Background: Long-term Arteriovenous Fistula (AVF) survival has been shown to be adversely impacted by the presence of previous Tunnelled Vascular Catheters (TVC). We analysed the effect of previous TVCs and their location (ipsilateral versus contralateral) on the successful function of upper limb AVFs in the first 12-months after creation. Methods: We retrospectively reviewed clinical data on patient's first upper limb AVFs, created between January 2013 and December 2017. We analysed the rates of successful AVF function (successful cannulation using 2 needles for ≥50% sessions over a 2-week period) at 6- and 12- months post creation, time to AVF maturation, and rates of assisted maturation. Results: 287 patients with first AVFs were identified, of which 142 patients had a previous TVC (102 contralateral, 40 ipsilateral) and 145 had no previous TVC. The No TVC group had higher rate of AVF function at both 6-months (68.6% vs 54.3%, OR 1.84, 95% CI 1.00-3.39, p=0.05) and 12-months (84.3% vs 63.5%, OR 3.10, 95% CI 1.53-6.26, p=0.002) compared to the TVC group. The Contralateral TVC group had higher rate of AVF function at 6-months (59.6% vs 40%, OR 2.21, 95% CI 1.01-4.88, p=0.05), but not at 12-months (65.9% vs 57.6%, OR 1.42, 95% CI 0.62-3.25, p=0.40) compared to the Ipsilateral TVC group. The median time to AVF maturation in the Contralateral and Ipsilateral TVC groups were 121.5 and 146 days respectively (p=0.07). Assisted maturation rates were lower in No TVC group compared to the TVC group (12.4% vs 27.9%, p=0.007), but similar between the Contralateral and Ipsilateral TVC groups (28.7% vs 25.7 %, p= 0.74). Conclusions: Previous TVC use was associated with poorer AVF function at 6- and 12-months, with a higher rate of assisted maturation. The presence of an ipsilateral TVC was associated with lower successful AVF use at 6-months, compared to contralateral TVC.

In Black South African patients with SLE, the APOL1 G1 and G2 alleles are not associated with SLE or lupus nephritis. Additionally, there is no association seen between renal function or urine protein excretion. This suggests that APOL1 G1 and G2 alleles do not play a role in SLE or lupus nephritis in the population examined. The presence of recombination within the G1 allele (rs60910145 and rs73885319), at two percent in the population examined, suggests that the concept of the G1 allele is flawed. As the G2 allele is not in HWE in the control group, while the other alleles are, this suggests that the G2 allele exerts a significant negative selective pressure on the control population, and may play a stronger physiological role, at the population level. The rs16996616 allele, despite being close to the G1 site, and a non-synonymous variant, revealed no association, furthering the case that the G2 allele may be the more physiologically potent allele