Autoantibodies in outbred Swiss Webster mice following exposure to gold and mercury.

Exposure to heavy metals may have toxic effects on several human organs causing morbidity and mortality. Metals may trigger or exacerbate autoimmunity in humans. Inbred mouse strains with certain H-2 haplotypes are susceptible to xenobiotic-induced autoimmunity; and their immune response to metals such as mercury, gold, and silver have been explored. Serum antinuclear antibodies (ANA), polyclonal B-cell activation, hypergammaglobulinemia and tissue immune complex deposition are the main features of metal-induced autoimmunity in inbred mice. However, inbred mouse strains do not represent the genetic heterogeneity in humans. In this study, outbred Swiss Webster (SW) mice exposed to gold or mercury salts showed immune and autoimmune responses. Intramuscular injection of 22.5 mg/kg.bw aurothiomalate (AuTM) induced IgG ANA in SW mice starting after 5 weeks that persisted until week 15 although with a lower intensity. This was accompanied by elevated serum levels of total IgG antibodies against chromatin and total histones. Exposure to gold led to development of serum IgG autoantibodies corresponding to H1 and H2A histones, and dsDNA. Both gold and mercury induced polyclonal B-cell activation. Eight mg/L mercuric chloride (HgCl2) in drinking water, caused IgG antinucleolar antibodies (ANoA) after 5 weeks in SW mice accompanied by immune complex deposition in kidneys and spleen. Serum IgG antibodies corresponding to anti-fibrillarin, and anti-PM/Scl-100 antibodies, were observed in mercury-exposed SW mice. Gold and mercury trigger systemic autoimmune response in genetically heterogeneous outbred SW mice and suggest them as an appropriate model to study xenobiotic-induced autoimmunity.

Phase I dose escalation study of the PKCι inhibitor aurothiomalate for advanced non-small-cell lung cancer, ovarian cancer, and pancreatic cancer.

Protein kinase C iota (PKCι) is overexpressed in non-small-cell lung cancer, ovarian, and pancreatic cancers, where it plays a critical role in oncogenesis. The gold compound aurothiomalate (ATM) has been shown to inhibit PKCι signaling and exerts potent antitumor activity in preclinical models. We sought to determine the maximum tolerated dose (MTD) of ATM. We conducted a phase I dose escalation trial of ATM in patients with non-small-cell lung cancer, ovarian or pancreatic cancer. Patients received ATM intramuscularly weekly for three cycles (cycle duration 4 weeks) at 25, 50, or 75 mg in a 3+3 design. The dose was not escalated for individual patients. Blood samples were analyzed for elemental gold levels. Patients were evaluated every 4 weeks for toxicity and every 8 weeks for response. Fifteen patients were enrolled in this study. Six patients were treated at 25 mg, seven at 50 mg, and two at 75 mg. There was one dose-limiting toxicity at 25 mg (hypokalemia), one at 50 mg (urinary tract infection), and none at 75 mg. There were three grade 3 hematologic toxicities. The recommended MTD of ATM is 50 mg. Patients received treatment for a median of two cycles (range 1-3). There appeared to be a dose-related accumulation of steady-state plasma concentrations of gold consistent with linear pharmacokinetics. In summary, this phase I study was successful in identifying ATM 50 mg intramuscularly weekly as the MTD. Future clinical investigations targeting PKCι are currently in progress.

Promiscuous interaction between gold-specific T cells and APCs in gold allergy.

Gold compounds clinically used as immunomodulators have high potential to evoke hypersensitivity reactions as an adverse effect. To explore the mechanism of gold allergy, we immunologically characterized T cells infiltrating skin rashes and generated 44 gold-specific T cell clones and lines from a rheumatoid arthritis patient who developed skin rashes and systemic symptoms after gold treatment. CD4(+) and CD8(+) cells predominantly infiltrating the skin rashes and some of the T cell clones and lines shared common Vbetas. These cells exhibited Th0-like, Th2-like, and Tc1-like cytokine profiles, and showed chemotactic activities for thymus and activation-regulated chemokine and IFN-gamma-inducible protein-10 corresponding to the cytokine profiles. T cell recognition of gold consisted of MHC-restricted and MHC-independent pathways. Blocking studies with anti-MHC Abs indicated that the groove of MHC in APCs, where Ags should ordinarily be settled, did not serve as a conjugating site of gold for these T cells in certain cases. These observations raise the possibility that gold-specific CD4(+) and CD8(+) T cells and APCs promiscuously interact under stimulation with gold, resulting in various clinical manifestations in gold allergy.

Targeting oncogenic protein kinase Cι for treatment of mutant KRAS LADC.

Lung cancer is the leading cause of cancer death in the US with ∼124,000 new cases annually, and a 5 y survival rate of ∼16%. Mutant KRAS-driven lung adenocarcinoma (KRAS LADC) is a particularly prevalent and deadly form of lung cancer. Protein kinase Cι (PKCι) is an oncogenic effector of KRAS that activates multiple signaling pathways that stimulate transformed growth and invasion, and maintain a KRAS LADC tumor-initiating cell (TIC) phenotype. PKCι inhibitors used alone and in strategic combination show promise as new therapeutic approaches to treatment of KRAS LADC. These novel drug combinations may improve clinical management of KRAS LADC.

Liposome encapsulated aurothiomalate reduces collagen-induced arthritis in DBA/1J mice.

Collagen-induced arthritis (CIA) generated in rats or mice has long been a model system for the study of rheumatoid arthritis in humans. In particular, this system has been used to study the mechanisms and effects of anti-arthritic drugs in the treatment of the disease. Sodium aurothiomalate (ATM) is an agent often used to treat rheumatoid arthritis in humans; however, it possesses inherent toxicities which limits its usefulness. Liposome-encapsulated drugs are currently being developed to minimize the toxicities associated with a variety of potentially beneficial drugs. We have chosen to encapsulate ATM into small unilamellar vesicles (SUVs) to determine whether greater efficacy would be achieved in treating CIA with SUV ATM as compared to using the free drug. SUVs were prepared from hydrogenated egg phosphatidylcholine and cholesterol. These SUVs were very stable. Vesicles stored at 4 degrees C lost only 0.09% of encapsulated ATM (SUV ATM) after 14 days and were able to reduce collagen-induced arthritis in these mice. Animals treated by i.m. injections of SUV ATM exhibited a 50% reduction in symptoms. More importantly, histological examination of knee joints of the affected animals verified that SUV ATM treatment prevented cellular infiltration of lymphocytes into the synovia of the collagen-sensitized mice. Conditioned media from spleen cell cultures was assayed for the presence of inflammatory lymphokines that might be affected by SUV ATM to account for the success in suppressing collagen-induced arthritis.

The ability of disease modifying antirheumatic drugs to induce and maintain improvement in patients with rheumatoid arthritis. epidemiology of DMARDs treatment in Japan.

OBJECTIVE: The effectiveness of the disease-modifying antirheumatic drugs (DMARDs) methotrexate (MTX), bucillamine (BUC), salazosulphapyridine (SASP) and gold sodium thiomalate (GST) over two courses of treatment with a follow-up period of at least 12 months was evaluated in 425 patients with rheumatoid arthritis. METHODS: Clinical efficacy was evaluated on the basis of the numbers of painful and swollen joints, morning stiffness, grip strength, erythrocyte sedimentation rate, C-reactive protein and rheumatoid factor levels before and after treatment. Results were evaluated on the basis of the survival rate (Kaplan-Meier method) and the incidence and types of adverse drug reactions (ADR) following single and combined therapies. RESULTS: In the first course of treatment, the survival rates for MTX, GST, BUC and SASP were 52.3%, 40.4%, 33.0% and 24.8%, respectively. The rates of development of ADR were 22.9%, 23.5%, 26.3% and 30.0% for BUC, SASP, GST and MTX, respectively. In the second course, the survival rates for MTX, BUC and SASP were 36.6%, 14.1% and 10%, respectively. CONCLUSION: DMARDs used in the first course of treatment improved the clinical parameters until the 6th month after initiation of treatment. Combination treatments showed some effectiveness, but because of the high incidence of ADR the survival rate was low. DMARDs used in the second course of treatment were not efficacious and there was no improvement in the survival rate compared to the first course of treatment.

Clinical pharmacokinetics of oral and injectable gold compounds.

The pharmacokinetics of oral gold (auranofin) in some respects resemble, and in other respects differ from, those of existing parenteral gold compounds such as gold sodium thiomalate (GST). This may in part relate to physicochemical differences as GST is a water-soluble polymeric compound in vitro whereas auranofin is lipid-soluble and characteristically monomeric. Furthermore, intramuscularly administered gold is greater than 95% bioavailable, whereas only 20 to 30% of an orally administered dose of auranofin is absorbed. Following a standard 50mg intramuscular injection of GST, serum gold concentrations rise sharply, peaking between 4 and 8 mg/L in approximately 2 hours and declining to an average of 3 mg/L by 7 days. With repeated injections of GST stable serum concentrations of gold (3 to 5 mg/L) are eventually achieved (usually within 5 to 8 weeks) although absolute concentrations may vary widely between patients. On the other hand, long term treatment with auranofin is associated with lower and more stable serum concentrations of gold (0.5 to 0.7 mg/L), on the standard dosing regimen of 6 mg daily. Both compounds are retained within the body for prolonged periods. However, the amount of gold retained with auranofin is significantly less compared with GST (less than 5% of a tracer dose of auranofin--about 20% of the absorbed dose--is retained by 100 days whereas the retention for a single labelled dose of GST over a similar interval is greater than 50%). Excretory patterns of GST and auranofin also differ. Most of an absorbed dose of GST (greater than 70%) is excreted by the kidneys whereas only 50% of an absorbed (15% of an administered) dose of auranofin is excreted in the urine. Both compounds are avidly bound by plasma proteins and auranofin shows a particularly strong association with circulating cellular elements. In human subjects, parenterally administered gold is widely distributed among bodily tissues, showing a predilection for tissues of the reticuloendothelial system as well as the kidney and adrenal cortex. Comparable studies in humans are not available for auranofin but animal studies have shown comparatively less affinity for the liver, kidney and spleen. Valuable insight has been gained in analysing the comparative pharmacokinetics of oral and injectable gold compounds. Unfortunately, attempts to correlate pharmacokinetic findings with clinical response or pharmacodynamic changes, as a whole, remain largely unsuccessful with these agents.

Optimum Management of juvenile chronic polyarthritis.

The early diagnosis of juvenile chronic polyarthritis rests on the recognition of 3 district modes of onset that are important in preventing deformities, blindness, and even death. Systemic onset is characterised by typical systemic features, including high spiking fever and rheumatoid rash; polyarticular onset is characterised by arthritis of more than 4 joints; and pauciarticular onset by involvement of 4 joints or less, most often a knee initially. Management must be individualised, including the use of non-steroidal anti-inflammatory drugs of which aspirin remains the drug of choice. The course of progressive polyarthritis, found in 15% of children, necessitates the additional use of slow-acting agents, such as intramuscular gold. Supportive measures include rest, splinting and exercise. Regular slit-lamp examination is mandatory to screen for asymptomatic iridocyclitis, which if undetected and untreated may result in blindness.

Induction of stress proteins in mouse peritoneal macrophages by the anti-rheumatic agents gold sodium thiomalate and auranofin.

Gold sodium thiomalate and auranofin, anti-rheumatic gold-containing compounds, induced some stress proteins in cultured mouse peritoneal macrophages. The enhanced synthesis of two proteins, heme oxygenase (a 34-kDa protein) and a 23-kDa protein, was particularly prominent. The 23-kDa protein induced by the gold compounds was identical to that found in macrophages exposed to oxidative stress and was suggested to have antioxidant activity. Intraperitoneal injection of gold sodium thiomalate and oral administration of auranofin to mice induced enhanced synthesis of these proteins in peritoneal macrophages analyzed ex vivo. These data suggest that increased synthesis of these proteins may have a role in mediating the pharmacologic effect of these agents.

Management of pemphigus with gold compounds: a long-term follow-up report.

Fourteen of 15 patients with pemphlgus have responded successfully to systemically administered gold therapy for up to four years. Eight of the 15 (56%) are in remission, requiring no therapy (mean, 21 months). The remaining seven patients are receiving maintenance systemic gold therapy. Only one instance of toxicity was seen during maintenance therapy. The high remission rate associated with gold therapy and the infrequent side-effects during maintenance therapy suggest that systemically given gold therapy may be the treatment of choice for the management of pemphigus, following initial therapy with corticosteroids when necessary.

Characterization of gold in urine and bile following administration of gold sodium thiomalate with chelating agents to rats.

Gold was characterized in the urine and bile of rats treated with D-penicillamine (D-PEN), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropane sulphonate (DMPS), or N-(2-mercapto-2-methylpropanoyl)-L-cysteine (bucillamine) immediately after gold sodium thiomalate (AuTM) injection by both gel chromatographic and electrophoretic methods. It is suggested that the gold in the urine and bile after AuTM administration was predominantly bound to high molecular weight compounds. The characterization of gold in the urine after administration of AuTM with D-PEN, DMSA, or DMPS showed that most of the gold was bound to the chelating agents. In the treatment with the chelating agents such as D-PEN and DMPS, the gold was mainly excreted as a gold-chelating agent compound in the bile and a minor portion of the gold was present in the form of a gold-L-cysteine compound and high molecular weight compounds. DMSA treatment showed that a major portion of the gold was bound to high molecular weight compounds in the bile and a minor portion of the gold was present in the forms of gold-DMSA and gold-L-cysteine compounds. The administration of AuTM and bucillamine indicated that the gold was mainly present as a gold-Me-bucillamine compound in the urine and a gold-bucillamine compound in the bile.

Parenteral methotrexate or gold for rheumatoid arthritis: a follow up.

The forty participants in a double blind controlled trial of parenteral methotrexate or gold for RA were followed up two years later. Fifty percent had remained on the original medication, 13/20 on MTX and 7/20 on gold. Only 5 and 3 of them respectively had no active joint swelling. No major differences between the two groups were seen.

No significant effects of sodium aurothiomalate on haem metabolism and mixed function oxygenase activity in patients with rheumatoid arthritis.

OBJECTIVE: Animal studies suggest that gold compounds impair haem synthesis and increase haem degradation and, as a result, reduce activity of the hepatic haemoproteins cytochromes P-450. The aim of this study was to investigate whether intramuscular gold exerts similar effects in patients with rheumatoid arthritis (RA). METHODS: Urinary porphyrin and precursor excretion, erythrocyte protoporphyrin, and antipyrine clearance, were measured in 6 patients with RA before and 10 weeks after commencement of intramuscular gold. RESULTS: Parameters of haem metabolism were unaffected by gold. While antipyrine clearance was not statistically changed after gold treatment, in 3 of the patients there was an average decrease in antipyrine clearance of 23%. CONCLUSION: Further studies examining RA patients at different time points are required to investigate further the possibility of reduced hepatic drug metabolising activity during prolonged treatment with gold.

Conventional monotherapy compared to a "sawtooth" treatment strategy in the radiographic progression of rheumatoid arthritis over the first eight years.

OBJECTIVE: To describe the treatment with disease-modifying antirheumatic drugs (DMARDs) in two inception cohorts of rheumatoid arthritis (RA) patients and to compare their radiographic outcomes. METHODS: A recent onset RA cohort was collected in Heinola in 1973-1975, and another in Jyväskylä in 1983-1989. The cohorts were followed up prospectively and treated with available DMARDs. The radiographic outcomes of 103 and 85 seropositive cohort patients from Heinola and Jyväskylä respectively were assigned Larsen scores (0-100) for their wrist, hand and foot radiographs in years 0, 1, 3, and 8, and compared with each other. RESULTS: In this study it was seen that DMARD treatment for RA became more extensive over time. The earlier cohort patients were treated with gold sodium thiomalate, chloroquine and D-penicillamine, while 8 additional DMARDs and various DMARD combinations were used for the later cohort patients. At the 8 year visit, 23%, 33%, and 2% of the Heinola patients, and 6%, 45%, and 21% of the Jyväskylä patients respectively were being treated with chloroquine, other single DMARDs, or DMARD combinations. Destruction in the peripheral joints remained lower in the more extensively treated cohort; from 0 to 8 years the median Larsen score increased from 1 to 25.5 and from 0 to 12 (p = 0.001) for the Heinola and the Jyväskylä patients, respectively. CONCLUSION: Our result supports a role of DMARDs in preventing joint destruction in RA in the long-term.

Characterization of protein-bound gold in rat urine following aurothiomalate administration and of rat and human albumin-gold-thiomalate.

The metabolites of gold in the urine of rats given the antiarthritic drug aurothiomalate were investigated by gel permeation chromatography, electrophoresis, and chemical studies. Following a single dose of aurtothiomalate, the excreted gold was protein-bound in the high-molecular-weight (greater than or equal to 150,000 dalton) and serum albumin fractions. Electrophoresis confirmed the presence of albumin, but showed that the other proteins present differ from those in normal or in vitro aurothiomalate-incubated rat sera. The pattern of the proteins establishes that the proteinuria was of the glomerular type. The alterations in the gold distribution produced by incubation of the urine with the low-molecular-weight thiol penicillamine and with exogenously added aurothiomalate indicated the existence of a labile equilibrium of gold among protein binding sites in the urine. Incubation of rat and human sera and commercially prepared serum albumins with aurothiomalate increased the electrophoretic mobility of the albumin. The significance of this change in electrophoretic mobility with respect to two models of gold binding by serum albumin is discussed.

Antiarthritic synergism of combined oral and parenteral chrysotherapy. I. Studies in adjuvant-induced arthritis in rats.

In comparative clinical studies of auranofin (AF, oral gold) and parenteral gold in the treatment of rheumatoid arthritis, no difference in efficacy was detected. Since the pharmacologic profiles of these compounds are different, we studied their combined effect on adjuvant arthritis (AA). The effect of AF alone and combined with gold sodium thiomalate (GTM) or gold sodium thiosulfate (GTS) on the excretion of urinary hydroxyproline (UHP) and urinary calcium (UCa), and the articular index of arthritic rats was followed during five weeks of treatment. The excretion of UHP and UCa was significantly inhibited (P less than 0.005) in rats treated with AF combined with GTM or GTS as compared with animals treated with the individual gold compounds. However, the articular index only decreased significantly (P less than 0.02) in the group of rats treated with AF + GTS. The present studies open the possibility that combined treatment with oral and injectable gold provide a new approach for chrysotherapy with an increased antiarthritic potency.

Antiarthritic synergism of combined oral and parenteral chrysotherapy. II. Increased inhibition of activated leukocyte oxygen burst by combined gold action.

We have observed an antiarthritic effect of combined chrysotherapy in adjuvant arthritis. Since superoxide radicals (O2-) are potent mediators of rheumatoid inflammation, we studied the combined effect of auranofin (AF) and injectable golds on luminol-dependent chemiluminescence (LDCL) and O2- generation by cytochrome-c reduction of activated leukocytes by different receptor-mediated stimuli: phorbol myristic acetate, 10(-6) M; f-Met-Leu-Phe, 10(-6) M; and poly-L-histidine, 10(-5) M. AF, 0.6 and 0.9 micrograms Au/ml, inhibited 34 and 58% of O2- generation, respectively; the addition to AF of 0.3 micrograms Au/ml of gold thiosulfate (GTS) increased this inhibition to 84 and 97% of the oxygen burst. Similar synergistic potentiation inhibition was obtained by LDCL. When the inhibition of O2- generation by the combined action of AF and GTS was compared with AF + gold sodium thiomalate (GTM), only GTS showed an activation on AF's inhibition of the oxygen burst of human leukocytes. The ligand thiosulfate in equimolar concentrations to GTS had a statistically significant (P less than 0.01) inhibitory effect on AF's blockade of O2- generation during the first 5 min of the interaction with the PMNs; thiomalate had no effect. Sequential pretreatment of PMNs with AF and GTS on O2- generation revealed that for synergism of combined gold action to take place, the cell membrane had to be subjected first to the action of oral gold or to the simultaneous combined action of oral and parenteral gold.(ABSTRACT TRUNCATED AT 250 WORDS)

Spread of gold injected into the joints of healthy rabbits.

This study shows that after intra-articular injection, aurothiomalate and colloidal gold of small (200 A) particle size were rapidly absorbed from joints while the larger, 300 A, particle size colloidal radioactive gold could not be found outside them. Larger particle size suspensions seem therefore more likely to remain localised in the joint and its lining synovium after intra-articular injection, the systemic absorption from the joint cavity diminishing with increasing particle size. It was also found that the intra-articular injection of small amounts of aurothiomalate, of colloidal gold and of colloidal radioactive gold produces identical degenerative lesions in the lining cells of the proximal convoluted tubules of the kidneys. These lesions were always found, although gold particles were demonstrated only in sampled kidney tissues of the animals injected with the soluble gold preparation whereas no gold could be detected in the tissues of animals injected with colloidal non-radioactive or radioactive gold. Electron microscopic evidence is presented to suggest the possibility that the mitochondria are the "target" organelles of the gold-induced cellular damage. Mitochondrial damage was demonstrated in liver and spleen in addition to the already described kidney damage. The correlation between structure and function of the mitochondrial changes is not clear, and ionic shifts may be both a cause and a result of damage.

A comparison of prednisolone with azathioprine and prednisolone with intramuscular gold in rheumatoid arthritis.

Pulse prednisolone hemisuccinate therapy (500 mg given intravenously on three occasions over two weeks) has been combined with either intramuscular sodium aurothiomalate or azathioprine in an assessment of 30 patients with rheumatoid arthritis. Significant improvement in a variety of clinical and biochemical assessments was seen in both groups. Both treatments were well tolerated by the patients and prednisolone appeared to accelerate the response to sodium aurothiomalate and azathioprine but there was no great evidence that it enhanced it.