Prednisone lowers serum uric acid levels in patients with decompensated heart failure by increasing renal uric acid clearance

Drug-Induced Hypouricemia

Hypouricemia is defined as a serum uric acid concentration of ≤ 2.0 mg/dL or 119 μmol/L. Hypouricemia may occur secondarily to a number of underlying conditions, including severe hepatocellular disease, neoplasia, defective renal tubular reabsorption of uric acid, inherited metabolic defect in purine metabolism, and drugs. Medications are an important cause of hypouricemia. They can cause hypouricemia by a variety of mechanisms. Drug-induced hypouricemia mostly occurs as overtreatment of hyperuricemia by urate-lowering therapies including xanthine oxidase inhibitors, uricosuric agents and uricases. Drugs not used in the treatment of gout may also lead to a decrease of uric acid levels. In this literature review, medications leading to hypouricemia are summarized with regard to their mechanism of action and clinical significance.

Is Serum Uric Acid Level Associated with Disease Activity in Rheumatoid Arthritis Patients

Background

An association between serum uric acid (UA) and disease activity in rheumatoid arthritis (RA) patients has not been well studied. We describe RA patients with high and normal UA and study its association with RA activity.

Methods

Adult RA patients from the Kuwait Registry for Rheumatic Diseases (KRRD) were studied from February 2012 through March 2022. Patients with documented UA levels were included. UA of >357 µmol/L (6mg/dL) was considered high. Statistical comparison and correlation were made using multivariate logistic regression.

Results

Overall, 1054 patients with documented UA. A total of 158 patients (15%) had high UA level with a mean of 409± 44.4µmol/L. The mean age for the high UA group and low UA group were 59.3 ± 10.7 years and 54.5 ± 12.4 years, respectively (p<0.001). 49.4% were female in high UA group, and 62.2% were female in low UA group, respectively (p<0.05). Logistic analysis showed an inverse relation between DAS28 and UA, as lower DAS28 score was associated with higher UA level (p=0.032) OR 1.39. There was a direct relation with HAQ, creatinine and UA. A higher HAQ is associated with a higher UA level (p=0.019) OR 0.78. High creatinine level is also associated with high UA level (p<0.001) OR 0.24. The use of antirheumatic drugs was similar among patients with high and normal UA.

Conclusion

RA patients with a higher UA had a lower disease activity despite using similar antirheumatic drugs. The reasons behind this association need to be further studied.

Utility of muscle ultrasound in nutritional assessment of children with nephrotic syndrome

BACKGROUND

Nutritional status assessment in children with nephrotic syndrome (NS) is critical for identifying patients who are at risk of protein-energy wasting (PEW) and for determining their nutritional needs and monitoring nutritional intervention outcomes.

METHODS

In a case-control study, we enrolled 40 children (age range: 2-16 years) with NS and 40 apparently healthy children (age and sex-matched) as a control group. Anthropometric data, as well as demographic, clinical, and laboratory data, were collected. A dietary intake assessment using a 3-day food intake record was done, and the quadriceps rectus femoris thickness (QRFT) and quadriceps vastus intermedius thickness (QVIT) were assessed using B-mode ultrasound and compared between both groups.

RESULTS

Children with NS had lower QRFT and QVIT measurements than control groups (p < 0.001). Inadequacy in protein intake occurred in 62.5% and 27.5% of the NS and control groups, respectively (p = 0.002). The thickness of the rectus and vastus muscles by ultrasound was significantly associated with the percentage of protein intake (p < 0.001). The ROC curve revealed that the best cutoff value of QRFT for the prediction of the patient at risk of malnutrition was ≤ 1.195 with an area under curve of 0.907, with p < 0.001.

CONCLUSION

In children with NS, skeletal muscle ultrasound is a simple and easy-to-use bedside technique for the identification of patients at risk of malnutrition. A higher resolution version of the Graphical abstract is available as Supplementary information.

Glucocorticoids Promote Na+ Excretion in the Renal Epithelia of Heart Failure Rats by Suppressing Transporter Proteins Involved in Acute Sodium Loading

ABSTRACT

Glucocorticoid receptors are essential for normal development and stress responses. Their role in H 2 O and Na + metabolism, especially in chronic heart failure (CHF), is not well defined. In a previous study, we found that glucocorticoids potentiate urination in CHF and promote H 2 O excretion by inhibiting the vasopressin receptor 2 pathway. The present study examines the effect of glucocorticoids on renal Na + excretion and the underlying mechanisms in CHF rats with acute sodium loading. CHF was induced by left coronary artery ligation for 8 weeks. Rats were randomly assigned to 5 groups: control, CHF, dexamethasone (DEX)-administered CHF, DEX-administered CHF treated with RU486 (mifepristone, a glucocorticoid receptor antagonist), and RU486-treated CHF. An acute sodium loading test was performed 6 hours after DEX administration. Blood and urine samples were collected, and hemodynamics were measured. The expression and localization of Na + transporter proteins were determined by immunoblotting and immunohistochemistry. DEX increased the urine volume and urinary sodium and improved cardiac function and the estimated glomerular filtration rate in CHF rats. The upregulation of the epithelial sodium channel β and γ subunits, Na-K-2Cl cotransporter, serum glucocorticoid-regulated kinase 1 (SGK1), and Na + /K + -ATPase in the renal epithelium of CHF rats was downregulated by DEX. These beneficial effects were abolished by RU486. The expression of natriuretic peptide receptor A was opposite that of the above proteins. Glucocorticoids might induce profound natriuresis in CHF rats during acute sodium loading, which is associated with downregulating some Na + transporter proteins in the renal epithelium and improving intrarenal hemodynamics.

Treatment of recurrent renal transplant lithiasis: analysis of our experience and review of the relevant literature

BACKGROUND

Renal transplant lithiasis is a rather unusual disease, and the recurrence of lithiasis presents a challenging situation.

METHODS

We retrospectively analyzed the medical history of one patient who suffered renal transplant lithiasis twice, reviewed the relevant literature, and summarized the characteristics of this disease.

RESULTS

We retrieved 29 relevant studies with an incidence of 0.34 to 3.26% for renal transplant lithiasis. The summarized incidence was 0.52%, and the recurrence rate was 0.082%. The mean interval after transplantation was 33.43 ± 56.70 mo. Most of the patients (28.90%) were asymptomatic. The management included percutaneous nephrolithotripsy (PCNL, 22.10%), ureteroscope (URS, 22.65%), extracorporeal shockwave lithotripsy (ESWL, 18.60%) and conservative treatment (17.13%). In our case, the patient suffered from renal transplant lithiasis at 6 years posttransplantation, and the lithiasis recurred 16 months later. He presented oliguria, infection or acute renal failure (ARF) during the two attacks but without pain. PCNL along with URS and holmium laser lithotripsy were performed. The patient recovered well after surgery, except for a 3 mm residual stone in the calyx after the second surgery. He had normal renal function without any symptoms and was discharged with oral anticalculus drugs and strict follow-up at the clinic. Fortunately, the calculus passed spontaneously about 1 month later.

CONCLUSIONS

Due to the lack of specific symptoms in the early stage, patients with renal transplant lithiasis may have delayed diagnosis and present ARF. Minimally invasive treatment is optimal, and the combined usage of two or more procedures is beneficial for patients. After surgery, taking anticalculus drugs, correcting metabolic disorders and avoiding UIT are key measures to prevent the recurrence of lithiasis.