An unusual case of gout in the wrist: the importance of monitoring medication dosage and interaction. A case report

<p>Abstract</p> <p>Background</p> <p>Gouty arthritis of the wrist is uncommon although gout itself is the most common inflammatory arthritis in older patients. Some known risk factors for the development of gout include trauma, alcohol use, obesity, hyperuricaemia, hypertension and diabetes mellitus. As well, certain medications have been shown to promote the development of gout. These include thiazide diuretics, low dose salicylates and cyclosporine. We present a case of gouty wrist pain possibly precipitated by a medication dosage increase as well as medication interactions.</p> <p>Case presentation</p> <p>A 77 year old male presented with right wrist pain. Redness and swelling was present at the dorsal aspect of his wrist and range of motion was full with pain at end range upon examination. One week prior, his anti-hypertensive medication dosage had been increased. The patient's situation continued to worsen. Radiographic examination revealed changes consistent with gouty arthritis.</p> <p>Conclusion</p> <p>It is important for clinicians treating joint conditions to be aware of patients' comorbidities, medication usage and changes in dosages. Education of patients with gout is of prime importance. Clinicians should educate patients that gout may occur at any joint in the body not only the lower limb. Patients should be aware of the signs and symptoms of an acute gouty attack and be made aware that changes in certain medication dosages may precipitate an attack. Awareness of radiographic changes associated with gout is still of importance although these changes are not seen as frequently as they have been in the past due to better control of the disease.</p

Polymorphisms in the Presumptive Promoter Region of the SLC2A9 Gene Are Associated with Gout in a Chinese Male Population

BACKGROUND: Glucose transporter 9 (GLUT9) is a high-capacity/low-affinity urate transporter. To date, several recent genome-wide association studies (GWAS) and follow-up studies have identified genetic variants of SLC2A9 associated with urate concentrations and susceptibility to gout. We therefore investigated associations between gout and polymorphisms and haplotypes in the presumptive promoter region of GLUT9 in Chinese males. METHODOLOGY/PRINCIPAL FINDINGS: The approximately 2000 bp presumptive promoter region upstream of the start site of exon 1 of GLUT9 was sequenced and subjected to genetic analysis. A genotype-phenotype correlation was performed and polymorphisms-induced changes in transcription factor binding sites were predicted. Of 21 SNPs identified in GLUT9, five had not been previously reported. Two of the SNPs (rs13124007 and rs6850166) were associated with susceptibility to gout (p = 0.009 and p = 0.042, respectively). The C allele of rs13124007 appeared to be the risk allele for predisposition to gout (p = 0.006, OR 1.709 [95% CI 1.162-2.514]). For rs6850166, an increased risk of gout was associated with the A allele (p = 0.029, OR 1.645 [95% CI 1.050-2.577]). After Bonferroni correction, there was statistically difference in rs13124007 allele frequencies between gout cases and controls (P = 0.042). Haplotype analyses showed that haplotype GG was a protective haplotype (p = 0.0053) and haplotype CA was associated with increased risk of gout (p = 0.0326). Genotype-phenotype analysis among gout patients revealed an association of rs13124007 with serum triglycerides levels (P = 0.001). The C to G substitution in polymorphism rs13124007 resulted in a loss of a binding site for transcription factor interferon regulatory factor 1 (IRF-1). CONCLUSIONS/SIGNIFICANCE: Polymorphisms rs13124007 and rs6850166 are associated with susceptibility to gout in Chinese males

Identification of the Inorganic Pyrophosphate Metabolizing, ATP Substituting Pathway in Mammalian Spermatozoa

Inorganic pyrophosphate (PPi) is generated by ATP hydrolysis in the cells and also present in extracellular matrix, cartilage and bodily fluids. Fueling an alternative pathway for energy production in cells, PPi is hydrolyzed by inorganic pyrophosphatase (PPA1) in a highly exergonic reaction that can under certain conditions substitute for ATP-derived energy. Recombinant PPA1 is used for energy-regeneration in the cell-free systems used to study the zymology of ATP-dependent ubiquitin-proteasome system, including the role of sperm-borne proteasomes in mammalian fertilization. Inspired by an observation of reduced in vitro fertilization (IVF) rates in the presence of external, recombinant PPA1, this study reveals, for the first time, the presence of PPi, PPA1 and PPi transporter, progressive ankylosis protein ANKH in mammalian spermatozoa. Addition of PPi during porcine IVF increased fertilization rates significantly and in a dose-dependent manner. Fluorometric assay detected high levels of PPi in porcine seminal plasma, oviductal fluid and spermatozoa. Immunofluorescence detected PPA1 in the postacrosomal sheath (PAS) and connecting piece of boar spermatozoa; ANKH was present in the sperm head PAS and equatorial segment. Both ANKH and PPA1 were also detected in human and mouse spermatozoa, and in porcine spermatids. Higher proteasomal-proteolytic activity, indispensable for fertilization, was measured in spermatozoa preserved with PPi. The identification of an alternative, PPi dependent pathway for ATP production in spermatozoa elevates our understanding of sperm physiology and sets the stage for the improvement of semen extenders, storage media and IVF media for animal biotechnology and human assisted reproductive therapies

African American patients with gout: efficacy and safety of febuxostat vs allopurinol

<p>Abstract</p> <p>Background</p> <p>African Americans are twice as likely as Caucasians to develop gout, but they are less likely to be treated with urate-lowering therapy (ULT). Furthermore, African Americans typically present with more comorbidities associated with gout, such as hypertension, obesity, and renal impairment. We determined the efficacy and safety of ULT with febuxostat or allopurinol in African American subjects with gout and associated comorbidities and in comparison to Caucasian gout subjects.</p> <p>Methods</p> <p>This is a secondary analysis of the 6-month Phase 3 CONFIRMS trial. Eligible gouty subjects with baseline serum urate (sUA) ≥ 8.0 mg/dL were randomized 1:1:1 to receive febuxostat 40 mg, febuxostat 80 mg, or allopurinol (300 mg or 200 mg depending on renal function) daily. All subjects received gout flare prophylaxis. Primary efficacy endpoint was the proportion of subjects in each treatment group with sUA < 6.0 mg/dL at the final visit. Additional endpoints included the proportion of subjects with mild or with moderate renal impairment who achieved a target sUA < 6.0 mg/dL at final visit. Adverse events (AEs) were recorded throughout the study.</p> <p>Results</p> <p>Of the 2,269 subjects enrolled, 10.0% were African American and 82.1% were Caucasian. African American subjects were mostly male (89.5%), obese (BMI ≥ 30 kg/m²; 67.1%), with mean baseline sUA of 9.8 mg/dL and mean duration of gout of 10.4 years. The proportions of African American subjects with a baseline history of diabetes, renal impairment, or cardiovascular disease were significantly higher compared to Caucasians (<it>p </it>< 0.001). ULT with febuxostat 80 mg was superior to both febuxostat 40 mg (<it>p </it>< 0.001) and allopurinol (<it>p </it>= 0.004). Febuxostat 40 mg was comparable in efficacy to allopurinol. Significantly more African American subjects with mild or moderate renal impairment achieved sUA < 6.0 mg/dL in the febuxostat 80 group than in either the febuxostat 40 mg or allopurinol group (<it>p </it>< 0.05). Efficacy rates in all treatment groups regardless of renal function were comparable between African American and Caucasian subjects, as were AE rates.</p> <p>Conclusions</p> <p>In African American subjects with significant comorbidities, febuxostat 80 mg is significantly more efficacious than either febuxostat 40 mg or allopurinol 200/300 mg. Febuxostat was well tolerated in this African American population.</p> <p>Please see related article: <url>http://www.biomedcentral.com/1741-7015/10/15</url></p

Interrogation of the perturbed gut microbiota in gouty arthritis patients through in silico metabolic modeling

Recent studies have shown perturbed gut microbiota associated with gouty arthritis, a metabolic disease characterized by an imbalance between uric acid production and excretion. To mechanistically investigate altered microbiota metabolism associated with gout disease, 16S rRNA gene amplicon sequence data from stool samples of gout patients and healthy controls were computationally analyzed through bacterial community metabolic models. Patient-specific community models constructed with the metagenomics modeling pipeline, mgPipe, were used to perform k-means clustering of samples according to their metabolic capabilities. The clustering analysis generated statistically significant partitioning of samples into a Bacteroides-dominated, high gout cluster and a Faecalibacterium-elevated, low gout cluster. The high gout cluster was predicted to allow elevated synthesis of the amino acids D-alanine and L-alanine and byproducts of branched-chain amino acid catabolism, while the low gout cluster allowed higher production of butyrate, the sulfur-containing amino acids L-cysteine and L-methionine, and the L-cysteine catabolic product H2S. By expanding the capabilities of mgPipe to provide taxa-level resolution of metabolite exchange rates, acetate, D-lactate and succinate exchanged from Bacteroides to Faecalibacterium were predicted to enhance butyrate production in the low gout cluster. Model predictions suggested that sulfur-containing amino acid metabolism generally and H2S more specifically could be novel gout disease markers

Renal amyloidosis in children

Renal amyloidosis is a detrimental disease caused by the deposition of amyloid fibrils. A child with renal amyloidosis may present with proteinuria or nephrotic syndrome. Chronic renal failure may follow. Amyloid fibrils may deposit in other organs as well. The diagnosis is through the typical appearance on histopathology. Although chronic infections and chronic inflammatory diseases used to be the causes of secondary amyloidosis in children, the most frequent cause is now autoinflammatory diseases. Among this group of diseases, the most frequent one throughout the world is familial Mediterranean fever (FMF). FMF is typically characterized by attacks of clinical inflammation in the form of fever and serositis and high acute-phase reactants. Persisting inflammation in inadequately treated disease is associated with the development of secondary amyloidosis. The main treatment is colchicine. A number of other monogenic autoinflammatory diseases have also been identified. Among them cryopyrin-associated periodic syndrome (CAPS) is outstanding with its clinical features and the predilection to develop secondary amyloidosis in untreated cases. The treatment of secondary amyloidosis mainly depends on the treatment of the disease. However, a number of new treatments for amyloid per se are in the pipeline

Characterization of Granulations of Calcium and Apatite in Serum as Pleomorphic Mineralo-Protein Complexes and as Precursors of Putative Nanobacteria

Calcium and apatite granulations are demonstrated here to form in both human and fetal bovine serum in response to the simple addition of either calcium or phosphate, or a combination of both. These granulations are shown to represent precipitating complexes of protein and hydroxyapatite (HAP) that display marked pleomorphism, appearing as round, laminated particles, spindles, and films. These same complexes can be found in normal untreated serum, albeit at much lower amounts, and appear to result from the progressive binding of serum proteins with apatite until reaching saturation, upon which the mineralo-protein complexes precipitate. Chemically and morphologically, these complexes are virtually identical to the so-called nanobacteria (NB) implicated in numerous diseases and considered unusual for their small size, pleomorphism, and the presence of HAP. Like NB, serum granulations can seed particles upon transfer to serum-free medium, and their main protein constituents include albumin, complement components 3 and 4A, fetuin-A, and apolipoproteins A1 and B100, as well as other calcium and apatite binding proteins found in the serum. However, these serum mineralo-protein complexes are formed from the direct chemical binding of inorganic and organic phases, bypassing the need for any biological processes, including the long cultivation in cell culture conditions deemed necessary for the demonstration of NB. Thus, these serum granulations may result from physiologically inherent processes that become amplified with calcium phosphate loading or when subjected to culturing in medium. They may be viewed as simple mineralo-protein complexes formed from the deployment of calcification-inhibitory pathways used by the body to cope with excess calcium phosphate so as to prevent unwarranted calcification. Rather than representing novel pathophysiological mechanisms or exotic lifeforms, these results indicate that the entities described earlier as NB most likely originate from calcium and apatite binding factors in the serum, presumably calcification inhibitors, that upon saturation, form seeds for HAP deposition and growth. These calcium granulations are similar to those found in organisms throughout nature and may represent the products of more general calcium regulation pathways involved in the control of calcium storage, retrieval, tissue deposition, and disposal

Regulation of Cementoblast Gene Expression by Inorganic Phosphate In Vitro

Examination of mutant and knockout phenotypes with altered phosphate/pyrophosphate distribution has demonstrated that cementum, the mineralized tissue that sheathes the tooth root, is very sensitive to local levels of phosphate and pyrophosphate. The aim of this study was to examine the potential regulation of cementoblast cell behavior by inorganic phosphate (P i ). Immortalized murine cementoblasts were treated with P i in vitro , and effects on gene expression (by quantitative real-time reverse-transcriptase polymerase chain reaction [RT-PCR]) and cell proliferation (by hemacytometer count) were observed. Dose-response (0.1–10 mM) and time-course (1–48 hours) assays were performed, as well as studies including the Na-P i uptake inhibitor phosphonoformic acid. Real-time RT-PCR indicated regulation by phosphate of several genes associated with differentiation/mineralization. A dose of 5 mM P i upregulated genes including the SIBLING family genes osteopontin ( Opn , >300% of control) and dentin matrix protein-1 ( Dmp-1 , >3,000% of control). Another SIBLING family member, bone sialoprotein ( Bsp ), was downregulated, as were osteocalcin ( Ocn ) and type I collagen ( Col1 ). Time-course experiments indicated that these genes responded within 6–24 hours. Time-course experiments also indicated rapid regulation (by 6 hours) of genes concerned with phosphate/pyrophosphate homeostasis, including the mouse progressive ankylosis gene ( Ank ), plasma cell membrane glycoprotein-1 ( Pc-1 ), tissue nonspecific alkaline phosphatase ( Tnap ), and the Pit1 Na-P i cotransporter. Phosphate effects on cementoblasts were further shown to be uptake-dependent and proliferation-independent. These data suggest regulation by phosphate of multiple genes in cementoblasts in vitro . During formation, phosphate and pyrophosphate may be important regulators of cementoblast functions including maturation and regulation of matrix mineralization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48015/1/223_2005_Article_184.pd