Chrysotherapy. Suppression of immunoglobulin synthesis

Gold-based therapy: From past to present

Despite an abundant literature on gold nanoparticles use for biomedicine, only a few of the gold-based nanodevices are currently tested in clinical trials, and none of them are approved by health agencies. Conversely, ionic gold has been used for decades to treat human rheumatoid arthritis and benefits from 70-y hindsight on medical use. With a view to open up new perspectives in gold nanoparticles research and medical use, we revisit here the literature on therapeutic gold salts. We first summarize the literature on gold salt pharmacokinetics, therapeutic effects, adverse reactions, and the present repurposing of these ancient drugs. Owing to these readings, we evidence the existence of a common metabolism of gold nanoparticles and gold ions and propose to use gold salts as a "shortcut" to assess the long-term effects of gold nanoparticles, such as their fate and toxicity, which remain challenging questions nowadays. Moreover, one of gold salts side effects (i.e., a blue discoloration of the skin exposed to light) leads us to propose a strategy to biosynthesize large gold nanoparticles from gold salts using light irradiation. These hypotheses, which will be further investigated in the near future, open up new avenues in the field of ionic gold and gold nanoparticles-based therapies.

Targeting FcRn for immunomodulation: Benefits, risks, and practical considerations

The neonatal fragment crystallizable (Fc) receptor (FcRn) functions as a recycling mechanism to prevent degradation and extend the half-life of IgG and albumin in the circulation. Several FcRn inhibitors selectively targeting IgG recycling are now moving rapidly toward clinical practice in neurology and hematology. These molecules accelerate the destruction of IgG, reducing pathogenic IgG and IgG immune complexes, with no anticipated effects on IgA, IgM, IgE, complement, plasma cells, B cells, or other cells of the innate or adaptive immune systems. FcRn inhibitors have potential for future use in a much wider variety of antibody-mediated autoimmune diseases. Given the imminent clinical use, potential for broader utility, and novel mechanism of action of FcRn inhibitors, here we review data from 4 main sources: (a) currently available activity, safety, and mechanism-of-action data from clinical trials of FcRn inhibitors; (b) other procedures and treatments that also remove IgG (plasma donation, plasma exchange, immunoadsorption); (c) diseases resulting in loss of IgG; and (d) primary immunodeficiencies with potential mechanistic similarities to those induced by FcRn inhibitors. These data have been evaluated to provide practical considerations for the assessment, monitoring, and reduction of any potential infection risk associated with FcRn inhibition, in addition to highlighting areas for future research.

The genetics of hypogammaglobulinemia

Etiologies for human hypogammaglobulinemias are diverse and include genetic and nongenetic causes. Although recent reviews focus on the complex genetics of common variable immunodeficiency, in this review, we survey different causes of hypogammaglobulinemias and discuss possible mechanisms.

Fatal, gold-induced pneumonitis

We report in detail an experience with irreversible interstitial pneumonitis developed during gold sodium thiomalate therapy. Factors that could influence the unfavourable course of this adverse, usually reversible pharmacological reaction, are analysed, and the importance of early recognition and prompt discontinuation of the drug is emphasised.

Immunosuppressant effect of gold on IgG subclasses and IgE; evidence for sparing of Th2 responses

We set out to examine the effect of gold treatment on the Th2-dependent antibodies IgG4 and IgE in relation to other IgG subclasses in patients with rheumatoid arthritis (RA). Eighty-five gold-treated RA patients and 82 RA controls were studied. Serum IgG subclass concentrations were measured by ELISA, IgE was measured by automated enzyme immunoassay. Samples were studied serially in 13 gold-treated patients and in 11 patients with gold-induced adverse events. There was a significant reduction in the concentration of IgG1, IgG2 and IgG3 in gold-treated RA patients compared with RA controls (P 0.004-0.019), whereas IgG4 was less significantly reduced in gold-treated patients (P = 0.044) and there was no difference in IgE. In serial samples there was a significant fall in the concentration of IgG1 (P = 0.001), IgG2 (P = 0.001) and IgG3 (P = 0.026) with time but no change in IgG4 and IgE. The development of gold-induced adverse events was not associated with any change in the concentration of each IgG subclass or IgE. Deficiencies of IgG subclasses were found in 30% of gold-treated RA patients and 8.5% of RA controls, and were associated in gold-treated patients with a longer disease duration (P = 0.003) and with erosive disease (P = 0. 03). IgG2 was affected most frequently and in the majority of these cases subnormal specific IgG2 binding to widespread polysaccharide antigens (Pneumovax II) was found. Gold induces an overall immunosuppressant effect on IgG subclasses, with a deficiency in 21. 5%, adjusted for controls. The effect on the Th2-dependent antibodies IgG4 and IgE is less marked, suggesting a sparing of Th2 responses.

Synergistic inhibition of human B cell activation by gold sodium thiomalate and auranofin

The mechanism of action of gold compounds, which are effective in the treatment of rheumatoid arthritis (RA), has not been clearly identified. Since one of the characteristic features of RA is chronic stimulation of B cells, the current studies compared the effects of parenteral gold (gold sodium thiomalate; GST) and orally active gold (auranofin; AUR) on human B cells. IgM production was induced from highly purified B cells obtained from healthy donors by stimulation with Staphylococcus aureus Cowan I (SA) plus IL-2. T cell proliferation and IFN-gamma production was induced from highly purified T cells by stimulation with immobilized mAb to CD3. AUR as well as GST suppressed B cell IgM production at much lower concentrations than those that suppressed T cell proliferation or IFN-gamma production. Thus, as little as 0.01 microg/ml AUR (0.015 microM) markedly suppressed IgM production, but neither T cell proliferation nor IFN-gamma production. AUR as well as GST is required at the initiation of cultures to exert optimal suppressive effects on IgM production. Moreover, AUR as well as GST suppressed the expression of CD98 and CD71 on SA-stimulated B cells. Of note, AUR and GST exerted a synergistic inhibitory effect on B cell production of IgM and IgG in a manner which was reversed by catalase, but not by ascorbate. The synergistic inhibitory effect is most likely to be due to thiomalate components of GST, since AUR and thiomalate exerted comparable synergistic inhibitory effects on B cell function. Finally, AUR and bucillamine, another antirheumatic drug with thiol groups, also showed synergistic inhibition of B cell function. These results indicate that AUR and GST preferentially inhibit the function of B cells by interfering with the initial activation of B cells. More importantly, the data indicate that AUR synergizes with GST or thiols to inhibit B cell function in a manner that depends upon the generation of hydrogen peroxide. These synergistic inhibitory effects of AUR and compounds with thiols on in vitro human B cell activation suggest the therapeutic efficacy of combinations of these compounds in RA.

Serum immunoglobulins and the risk of rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with several autoantibodies that can precede the clinical disease. The immunoglobulin concentrations in serum samples before illness were studied to learn more about the immunological process before RA.

METHODS

A case-control study was nested within a Finnish cohort of 19,072 adults who had neither arthritis nor a history of it at the baseline examination during 1973-1977. By late 1989, 124 had developed RA, of which 89 were positive for rheumatoid factor (RF). Three controls per each incident case were individually matched for sex, age, and municipality. The concentrations of IgG, IgA, and IgM were measured from stored serum samples.

RESULTS

Serum IgG before illness was found to be directly proportional to the risk of RF positive RA, and a non-linear association was present between serum IgA and the risk of RF positive RA. These associations were constant between men and women and other subgroups of the study population and not confounded by serum orosomucoid concentration, level of education, smoking, alcohol intake or body mass index. As adjusted for these factors, the odds ratios (95% confidence intervals) of RF positive RA in the lowest, mid, and highest tertiles of IgG distribution were 1.00, 1.55 (0.81, 2.97), and 2.22 (1.16, 4.26), and in the tertiles of IgA 1.00, 2.23 (1.14, 4.36), and 1.78 (0.89, 3.57), respectively. The associations persisted throughout the entire observation period but were most distinct when the period to the onset of clinical RA was > or = 10 years. IgM carried no predictive significance. None of the serum immunoglobulins predicted the development of RF negative RA.

CONCLUSIONS

Increased IgG levels may reflect some, at present unknown process in the early events leading to the development of RA, typically occurring > or = 10 years before the onset of clinical disease.

[Bronchiectasis and rheumatoid arthritis. Incidence and etiopathogenic aspects. Review of the literature]

Many pleural and pulmonary manifestations are described in rheumatoid arthritis, due to the disease itself or drug-induced. A literature review revealed 289 reports of bronchiectasis since 1928, the respiratory symptoms preceding the articular features in 90%. Although the frequency of bronchiectasis in the general population is difficult to assess, and thus maybe underestimated, the prevalence in rheumatoid arthritis seems higher. Thus the recent studies, using modern processes such as high resolution computed tomography of the lungs, assess this association to about 25%. Nevertheless, the methodology of these studies is open to criticism, so the high frequency must be qualified. The pathogenic and aetiological factors remain unknown, and miscellaneous hypotheses, especially immunological, have been suggested. The relationship between both affections can not be asserted, but the association is unlikely to be fortuitous.

Antibody deficiency associated with gold treatment: natural history and management in 22 patients

OBJECTIVE

To perform a clinical and immunological study of patients with rheumatoid arthritis who develop subnormal serum immunoglobulins on gold treatment; to clarify the nature of the defect in antibody production and determine the natural history of this adverse reaction; to use this information to suggest guidelines for the detection, investigation, and management of this complication.

METHODS

22 patients who developed subnormal levels of one or more immunoglobulin isotypes while receiving gold treatment were recruited over a 10 year period from the practice of a single rheumatologist. Antibody production was assessed by measurement of total immunoglobulins and of specific antibody production against polysaccharide and protein antigens, with test immunisation if necessary.

RESULTS

Two broad patterns of antibody deficiency were identified: (1) (n = 11) mild, affecting only one immunoglobulin isotype and with normal specific antibody production. These patients were in general able to continue gold without further deterioration in antibody production. (2) (n = 11) severe, affecting two or three immunoglobulin isotypes, with defective specific antibody production. Six patients developed significant infections and were treated with immunoglobulin. Gold was discontinued in all. Normal antibody production recovered in nine patients, and in all but one followed for more than one year. No relation was seen between duration/dose of gold and antibody deficiency.

CONCLUSIONS

Gold-induced antibody deficiency may be more common than usually recognised. A spectrum of deficiency exists, with some patients developing infective complications. Antibody production should be monitored in patients on gold treatment.

One year treatment with low dose methotrexate in rheumatoid arthritis: effect on class specific rheumatoid factors

We evaluated the effect of a one-year treatment of low dose methotrexate (MTX) on class specific rheumatoid factors in 27 patients with rheumatoid arthritis (RA). Enzyme-linked immunosorbent assay (ELISA) showed after 6 and 12 months a significant reduction of IgM-RF, IgA-RF and IgG-RF levels from the baseline values. During MTX treatment, changes of each RF isotype were not correlated with any other isotype and its corresponding immunoglobulin changes. Moreover, immunological changes were not related to the improvement of clinical parameters. Our results showed that low dose MTX can specifically affect levels of RF isotypes, which are involved in the immune pathogenesis of RA.

Decreased level of antibodies against Helicobacter pylori in patients with rheumatoid arthritis receiving intramuscular gold

BACKGROUND

Sodium aurothiomalate has been reported to have in vitro activity against Helicobacter pylori. Intramuscular gold, as given to patients with rheumatoid arthritis (RA), may therefore influence the colonisation of the gastric mucosa with H pylori.

METHODS

Two groups were compared. One group of 42 patients was treated with intramuscular gold; the other group of 58 patients was treated with antimalarial drugs. Antibodies to H pylori (IgA and IgG) were assessed by an enzyme linked immunosorbent assay (ELISA) and total IgA and IgG were measured by nephelometry.

RESULTS

IgA and IgG antibody titres against H pylori and total IgA and IgG levels were lower in the patients treated with gold than in the group treated with antimalarial drugs. The ratio of IgA antibodies to H pylori to total IgA antibodies and the ratio of IgG antibodies to H pylori to total IgG antibodies were lower in the group treated with gold. The percentage of seropositivity to H pylori was significantly lower in the group treated with gold than in the group treated with antimalarial drugs for the two IgA antibodies (35 and 55% respectively) and IgG antibodies to H pylori (40 and 65% respectively).

CONCLUSIONS

Although this study cannot completely exclude the possibility that a suppressive effect of intramuscular gold on total immunoglobulin production plays a part in the decrease in the titres of IgA antibodies to H pylori and IgG antibodies to H pylori, the lower ratios of antibodies to H pylori to total immunoglobulin antibodies and the lower percentages of seropositivity to H pylori in the group treated with gold suggests that treatment with intramuscular gold decreases H pylori colonisation.

Immunomodulatory effects of therapeutic gold compounds. Gold sodium thiomalate inhibits the activity of T cell protein kinase C

Previous studies have shown that the gold compounds, gold sodium thiomalate (GST) and auranofin (AUR), which are effective in the treatment of rheumatoid arthritis, inhibit functional activities of a variety of cells, but the biochemical basis of their effect is unknown. In the current studies, human T cell proliferation and interleukin 2 production by Jurkat cells were inhibited by GST or AUR at pharmacologically relevant concentrations. Because it has been documented that protein kinase C (PKC) is involved in T cell activation, the capacity of gold compounds to inhibit PKC partially purified from Jurkat cells was assayed in vitro. GST was found to inhibit PKC in a dose-dependent manner, but AUR caused no significant inhibition of PKC at pharmacologically relevant concentrations. The inhibitory effect of GST on PKC was abolished by 2-mercaptoethanol. To investigate the effect of GST on the regulation of PKC in vivo, the levels of PKC activity in Jurkat cells were examined. Cytosolic PKC activity decreased slowly in a concentration- and time-dependent manner as a result of incubation of Jurkat cells with GST. To ascertain whether GST inhibited PKC translocation and down-regulation, PKC activities associated with the membrane and cystosolic fractions were evaluated after phorbol myristate acetate (PMA) stimulation of GST incubated Jurkat cells. Translocation of PKC was markedly inhibited by pretreatment of Jurkat cells with GST for 3 d, but the capacity of PMA to down-regulate PKC activity in Jurkat cells was not altered by GST preincubation. The functional impact of GST-mediated downregulation of PKC in Jurkat cells was examined by analyzing PMA-stimulated phosphorylation of CD3. Although GST preincubated Jurkat cells exhibited an increased density of CD3, PMA-stimulated phosphorylation of the gamma chain of CD3 was markedly inhibited. Specificity for the inhibitory effect of GST on PKC was suggested by the finding that GST did not alter the mitogen-induced increases in inositol trisphosphate levels in Jurkat cells. Finally, the mechanism of the GST-induced inhibition of PKC was examined in detail, using purified PKC subspecies from rat brain. GST inhibited type II PKC more effectively than type III PKC, and also inhibited the enzymatic activity of the isolated catalytic fragment of PKC. The inhibitory effect of GST on PKC activity could not be explained by competition with phospholipid or nonspecific interference with the substrate. These data suggest that the immunomodulatory effects of GST may result from its capacity to inhibit PKC activity.

Panhypogammaglobulinaemia caused by gold therapy

Gold compounds have been successfully used for over 50 years in the treatment of rheumatoid arthritis, but their mechanism of action is unknown. The main disadvantage is the frequent occurrence of side effects which often necessitate discontinuation of therapy. Recently, there have been reports of reduction in immunoglobulin levels in patients on gold treatment; we report a further case of hypoglobulinaemia associated with gold therapy and recommend that immunoglobulins be monitored prior to and during treatment.

The clinical value of measuring immunoglobulins when assessing penicillamine therapy in rheumatoid arthritis

Immunoglobulins are often high in active rheumatoid arthritis and fall when treatment with a slow-acting anti-rheumatic drug is instituted. We assessed the value of monitoring immunoglobulins during penicillamine therapy; 145 patients were followed for up to 5 years, IgA, IgM and IgG levels were compared to 12 other clinical and laboratory variables on 903 occasions. Mean levels of IgA and IgG fell by 10-30%. These changes were less than with ESR or clinical measures such as articular index and duration of morning stiffness. Immunoglobulin levels showed weak correlations with other variables. Only a small number of patients had hypogammaglobulinemia. Initially, 5 cases had low IgA with subsequent falls in 3 more. Initially, 2 cases had low IgG with subsequent falls in 5 more. No patients had low IgM levels. These changes seemed clinically irrelevant. Radiological progression was related to IgA levels. Patients with persistently high rates of radiological progression had persistently higher serum IgA. We conclude that IgM gives the most "acute phase" pattern of response. IgA gives more theoretically interesting information, especially concerning radiological progression. There is only a limited amount of clinically valuable information gained from measuring immunoglobulins.

Expression of CD 21, CD 22, and the mouse erythrocyte receptor on peripheral B lymphocytes in rheumatoid arthritis

The expression of the B cell antigens, CD 21, CD 22, and the mouse erythrocyte receptor (MER), on peripheral mononuclear cells (PMC) in 61 patients with rheumatoid arthritis (RA) and in 25 patients with various other forms of rheumatic disease was studied. Patients with RA showed significantly more peripheral B cells than control patients, whereas there was no difference between patients with RA and controls in resting B cells expressing the MER or resting and activated B cells expressing CD 21. Patients with active RA had significantly less MER positive and more CD 21 positive B cells than patients with inactive disease. The relation between disease activity and expression of MER and CD 21 was independent of drug treatment or production of classical rheumatoid factor. These data may be interpreted as a sign of B cell activation in RA. In addition, patients with seronegative RA receiving gold treatment showed significantly more MER positive cells than patients receiving different drugs, whereas patients receiving non-steroidal anti-inflammatory drugs (NSAIDs) alone had significantly more CD 21 positive cells. This may be the result of different immunomodulating effects of drugs on B cell subsets.

Waaler Rose titres may decrease but increase again during chrysotherapy

In 62 patients with seropositive rheumatoid arthritis, treated with gold compounds, the relationship between serological and clinical response was analysed, based on data on the rheumatoid factor (RF) titre, ESR, number of swollen joints and joint tenderness, through 3 years. Three groups were distinguished. The RF titre became normal in 19, remained elevated in 22, became normal and subsequently again elevated in 21. Responders and non-responders to chrysotherapy occurred in all 3 groups. The findings suggest involvement of pathogenetic mechanisms related to IgM-RF, and of pathogenetic mechanisms which are not related to IgM-RF, and which may be responsive or unresponsive to chrysotherapy.

Gold-induced aplastic anemia

Three patients receiving gold salt treatment for rheumatoid arthritis developed severe aplastic anemia. All three patients experienced remission of their disease at the time of the occurrence of marrow aplasia. Reviewing data on these patients and recent literature indicate that fatal marrow aplasia seems to occur more frequently in sero-negative women who respond well to therapy with gold salts. Frequent blood monitoring in search for any pronounced or sustained drop in red, white or platelet count, even within normal range could serve as a warning sign for myelotoxicity. Despite intensive supportive measures and specific therapeutic attempts, all three patients eventually died of septic shock.

Gold therapy and its indications in dermatology. A review

Gold compounds have long been known as therapeutic agents and have been used extensively in the treatment of rheumatoid arthritis. Their mechanisms of action in vivo, however, remain unclear. In comparison to parenteral gold, the pharmacokinetics of a newly available oral compound, auranofin, differ greatly. Auranofin also appears to have specific immunomodulatory actions and to be associated with fewer and milder toxic effects. The role of chrysotherapy in dermatology has been reemphasized recently. It may be used as an adjuvant in pemphigus or other steroid-responsive diseases to help control disease activity and to taper or eliminate corticosteroid therapy more rapidly. Reports on the use of gold in dermatology are otherwise limited. They include one case of epidermolysis bullosa acquisita and psoriatic arthritis. The benefits of gold treatment have to be weighed against the risks inherent in its adverse reactions, some of which are serious and unpredictable.

Are some major in vivo effects of gold related to microenvironments of decreased selenium?

Gold interacts with selenium in vivo, and the normal distribution of selenium among tissues and subcellular compartments changes. Literature evidence shows that many of the effects of gold compounds on the polymorphonuclear neutrophil, macrophage, and lymphocyte cellular components of the immune system are similar to effects observed in these cellular components in selenium-deficient animals. Affected by these two metals are immune functions related to phagocytic cell migration, phagocytosis, microbial killing, lymphocyte mitogenesis/DNA synthesis, arachidonic acid metabolism/prostaglandin synthesis, and immunoglobulin production. The interaction of gold with selenium in vivo may be responsible for some of the multiparameter-based actions of gold compounds used in the treatment of inflammatory diseases such as rheumatoid arthritis. One mechanism by which gold exerts its clinical effects may be related to its interaction with selenium to produce, in specific microenvironments, decreased levels of this essential trace element.

Effects of gold therapy on the synthesis and quantity of serum and synovial fluid IgM, IgG, and IgA rheumatoid factors in rheumatoid arthritis patients

Eleven patients with active rheumatoid arthritis were monitored prospectively while receiving up to 1 gm of gold sodium thiomalate. There was a significant decrease in serum and synovial fluid IgG, IgA, and IgM rheumatoid factor (RF) levels over the period of study. Comparison of changes in serum RF and total immunoglobulin levels indicated a selective effect on RF production. These observations were supported by changes in the spontaneous in vitro production of IgM-RF and total IgM by peripheral blood mononuclear cells. Studies of synovial membrane synthesis showed a downward trend in immunoglobulin and RF production, but this did not reach statistical significance. A differential effect on the various RF classes was also noted. The most profound effect was on IgM-RF production; whereas, changes in IgG-RF production were least affected. These results suggest a selective and differential effect of gold salts on RF production.

Differential effects of therapeutic regimens on specific classes of rheumatoid factor

This study was performed to define further the relationship of circulating IgM and IgG rheumatoid factor to the articular manifestations of rheumatoid arthritis. Patients with substantial clinical improvement (greater than 55%) or no improvement or worsening were chosen for study. Patients were further selected to include those treated with non-steroidal anti-inflammatory drugs (NSAIDs) alone, or NSAIDs plus D-penicillamine or gold. Significant reductions of IgM (p less than 0.001) and IgG (p less than 0.005) rheumatoid factor were seen only in those treated with gold who improved clinically. These observations suggest that in patients experiencing comparable degrees of clinical improvement the simultaneous alterations of circulating IgG and IgM rheumatoid factor observed are dependent upon the therapeutic regimen employed.

Alterations in macrophage collagenase secretion induced by gold sodium thiomalate

The effects of gold sodium thiomalate (GST) on the production of specific collagenase by thioglycolate-elicited macrophages was investigated. Our studies demonstrated that GST administration can significantly decrease collagenase production in a dose-dependent manner. These effects were observed with levels of GST attainable in serum or synovial tissue during routine chrysotherapy. In addition, GST altered lysozyme secretion by activated macrophages in a pattern distinct from that of collagenase alteration. These effects of enzyme secretion were not secondary effects of GST on viability, general protein secretion, or the specific assay procedures utilized, and were not attributable to the thiomalate moiety. Thus, GST may exert its therapeutic effect in rheumatoid arthritis through interference with the production of degradative proteolytic enzymes, which are important effector molecules mediating tissue destruction.

Therapeutic uses of trace elements

The properties of trace elements which feature in their therapeutic activity are: binding to macromolecules (enzymes, nucleic acids, etc.) with disturbance of biological function, and interaction with other elements. These properties, particularly the binding to large molecules, are far from specific, an observation which is reflected in the very wide range of diseases in which trace elements are employed. While metal compounds have been administered for several centuries, the scientific basis for treatment with trace elements began with the use of gold compounds, initially in patients with tuberculosis and later those with rheumatoid arthritis. Although many other drugs have been developed, some of which also include metal complexes, gold has retained an important position in the treatment of this condition. The gold-induced effects upon the immunological aspects of RA are also observed in other conditions with autoimmune involvement. The antineoplastic potential of metal complexes will be further exploited by the development of less toxic compounds--of platinum and possibly also of other metals. At the same time there are improvements in the protocols for administration which increase the range of cancers responding to treatment. Perturbation of gastrointestinal activity represents another area where trace elements have an important therapeutic role, both in the control of intraluminal acidity and in the adjustment of nutrient availability. A fourth significant area of trace element therapeutics involves the central nervous system where the use of lithium has provided spectacular results in the treatment of affective and other disorders. With a very wide range of other conditions in which they are employed, therapeutic uses provide somewhat unusual illustrations of the importance of trace elements in human disease.

Effect of drug therapy on circulating and synovial fluid Ig-secreting cells in rheumatoid arthritis

A common immunological abnormality in rheumatoid arthritis (RA) is an increased spontaneous polyclonal B cell activation. In order to study the influence of drug therapy in RA on the functional activity of B cells we enumerated spontaneous plaque-forming cells (PFC) in peripheral blood lymphocytes (PBL) and synovial fluid lymphocytes (SFL) by a reverse haemolytic plaque assay. Spontaneous IgG-, IgM-, and IgA-PFC in PBL of 26 patients with classical erosive RA receiving either gold salts or D-penicillamine were similar to those observed in 20 healthy controls. In contrast, significantly higher numbers of IgG- and IgA-PFC, but not IgM-PFC, were found in PBL of nine patients with classical erosive RA receiving non-steroidal anti-inflammatory drugs (NSAID) alone. Furthermore, spontaneous PFC in SFL from 16 consecutive patients with RA receiving second-line drugs, as well as 17 patients with other forms of arthritis (non-RA) were generally low and significantly less than those observed in 20 RA patients on NSAID alone. Moreover, a wide individual variation in PFC, especially in relation to the IgG class, was recorded in the synovial lymphocytes. These studies imply that treatment with second-line drugs is associated with normalisation of B cell activity in RA patients, and that the effect can be detected at the cellular level both in blood and synovial fluid.

Decreased pokeweed mitogen-induced IgM and IgM rheumatoid factor synthesis in rheumatoid arthritis patients treated with gold sodium thiomalate or penicillamine

Prospective and retrospective analysis of data obtained on 119 patients with rheumatoid arthritis suggested a relationship between clinical response induced by gold salts or D-penicillamine and decreased in vitro antibody synthesis by peripheral blood mononuclear cells. A subgroup of 21 patients with inactive disease receiving these drugs was found to have decreased pokeweed mitogen-induced in vitro synthesis of IgM and IgM rheumatoid factor. Detailed analysis of the cellular mechanisms responsible for this decreased responsiveness demonstrated markedly decreased B cell function. Patients treated with D-penicillamine also had altered T cell helper function manifested by incomplete reconstitution of the normal IgM response, while patients treated with gold salts had normal T cell function. Monocytes appeared not to have a major role in the decreased in vitro responsiveness. The results suggest that, in patients who respond to gold salts or D-penicillamine, antibody synthesis by circulating B cells is profoundly decreased, probably due to an indirect effect of these disease-modifying agents.

Hypogammaglobulinaemia associated with gold therapy

Two patients with seronegative arthropathy were noted to be hypogammaglobulinaemic after receiving gold. The clinical course and features suggest that gold is a cause of immunodeficiency.

Drug stomatitis due to gold therapy

Eighteen patients with oral eruptions that developed during chrysotherapy for rheumatoid arthritis were studied retrospectively. The most frequent mucosal changes were nonspecific ulcerations, lichenoid eruptions, atrophy of lingual filiform papillae, and diffuse erythema. Histologic examination generally confirmed the clinical impression. All the eruptions disappeared either spontaneously or after completion of treatment.

Interaction of gold(I) with the active site of selenium-glutathione peroxidase

Gold(I) thioglucose in the presence of excess glutathione (GSH) leads to strong and reversible inhibition of selenium-glutathione peroxidase (EC 1.11.1.9) around neutral pH. Binding at equilibrium and competition studies demonstrated that the most reduced form of the active site selenocysteine is the only binding site for gold(I). Steady-state kinetics that gold(I) forms a dead-end complex with glutathione peroxidase in competition with the reduction of hydroperoxide. The apparent Ki is 2.3 microM at pH 7.6, 37 degrees C and 1 mM GSH. Theoretical models of inhibition were assessed by the use of linear least-squares fitting to a generalized integrated rate equation. The results are consistent with trapping of gold(I) at the active site in the form of a mixed bidentate selenolato -thiolate complex involving GSH and the active site selenocysteine. The kinetics of inhibition imply that the resting form of glutathione peroxidase in the presence of excess GSH is also within the enzyme cycle. This rules out the existence of selenium(+IV) species in the redox cycle of the active site when t- butylhydroperoxide is used as a substrate. Electronic properties of selenium and gold as well as a large relief of inhibition by selenocysteine suggest that a very stable interaction should be obtained between Se(-II) and gold(I) through covalent bonding. These results suggest that glutathione peroxidase could be a target of gold drugs used in the treatment of rheumatoid arthritis.

Inhibition of polyclonally induced immunoglobulin secretion by aurothiomalate

The influence of sodium aurothiomalate on the secretion of immunoglobulins by normal human lymphocytes in vitro was investigated by means of a reverse hemolytic plaque forming cell (PFC) assay. Aurothiomalate inhibited the PFC response induced by pokeweed mitogen (PWM) and by Epstein-Barr virus (EBV) in a dose dependent manner. The inhibition was irreversible, as pre-incubation for 2 h with the drug followed by extensive washing and further culture in gold salt-free medium still caused an inhibition of the PFC response to PWM and to EBV. Cell proliferation was not significantly affected, suggesting that the inhibition of PFC formation was not due to cytotoxicity. Pre-incubation of monocytes/macrophages (Mø's), T lymphocytes and B lymphocytes with the gold compound prior to culture with PWM showed that Mø's and B cells were highly sensitive, whereas T lymphocytes were resistant to the drug. The findings indicate that aurothiomalate inhibits the polyclonally induced PFC response by interfering with accessory Mø function and by affecting the B lymphocyte itself.

Remission-inducing therapy in rheumatoid arthritis

Rheumatoid arthritis is characterized by immunologically mediated chronic inflammation of synovial structures. Remission-inducing drugs, such as gold compounds, antimalarials, and D-penicillamine, have been shown to suppress disease activity in rheumatoid arthritis while having minimal nonspecific anti-inflammatory properties. The possibility that these agents are effective because they modulate the underlying immunologic reactivity prompted an examination of the immunosuppressive properties of these drugs. The evidence indicates that immunosuppression is an action that is shared by these agents and thus supports the view that remission induction may result from suppression of the immunologic activity that underlies rheumatoid inflammation. Despite the fact that these agents can function as immunosuppressives, each appears to have a unique site of action, specifically inhibiting the function of only one of the populations of cells likely to be involved in chronic immunologically mediated inflammation. Gold compounds and anti-malarials appear to be active by virtue of their capacity to depress various functions of mononuclear phagocytes, while D-penicillamine acts by inhibiting a number of the activities of T lymphocytes. These results imply that the means by which these drugs suppress rheumatoid inflammation are fundamentally different. This suggests the conclusion that the remission-inducing drugs may be classified as T cell-active and mononuclear phagocyte-active agents. A better understanding of the pathophysiology of rheumatoid arthritis should thus be helpful in deciding which of these classes of drugs is appropriate in individual cases.

Aplastic anemia in association with gold therapy for rheumatoid arthritis

Over a ten year period five patients developed aplastic anemia in association with gold therapy for rheumatoid arthritis. None of these patients was suitable for bone marrow transplantation due to the lack of a compatible sibling. Four patients with severe aplastic anemia died, despite intensive haemopoietic support and trials of gold chelating agents. Survival ranged from 22 to 103 days (mean 55 days) with death in each case being due to a combination of bleeding and infection. The remaining patient with moderate aplasia survived, recovering over a period of two to three years.

Persistent and transient IgA deficiency in juvenile rheumatoid arthritis

Twenty-five children with serum IgA levels of less than 0.1 g/l (below the 2.5% confidence limit at 2 years of age) were found among approximately 350 cases of juvenile rheumatoid arthritis (JRA). During follow-up, 10 of them proved to have persistent IgA deficiency, 13 were classified as having transient IgA deficiency, and 2 had consistently low serum IgA. Transient IgA deficiency occurred during treatment, in 9 cases with gold and in 2 with antimalarials. The gold-induced IgA deficiency usually developed abruptly soon after institution of gold therapy, and its duration varied from a few months (4 cases) to several years (3 cases). In 6 cases a low IgA level has returned to normal despite continuing gold therapy. In half the patients with persistent IgA deficiency the course has been mild and oligoarticular, and after a mean duration of 8.8 years only one has active disease. In contrast, in the patients with transient IgA deficiency the disease was characterized by early onset (mean age 3.0 years), a polyarticular course (10/13) and prolonged activity (7/13, mean duration 9.6 years). Coeliac disease was diagnosed in 2 patients, both with persistent IgA deficiency.

Clinical responses during gold therapy for rheumatoid arthritis. Changes in synovitis, radiologically detectable erosive lesions, serum proteins, and serologic abnormalities

Gold therapy given to 73 patients with rheumatoid arthritis was associated with remission of synovitis for 3 months or longer in 27 patients and 50% or greater improvement in 20 patients. New joint deformities did not develop in patients who experienced remission, and progression of radiologically detectable erosive changes was prevented. Serum protein and serologic abnormalities were improved in all groups, but patients who had a good response experienced the greatest improvement. No single clinical or laboratory feature in the pretreatment assessment predicted response, but, as a group, the patients with the best response also ranked best for most prognostic indicators.

Mechanisms of action of gold

Since the successful introduction of injectable gold compounds for the treatment of rheumatoid arthritis over 50 years ago, numerous studies on the possible mechanism of action have been performed. This heavy metal has been show to possess a bewildering array of biological effects. Studies using gold performed both in vitro and in vivo can be grouped into anti-microbial, anti-immunologic, anti-inflammatory, anti-enzymatic and other effects. In this survey, we have analyzed these multiple approaches to the study of the mechanism of action of injectable gold preparations and apply the findings to rheumatoid arthritis.

Assessment of immune response during chrysotherapy. Comparison of gold sodium thiomalate vs. auranofin

Auranofin (AF) differs significantly from gold sodium thiomalate (GST) in formulation, i.e., aurous gold is stabilized by dual sulfur and phosphorus ligands, has hydrophobic rather than hydrophilic characteristics, and lacks ionic charge. These attributes facilitate: oral absorption of AF, plasma membrane penetration, increase in intracellular lymphocyte gold concentration and perhaps thereby influence lymphocyte function. AF therapy was observed to affect primarily T rather than B lymphocyte function in 16 RA subjects receiving 6 mg of AF per day for an average of 45 weeks (range 20-74 weeks) compared with GST-treated RA subjects. Lymphocytes from AF-treated subjects manifested prompt and sharp declines in mitogen-induced lymphoproliferative response (LPR); suppressed response to skin testing with dinitrochlorobenzene (DNCB); and blebbing of lymphocyte membranes as shown by scanning electron microscopy. Suppression of LPR with AF was approximately 60% after the first week and 80% after 20 weeks of therapy, contrasting with 0% and 30% for the respective intervals in GST-treated subjects. DNCB skin testing of AF patients, indicated 11 of 14, failed to respond, whereas all GST patients responded. Local or systemic fungal, bacterial and/or opportunistic infections were not encountered. The effect of AF on B cell effector function, e.g., suppression of immunoglobulins and rheumatoid factor titer, was less marked when contrasted with GST therapy in RA subjects, as previously reported.

Metabolic and secretory properties of peripheral and synovial granulocytes in rheumatoid arthritis

The metabolic and secretory properties of peripheral and synovial granulocytes of patients with rheumatoid arthritis were investigated with serum- or immunoglobulin-treated zymosan as activators of cell metabolism. During isolation of the synovial cells precautions were taken to prevent in vitro phagocytosis of immune materials present in the synovial fluids. Oxygen uptake, extracellular release of lysosomal enzymes under resting and activated conditions, yield of the isolated granulocytes, and the granule enzyme content of peripheral and synovial cells did not differ significantly from those of peripheral granulocytes from healthy volunteers. In agreement with the biochemical results, intracellular inclusions could be detected in only a few synovial cells with a direct immunofluorescence technique. The possibility that formation of "ragocytes" may be an in vitro phenomenon is discussed.

Ultrastructural localization and in situ analysis of iron, bismuth, and gold inclusions

The purpose of this article is to review ultrastructural and electron probe X-ray analytical studies on metallic deposits in cells. The metals that will be dealt with are iron, bismuth, and gold, mainly because they have been extensively studied in recent years. The nature and chemical composition of endogenously (e.g., from breakdown of autologous blood) and exogenously (e.g., after a transfusion or injection of iron compounds) produced hemosiderin (i.e., iron deposits) has been the subject of time-hallowed controversies. Quite a few of these have now been resolved by ultrastructural studies and the atomic composition of such deposits has been determined by electron probe X-ray analysis. The interest in bismuth centers around the fact that this is one of the two metals (the other being lead) that produces quite large intranuclear inclusions. Here again much has been learned by ultrastructural and X-ray analytical studies. The interest in gold stems from the fact that soluble salts of this metal are used for the treatment of rheumatoid arthritis and current studies with the above-mentioned techniques indicates how gold produces its beneficial and toxic effects.

Rheumatoid arthritis

Why self-perpetuating joint destruction is intermittent in some patients and unrelenting in others remains largely unknown, but progress has been made in identifying the different types of clinical course and tailoring specific treatment regimens for each.