Mycoplasma genitalium acquisition and macrolide resistance after initiation of HIV pre-exposure prophylaxis in men who have sex with men.

OBJECTIVES: Recent evidence shows that patients using HIV pre-exposure prophylaxis (PrEP) have an increased rate of bacterial STIs, including syphilis, chlamydia and gonorrhoea. Our study aimed to describe the acquisition and the susceptibility for macrolides of Mycoplasma genitalium in men who have sex with men (MSM) on PrEP. METHODS: We studied all MSM who started PrEP in the AZ Sint-Jan Hospital Bruges from 1 June 2017 to 31 March 2019 with at least one follow-up visit. Patients were screened for M. genitalium and other STIs with pooled rectal swabs, pharyngeal swabs and first-voided urine, and blood samples at baseline and quarterly intervals after initiating PrEP. TaqMan Array Card technology was used to detect M. genitalium and determine macrolide-resistance mediating mutations in region V of the 23S rRNA gene (A2058G, A2059G, A2058C and others). Patients with an STI were treated based on a national guideline. RESULTS: 131 MSM (median age 40 years, range 20-79) were included in the study. The median follow-up time was 12 months (IQR 6.1-17). Baseline prevalence of M. genitalium was 6.9% and incidence rate after PrEP initiation was 28.8 per 100 person-years (95% CI 21.7 to 37.2), without significant differences in proportions between the first four quarterly intervals. All but one acquisitions were asymptomatic. Younger age and positivity for M. genitalium at baseline were significantly associated with incident M. genitalium acquisition. The observed proportion of macrolide resistance increased not significantly from 44% at baseline to 57%-86% after PrEP initiation. None of the 27 macrolide-resistant M. genitalium acquisitions could be linked to azithromycin exposure in the three preceding months. CONCLUSIONS: After initiation of PrEP, we found a stable incidence of almost exclusively asymptomatic M. genitalium. However, a non-significant trend of an increased percentage of macrolide-resistant strains was observed.

Hemodialysis catheter design and catheter performance: a randomized controlled trial.

BACKGROUND: A complication of long-term use of tunneled cuffed catheters for hemodialysis is the high rate of infection and thrombus-related dysfunction. Specific mechanical features of tunneled cuffed catheters may improve hemodynamic performance and decrease thrombosis and infection rates. However, there currently is no proven advantage of one design over another. STUDY DESIGN: Single-center randomized clinical trial. SETTING & PARTICIPANTS: 302 hemodialysis patients who required a tunneled cuffed catheter as temporary or definite vascular access. INTERVENTION: Palindrome Symmetric Tip Dialysis Catheter or HemoStar Long-Term Hemodialysis Catheter. OUTCOMES & MEASUREMENTS: The primary end point was primary assisted patency. Secondary end points were incidence of catheter-related bloodstream infections (CRBSIs), thrombosis, and 2 indicators of rheologic function: mean effective blood flow rate and urokinase use. RESULTS: Mean primary assisted patency was 135.9 days for Palindrome and 136.5 days for HemoStar (P=0.8). Definite CRBSI occurred in 0.24 and 0.10/1,000 catheter-days for Palindrome and HemoStar, respectively (P=0.3). Removal rates for thrombosis that could not be resolved with thrombolysis were 0.53 and 0.43/1,000 catheter-days for Palindrome and HemoStar, respectively (P=0.7). Urokinase use was lower for Palindrome than for HemoStar, as evidenced by a lower number of urokinase infusions/1,000 catheter-days (17 and 35; P<0.001) and higher number of catheters that never required thrombolysis (58% and 45%; P=0.03). Mean effective blood flow rate was higher for Palindrome than for HemoStar (333 and 304mL/min; P<0.001). LIMITATIONS: Single-center nonblinded trial. CONCLUSIONS: Primary assisted patency and incidence of infection and thrombosis were similar for both catheter types. The Palindrome catheter required less thrombolysis and achieved higher blood flow rates than the HemoStar catheter. These findings suggest that mechanical catheter design may improve catheter rheology, but does not affect risks for thrombosis and infection and hence catheter survival.

Should we screen for coronary artery disease in asymptomatic chronic dialysis patients?

The hemodialysis population is characterized by a high prevalence of 'asymptomatic' coronary artery disease (CAD), which should be interpreted differently from asymptomatic disease in the general population. A hemodynamically significant stenosis may not become clinically apparent owing to impaired exercise tolerance and autonomic neuropathy. The continuous presence of silent ischemia may cause heart failure, arrhythmias, and sudden death. Whether revascularization of an asymptomatic dialysis patient improves outcome remains a moot point, although several observational studies and one small RCT suggest a benefit. It can therefore be defended to screen asymptomatic dialysis patients for CAD. A number of noninvasive screening tests are available, but none has proved equally practical and reliable in the dialysis population as in the general population. Myocardial perfusion scintigraphy (MPS) before and after a pharmacological stress such as dipyridamole can reveal both ischemia and myocardial scarring. When compared with coronary angiography, low sensitivities were reported and attributed to impaired vasodilation to dipyridamole in dialysis patients. A more likely explanation is that not every anatomical stenosis will lead to impaired coronary blood flow on MPS. Numerous studies have shown an incremental prognostic value of dipyridamole-MPS over clinical data for prediction of adverse cardiac events, in some studies even over coronary angiography. Pending the availability of high-quality evidence, in our opinion asymptomatic dialysis patients could undergo dipyridamole-MPS, followed by coronary angiography in case of an abnormal scan. This combined physiological and anatomical evaluation of the coronary circulation allows us to determine which coronary stenosis is clinically relevant and therefore should be revascularized.

Calcium metabolism in the early posttransplantation period.

BACKGROUND AND OBJECTIVES: Information on the time course of serum calcium levels after renal transplantation is scanty, especially in the early posttransplantation period. Both the abrupt cessation of calcium-containing phosphorus binders and vitamin D (analogs) at the time of surgery and the recovery of renal function may be hypothesized to affect serum calcium levels in this period. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this prospective observational study, biointact parathyroid hormone, calcidiol, calcitriol, calcium, and phosphorus levels were monitored in 201 renal transplant recipients at the time of transplantation and 3 mo thereafter. In addition, the serum calcium nadir and peak in each individual patient within this time frame were identified and the urinary fractional calcium excretion was determined at month 3. RESULTS: Serum calcium levels followed a biphasic pattern with a significant decline during the first postoperative week, followed by a significant increase. High pretransplantation parathyroid hormone levels protect against hypocalcemia within the first postoperative week but put patients at risk for hypercalcemia later. These complications, occurring in 41 and 14% of the patients, respectively, most probably reflect inappropriate calcium release from the skeleton, rather than inappropriate renal calcium handling. CONCLUSIONS: Our data indicate that both hypo- and hypercalcemia are prevalent in the early posttransplantation period. Pretransplantation parathyroid function is an important predictor of posttransplantation calcium levels.