Intravenous methoxy polyethylene glycol-epoetin beta for haemoglobin control in patients with chronic kidney disease who are on dialysis: a randomised non-inferiority trial (MAXIMA)

BACKGROUND

Conventional treatment with epoetin to manage anaemia in chronic kidney disease needs frequent administrations, changes of dose, and close monitoring of haemoglobin concentrations. We aimed to compare the effectiveness of methoxy polyethylene glycol-epoetin beta, given intravenously at 2-week or 4-week intervals, with epoetin treatment one to three times per week for haemoglobin control in haemodialysis patients.

METHODS

We screened 1115 adult patients from 96 centres who had stable chronic renal anaemia and were on dialysis treatment and intravenous maintenance epoetin. We did an open-label, parallel-group, non-inferiority trial to compare two dosing intervals of methoxy polyethylene glycol-epoetin beta with standard epoetin treatment. We established baseline haemoglobin concentration and eligibility over a 4-week run-in period. 223 patients were randomly assigned to receive methoxy polyethylene glycol-epoetin beta every 2 weeks, and 224 to receive it every 4 weeks. The initial dose was based on the average epoetin dose given during the week before the switch. The primary endpoint was change in haemoglobin concentration between baseline and the assessment period. We analysed patients both by intention to treat and per protocol. This study is registered with ClinicalTrials.gov, number NCT00077610.

FINDINGS

We excluded 133 of the 673 randomised patients from the per-protocol analysis because they had inadequate iron status or fewer than five haemoglobin measurements during the assessment period or needed red blood cell transfusions. The mean change from baseline haemoglobin for patients who had switched to intravenous methoxy polyethylene glycol-epoetin beta every 2 weeks (-0.71 g/L, 95% CI -2.20 to 0.77) or every 4 weeks (-0.25 g/L, -1.79 to 1.29) was non-inferior to the mean change for patients who continued treatment with epoetin (-0.75 g/L, -2.26 to 0.75) (p<0.0001 for both comparisons). Of the 666 patients who received at least one dose of study drug, the incidence of adverse events or serious adverse events did not differ between groups (p=0.30 and p=0.40, respectively).

INTERPRETATION

This long-acting erythropoiesis-stimulating agent is as safe as conventional epoetin treatment, and can maintain anaemia management in haemodialysis patients when given intravenously at 4-week dosing intervals.

Cross-reactivity between swine leukocyte antigen and human anti-HLA-specific antibodies in sensitized patients awaiting renal transplantation

Xenotransplantation is increasingly viewed as a promising way to alleviate the problem of patients who have alloreactive lymphocytotoxic antibodies and therefore tend to accumulate on the waiting list for renal transplantation. One barrier to xenotransplantation in these patients could be the hyperacute or acute vascular rejection as a result of preexisting anti-HLA antibodies that recognize swine leukocyte antigens. The cross-reactivity of sera from 98 patients with pig lymphocytes was studied by flow cytometry. After absorption of xenoreactive natural antibodies (XNA), isotype, class, and antibody specificity causing a positive cross-match (XM) were determined. For nonsensitized patients, all of the antibody binding to pig lymphocytes was due to XNA, which were removed by pig red blood cells absorption. In contrast, in sensitized patients, after removal of XNA, pig lymphocyte XM remained positive. There was no correlation between antibody binding to pig lymphocytes and Ig isotype (IgG or IgM) or HLA class-specific antibodies. For testing evidence that class II-specific antibodies were responsible for antibody binding to pig lymphocytes, HLA class I-specific antibodies were absorbed with pooled human platelets. It was confirmed that HLA class II-specific antibodies were responsible for the positive pig XM, but the strength of the positive XM was weaker than the strength caused by HLA class I-specific antibodies. Sera with multiple specificities (plurispecific sera) displayed a greater frequency of cross-reactivity with swine leukocyte antigens (P < 0.05). Seven of 11 highly immunized patients without cross-reactivity IgG with porcine lymphocytes showed positive XM before an IgM was used. The results demonstrate the cross-reactive nature of HLA antibodies and therefore point out the need to perform a prospective XM after absorption of XNA in presensitized individuals.

Eculizumab Modifies Outcomes in Adults with Atypical Hemolytic Uremic Syndrome with Acute Kidney Injury

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is a rare disease associated with congenital or acquired genetic abnormalities that result in uncontrolled complement activation, leading to thrombotic microangiopathy and kidney failure. Until recently, the only treatment was plasma exchange or plasma infusion (PE/PI), but 60% of patients died or had permanent kidney damage despite treatment. Eculizumab, a complement inhibitor, has shown promising results in aHUS. However, data are mainly extracted from case reports or studies of heterogeneous cohorts, and no direct comparison with PE/PI is available.

METHODS

An observational retrospective study of adult, dialysis-dependent aHUS patients with acute kidney injury (AKI) who were treated with either PE/PI alone or with second-line eculizumab in our center. We compared the effect of PE/PI and eculizumab on kidney function, hypertension, proteinuria, hematologic values, relapse, and death.

RESULTS

Thirty-one patients were included (females, 18; sporadic aHUS, 29; mean age, 46 ± 20 years). Twenty-six patients were treated with PE/PI alone, and 5 were deemed to be plasma-resistant and received eculizumab after stopping PE/PI. Among patients receiving eculizumab, 80% attained complete recovery of kidney function, 100% stopped dialysis, 20% had decreased proteinuria, and no patient relapsed (vs. 38.5, 50, 15.4, and 11.5%, respectively, of patients receiving only PE/PI). At 1-year of follow-up, no deaths had occurred in either group.

CONCLUSION

Eculizumab shows greater efficacy than PE/PI alone for the treatment of adult aHUS patients with AKI. Prospective studies and meta-analyses are warranted to confirm our findings and set guidelines for treatment, monitoring, and maintenance.