Gout: a review of its aetiology and treatment

OBJECTIVE

To review the current understanding of the causes and the management of gout.

DATA SOURCES

Publications on all peer-review literature from MEDLINE from 1965 to January 2004.

STUDY SELECTION

Selected and evaluated by the author.

DATA EXTRACTION

Extracted and evaluated by the author.

DATA SYNTHESIS

The underlying metabolic disorder in gout is hyperuricaemia. Most patients with hyperuricaemia remain asymptomatic throughout their lifetime. The phase of asymptomatic hyperuricaemia ends with the first attack of gouty arthritis or urolithiasis. The risk of gout and stone formation is increased with the degree and duration of hyperuricaemia. Drugs available for the treatment of acute gouty arthritis, such as non-steroidal anti-inflammatory drugs, selective cyclo-oxygenase 2 inhibitors, systemic corticosteroids, or colchicine, are effective. For periods between attacks, prophylactic therapy, such as low-dose colchicine, is effective. In those with recurrent attacks of more than two to three times yearly, a uric acid-lowering agent as a long-term therapy should be considered to avoid recurrence and the development of tophaceous gout.

CONCLUSIONS

Effective management of gout can be achieved through better understanding of the causes of the condition, preventive measures as well as drug treatment.

[Crystal-induced arthritides]

Crystal-induced arthritides are problems the general practitioner is often confronted with. Most patients present themselves more with acute than with chronic inflammatory joint diseases. However, secondary osteoarthritis is a frequent cause of disability in chronic disease. Problems of differential diagnosis arise because of constitutive symptoms such as fever and malaise in acute states of the disease and require exclusion of bacterial infection and of other systemic rheumatic diseases. This minireview will cover the clinical presentation and differential diagnosis of as well as the therapeutic approaches to the most frequent forms of crystal-induced arthritides.

Inhibitory effect of low density lipoprotein on the inflammation-inducing activity of calcium pyrophosphate dihydrate crystals

OBJECTIVE

It has been proposed that low density lipoprotein (LDL) plays a role in the self-limiting nature of pseudogout inflammation. We investigated changes of LDL concentration in rat air pouch fluid during periods of acute and subsiding inflammation to evaluate whether LDL contributes to inhibiting inflammation of pseudogout. We examined whether LDL binds to calcium pyrophosphate dihydrate (CPPD) crystals as a possible mechanism for reduction of inflammation.

METHODS

In this in vivo study, 5 mg suspensions of CPPD crystals and saline were injected into the rat air pouch. Fluid samples were taken from rat air pouch at 0, 3, 6, 12, 24, and 48 h after injection. White blood cells in the samples were counted; the remaining fluid was centrifuged and concentrations of beta-glucuronidase and PGE2 in the supernatant were measured as inflammatory markers. LDL in the supernatant was immunochemically identified by Western blotting, then pellets containing crystals were examined by the same technique.

RESULTS

LDL was identified in the air pouch 3 h after CPPD crystal injection, and its concentration increased and reached a peak level after 24 h. Inflammatory markers reached maximal level from 6 to 12 h, then decreased after 24 h. In the pellets containing crystals, LDL could not be identified in every specimen.

CONCLUSION

LDL in the rat air pouch increased during the inflammatory course induced by CPPD crystal and the inflammation subsided as the LDL increased. Since some reports indicate LDL was related to reduction of crystal induced inflammation such as gout or pseudogout, we concluded that LDL could contribute to the resolution of acute pseudogout arthritis in vivo with or without binding to CPPD crystals.

Gout-induced arthropathy after total knee arthroplasty: a report of two cases

Gout, although relatively rare in joint replacements, can present as an acute or chronic painful knee or hip arthroplasty. Gout and acute infection of a joint replacement can be difficult to differentiate, with the physical examination and laboratory study results frequently being similar. Both conditions can present with a rapid onset of joint pain, swelling, erythema, and constitutional symptoms, including fevers and malaise. Laboratory findings in both conditions often include an elevated leukocyte count, erythrocyte sedimentation rate, and C-reactive protein level. Negatively birefringent, needle-shaped crystals in the synovial fluid confirm the diagnosis of gout. The mistaken diagnosis of septic arthritis in a joint replacement with crystal-induced synovitis can lead to inappropriate open debridement or component removal. The current study includes a review of the literature and presents two cases of gout after total knee arthroplasty. These cases suggest that in situations of suspected sepsis without synovial fluid crystals, operative intervention is indicated with a presumed diagnosis of septic arthritis. The identification of chalky white or yellow deposits in the synovium or bone is highly suggestive of gout. The definitive diagnosis is made by polarized light histologic evaluation of these tissues. If these deposits are present in the absence of a positive preoperative culture, positive Gram stain for bacteria, or component loosening, component retention is indicated.

Gouty arthritis: not just a big toe problem

Gout is a metabolic disease characterized by recurrent episodes of acute arthritis. High blood levels of uric acid lead to inflammation, joint swelling, and severe pain. Treatment is aimed at relieving the acute attack and preventing recurrent episodes of gouty arthritis.

Gouty arthritis in a female patient with mixed connective tissue disease

Gout with systemic lupus erythematosus (SLE) or progressive systemic sclerosis (PSS) has rarely been reported, whereas mixed connective tissue disease (MCTD) with the demonstration of intra-articular monosodium urate crystals has never been reported. We describe an unusual case of MCTD (SLE-PSS) in a 37-year-old woman who developed acute gouty arthritis. Arthrocentesis and synovianalysis may be necessary to differentiate gout from the arthropathy of MCTD.

A practical approach to gout. Current management of an 'old' disease

Gouty arthritis is the culmination of a number of physiologic mechanisms that ultimately result in deposition of uric acid within joints and soft tissues. Decreased uric acid clearance through the kidney is the most common cause of gout. Tophaceous gout occurs in less than 10% of patients. Acute episodes are treated with NSAIDs or colchicine. Low-dose therapy with these agents can also prevent recurrent attacks. Most patients with gout need long-term treatment with either uricosuric agents or xanthine oxidase inhibitors.

[Acute gouty arthritis in adolescents with renal transplants]

Hyperuricemia is a common metabolic abnormality in subjects with renal transplantation: in fact in transplanted adults receiving immunosuppressive and diuretic drugs the frequency of hyperuricemia varied from 30 to 84% according to treatment. Conversely, the gout is an uncommon eventuality, representing less than 10%; predisposing factors are impaired renal function and older age. In the younger patients with renal transplantation hyperuricemia is also frequent, but the gout doesn't considered a possible complication in paediatric age. We reported our observation of 5 patients (3 males and 2 females), 13-18 years old who developed gout 2-84 months after renal transplantation. All the patients were receiving cyclosporine, 4 even with prednisone and azathioprine. Two patients were treated with furosemide because hypertension. The average of uric acid serum levels in the post transplantation follow-up was 7 +/- 2 mg/dl; at the moment of gout attack the uric acid serum levels raised to 12 +/- 1 mg/dl. The arthritis diagnosis were made by clinical, laboratory and instrumental data (Rx and US). In the most severe cases, uricasi therapy resolved clinical picture. The analysis of immunosuppressive and diuretic treatment, renal function and dietary uses induces us to think that the gout episode may be the result of many concomitant factors, in adolescents with renal transplant.

Hyperuricaemia in patients with right or left heart failure

Based on the clinical observation that patients with right or left heart failure often present with hyperuricaemia, the relation between serum urate values and haemodynamic variables was studied in patients with primary pulmonary hypertension (PPH) as well as in patients with advanced ischaemic heart disease or dilated cardiomyopathy. The study was a retrospective analysis of 39 patients with PPH and 36 patients with left heart disease, examining serum urate levels in association with haemodynamic variables. Elevated urate concentrations were found in 79% of the PPH patients. There was no association between serum urate levels and mean pulmonary artery pressures, but a significant correlation was found between urate levels and the cardiac index (r=0.48; p=0.0021) and an even stronger correlation between serum urate levels and mean right atrial pressures (r=0.83; p<0.0001). A similar association was found in a subgroup of 21 PPH patients not receiving diuretics. In 36 patients with ischaemic heart disease or dilated cardiomyopathy, hyperuricaemia was present in 78% and was significantly associated with elevated right atrial pressures (r=0.40; p=0.031) and even more so with elevated left atrial pressures (r=0.55; p=0.0005) but not with the cardiac index (r=0.034; p=0.86). The data show that hyperuricaemia in patients with cardiac dysfunction is closely related to elevated right or left atrial filling pressures.

[Tophaceous gout in plurimetabolic syndrome]

Aim of this paper is to describe and discuss, on the basis of the available current literature, the case of a female patient affected by a tophaceous gout associated with plurimetabolic syndrome. Hyperuricemia and gout may be seen today in all the populations of developed countries, with increasing frequency on the last fifty years. Increased production or reduced urinary excretion of uric acid (and hypoxanthine and xanthine) are the most important pathogenetic mechanisms of primary or secondary hyperuricemia. Gout is an acute rheumatic disorder (characterized by a limited range of manifestations) which occurs in humans in connection with deposition of crystals of monosodium urate (the final product of purine metabolism) in the articular and soft periarticular tissues. Hyperuricemia and/or gout are often associated with hyperinsulinemia, obesity, diabetes mellitus, hyperlipemia, hypertension and atherosclerosis to form the syndrome called "Plurimetabolic syndrome" or "Syndrome X". Here we report the clinical case of a 64-year-old female patient who had android obesity, type 2 diabetes mellitus, hypertension, dyslipidemia and hyperuricemia and had been suffering (over many years) from intermittent episodes of severe pain and inflammatory joint swelling (first metacarpo- and metatarso-phalangeal joints) with development of pronounced multiple tophi in bone articular and soft periarticular tissues. Hyperuricemia and acute episodes had never been treated with anti-hyperuricemic drugs because gouty arthritis had never been diagnosed. This severe tophaceous gout associated to multiple metabolic disorders prompted us to present knowledge on gout and to focus on the interrelationships between hyperuricemia and/or gout and plurimetabolic syndrome, important risk factors for coronary heart disease.

[Therapy of hyperuricemia and gout]

Therapy of hyperuricemia and gout has to depend on pathogenesis and stage of the disease. Dietary regimen are in the forefront in treatment of asymptomatic hyperuricemia. Uric acid lowering drugs can only be supported in repeated serum-measures from 9 mg/dl up. The therapy of an acute attack of gout primarily is done with non-steroidal antiinflammatory drugs, in rare cases with colchicine or corticoids. Gouty arthritis in intermission, independent of the extent of hyperuricemia, as well as chronic gout are indications for an uric acid lowering pharmacotherapy, usually for life. A special therapeutic challenge arises out of renal complications and the frequent association with the metabolic syndrome.

Reversible renal insufficiency, hyperuricemia and gouty arthritis in a case of hypothyroidism

We present the case of a young man with 3-month history of generalized weakness and lethargy, constipation, weight gain, and swelling in the lower extremities. He was found to have an elevated serum creatinine of 203 mumol/l (2.3 mg/dl), markedly elevated TSH, severe hypercholesterolemia, hyperuricemia, a 24-hour urine creatinine excretion rate of 16.8 mmol/d (1.9 g/d), a creatinine clearance of 58 ml/min, and a uric acid excretion rate of 4.2 mmol/d (700 mg/d). With the impression of primary hypothyroidism, the patient was started on levothyroxine supplementation at which point he developed a classic gouty arthritis of right first metatarsophalangial joint. Six weeks after thyroid replacement therapy his serum creatinine had declined to 124 mumol/l (1.4 mg/dl), and 24-hour urine creatinine excretion rate declined to 11.5 mmol/d (1.3 g/d) with an estimated creatinine clearance rate of 65 ml/min. This was accompanied by reduction in serum uric acid and cholesterol levels, and a decline in uric acid excretion rate. Eighteen months later his creatinine had further declined to 88.4 mumol/l (1.0 mg/dl).

Altered arachidonic acid metabolism in urate crystal induced inflammation

Gout is an acute rheumatic disorder that occurs in connection with the deposition of monosodium urate (MSU) crystals in the joints. This disease is characterized by intermittent episodes of severe pain and inflammatory joint swelling which are seemingly driven by prostaglandins. In this study we investigated the effect of MSU crystals on arachidonic acid (AA) metabolism in the mouse. We have demonstrated that prostaglandins and other AA metabolites were transiently formed after MSU crystal injection with peak levels occurring after 10 min. In contrast, free AA levels remained high for 2-4 hours after MSU crystal injection. By contrast, when exogenous AA was administered instead of MSU crystals, both the eicosanoids and AA diminished at the same high rates. The metabolism of exogenously administered AA to eicosanoids was inhibited by pretreatment with MSU crystals. No inhibition of AA metabolism was observed when mice were pretreated with AA itself, Ca2+ ionophore (A23187), or zymosan. We conclude that the MSU crystal treatment of mice results in a transient eicosanoid production which is followed by attenuated AA metabolism. It could be that MSU crystals similarly inhibit AA metabolism in gout and thereby limit the duration of gout attacks.

Characteristics of gouty arthritis in the Guatemalan population

The purpose of this study was to determine the characteristics of gouty arthritis in an urban Guatemalan population. We reviewed the medical records of 148 (145 males and 3 females) patients with a diagnosis of acute gouty attack seen at an urban rheumatology clinic in Guatemala City between 1982 and 1993. Mean age at diagnosis was 49 years (range 21-87), mean age of onset was 42 years, mean duration of disease 7.4 years, family history of gout 42 (28%), peak prevalence 5th decade 39 (26%). Seventy-one (48%) had monarticular, 49 (33%) oligoarticular, and 22 (15%) polyarticular attacks, respectively. Podagra was seen in 34 (23%) patients; however, 108 (73%) developed it at any moment of their life. Tophaceous gout was seen in 33 (22%). Mean serum urate concentrations (enzymatic method) were higher than 7.0 mg % in 90 (60%) patients. At follow-up, 44 (30%) patients never returned to our clinic, and a large majority of them [66 (45%)] were seen only during acute attacks. Associated disorders included hypertension (43%), obesity (27%), nephrolithiasis (16%), ischaemic heart disease (7%), renal insufficiency (2%), stroke (0.6%), and diabetes mellitus (0.6%), and two died due to sepsis; high alcoholic intake was found in 58 (39%) patients. In conclusion, our findings indicate that gout is not an unusual disorder in the Guatemalan population. It presents with the same characteristics as those reported in Caucasians, with the possible exception of a lower frequency of diabetes mellitus as an associated disorder.