IVIG is its ability to neutralize pathogenic autoantibodies via anti-idiotypic antibodies within IVIG preparation. The ability of IVIG to neutralize pathogenic autoantibodies is of great importance in many autoimmune diseases, as well as in RPL. In cancer cell lines, IVIG modulates the immune system in a few ways, including the induction of IL-12 secretion, which consequently activates natural killer cells, and the induction of expression of proapoptotic genes only in cancer cells. Side effects from IVIG are rare and mostly mild and transient. More importantly adverse effects can be minimized by administration to a selective patient population in a proper way: slow infusion rate of 0.4 g/Kg body weight IVIG for 5 consecutive days, given in monthly cycles. The only downside of IVIG therapy is its high price. Therefore, clinicians should balance efficiency versus cost in deciding whether or not to treat certain conditions with IVIG.

Intravenous immunoglobulins neutralize blocking antibodies in Guillain-Barré syndrome

Intravenous immunoglobulin (IVIg) treatment ameliorates the course of Guillain-Barré syndrome (GBS), but its specific mode of action is unknown. We attempted to delineate the effect of IVIg on neuromuscular blocking antibodies in GBS. A total of seven GBS serum samples were examined for blocking antibodies and the effect of IVIg with a macro-patch-clamp technique in mouse hemidiaphragms. First, serum was tested before and after treatment with IVIg. Second, we investigated with coincubation experiments whether the IVIg was capable of neutralizing neuromuscular blocking antibodies in GBS serum or affinity-purified immunoglobulin G (IgG) fractions. Finally, the mechanism of the neutralizing effect was studied by the coincubation of active blocking GBS IgG with Fab and Fc fragments prepared from IVIg. All GBS sera (two adults and two children) and GBS IgG fractions (three adults) taken before treatment with IVIg blocked evoked quantal release by approximately 90%. Blocking activity was markedly reduced in sera obtained after treatment with IVIg. Coincubation of the pretreatment blocking serum with the posttreatment serum, or with the IVIg preparation used for treatment, reduced the blocking activity of the pretreatment GBS serum. When GBS IgG was coincubated with IVIg, the blocking activity of GBS IgG was diminished dose-dependently. Monovalent and divalent Fab fragments prepared from the IVIg were as effective as whole IVIg, but Fc fragments were ineffective. Therapeutic IVIg is capable of neutralizing neuromuscular blocking antibodies in GBS by a dose-dependent, antibody-mediated mechanism. This may, in part, explain its therapeutic efficacy.

Human antibodies accelerate the rate of remyelination following lysolecithin-induced demyelination in mice

Immunoglobulin-based therapies are becoming increasingly common for the treatment of neurologic and autoimmune diseases in humans. In this study, we demonstrate that systemic administration of either polyclonal human immunoglobulins or specific human monoclonal antibodies can accelerate the rate of CNS remyelination following toxin-induced demyelination. Injection of lysolecithin directly into the spinal cord results in focal demyelinated lesions. In contrast to other murine models of demyelinating disease, the mechanism of demyelination following lysolecithin injection is independent of immune system activation, and chronic inflammation at the site of the lesion is minimal. Administration of polyclonal human IgM (pHIgM) or a serum-derived human monoclonal antibody (sHIgM22) resulted in approximately a twofold increase in remyelinating axons when compared to animals treated with saline or with antibodies that do not promote repair. Both pHIgM and sHIgM22 show strong binding to CNS white matter and oligodendrocytes, while antibodies that did not accelerate remyelination do not. This differential staining pattern suggests that enhanced remyelination may result from direct stimulation of oligodendrocyte remyelination by binding to surface receptors on oligodendrocytes or glial progenitor cells. We propose the use of human polyclonal IgM or specific human monoclonal IgM antibodies as potential therapies to enhance myelin repair following CNS injury and disease.