Flow reduction of a high-flow arteriovenous fistula in a hemodialysis patient reveals changes in natriuretic and renin-angiotensin system hormones of relevance for kidney function.

Arteriovenous fistulas (AVFs) are iatrogenic vascular connections established to allow high-flow intravascular access for patients with chronic kidney disease requiring hemodialysis. The left-right flow shunt results in changes in extracellular fluid volume and blood pressure-controlling hormones that could affect the residual kidney function. We present a case where a female patient with a brachiocephalic AVF had a fistula flow of >4 L/min. To reduce the flow, a banding procedure was performed. The patient was examined prior to banding and 1 and 2 weeks thereafter. Banding resulted in a marked decrease in AVF flow from >4 to 1 L/min and was associated with reductions in N-terminal pro-brain natriuretic peptide of 51% and 67% at 1- and 2-weeks post-banding, respectively. Mid-regional pro-atrial natriuretic peptide concentrations were reduced post-banding by 17% after 1 week and 25% after 2 weeks. After 1 week, renin, angiotensin II, and aldosterone levels in plasma decreased transiently by 44%, 47%, and >86%, respectively, and returned to pre-banding levels after 2 weeks. Creatinine clearance tended to decrease while blood pressure and total body water increased 2 weeks after banding. This indicates that high-flow AVF is associated with increased natriuretic peptides and hormones of the renin-angiotensin-aldosterone system, that may balance each other regarding fluid retention and hypertension and support remaining kidney function.

Increased rheumatoid factor and deep venous thrombosis: 2 cohort studies of 54628 individuals from the general population.

BACKGROUND: The risk of deep venous thrombosis is increased in patients with rheumatoid arthritis. We tested the hypothesis that increased concentrations of rheumatoid factor are associated with increased risk of deep venous thrombosis in individuals without autoimmune rheumatic disease in the general population. METHODS: We included 54628 participants from the Copenhagen City Heart Study (1981-83) and the Copenhagen General Population Study (2004-12), all with a measured concentration of IgM rheumatoid factor and without autoimmune rheumatic disease or venous thromboembolism. The main outcome was incident deep venous thrombosis. There were no losses to follow-up. RESULTS: During 368381 person-years, 670 individuals developed deep venous thrombosis. A rheumatoid factor concentration ≥ vs <110 IU/mL showed the strongest association with deep venous thrombosis, with multivariable adjusted hazard ratios of 9.0 (95% CI 3.1-26) for 1-year follow-up, 4.3 (2.2-8.5) for 5-year follow-up, and 3.1 (1.7-5.6) for up to 32 years of follow-up. Compared with rheumatoid factor concentrations <15 IU/mL, the multivariable adjusted hazard ratios for deep venous thrombosis during maximum follow-up were 1.3 (1.0-1.5) for 15-29 IU/mL, 1.7 (1.0-2.8) for 30-59 IU/mL, 2.4 (1.3-4.3) for 60-119 IU/mL, and 3.0 (1.6-5.6) for ≥120 IU/mL (trend P = 6 × 10(-7)). Results were similar in the 2 studies separately. Obese men and women age >60 years with rheumatoid factor concentrations ≥120 IU/mL had 10% and 8% 5-year risk of deep venous thrombosis. CONCLUSIONS: Increased rheumatoid factor in the general population was associated with up to 3-fold increased long-term risk and up to 9-fold increased 1-year risk of deep venous thrombosis.