Publications

BACKGROUND

Chronic kidney disease (CKD) progression can be a cause and potentially a consequence of anemia. Previous studies suggesting that anemia is associated with CKD progression have not utilized methodologic approaches to address time-dependent confounding.

METHODS

We evaluated the association of anemia (defined using World Health Organization criteria of hemoglobin <12 g/dL in women and <13 g/dL in men) with incident ESRD and all-cause death in individuals with CKD using data from the Chronic Renal Insufficiency Cohort Study. Marginal structural models were used to account for time-dependent confounding.

RESULTS

Among 3919 participants, 1859 (47.4%) had anemia at baseline. Over median follow up of 7.8 years, we observed 1,010 ESRD events and 994 deaths. In multivariable analyses, individuals with anemia had higher risk for ESRD compared to those without (HR 1.62, 95% CI 1.24-2.11). In stratified analyses, the increased risk for incident ESRD with anemia was observed in males (HR 2.15, 95% CI: 1.53-3.02) but not females (HR 1.20, 95% CI 0.82-1.78. The association between anemia and ESRD was significant among all racial/ethnic groups except non-Hispanic blacks (non-Hispanic white, HR 2.16, 95% CI 1.53-3.06; Hispanic, HR 1.92, 1.04-3.51; others, HR 2.94; 95% CI 1.16-7.44; non-Hispanic black, HR 1.39; 95% CI 0.95-2.02). There was no association between anemia and all-cause death.

CONCLUSIONS

In this cohort, anemia was independently associated with increased risk for incident ESRD. Future work is needed to evaluate the mechanisms by which anemia leads to CKD progression as well as the impact of novel therapeutic agents to treat anemia.

Ruxolitinib, a selective Janus kinase (JAK)1/2 inhibitor, has recently been proposed for steroid-refractory chronic graft-versus host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT), particularly in severe skin cGVHD. Lung function impairment is common in severe skin cGVHD through concomitant bronchiolitis obliterans syndrome (BOS) or restrictive lung disease (RLD) from skin sclerosis. To date, no treatment has shown a benefit on lung function in this context. We retrospectively assessed the effect of ruxolitinib on lung function in a cohort of 70 patients diagnosed with sclerotic-type skin cGVHD between March 2015 and April 2018. Among these patients, 36 received ruxolitinib. To handle confounding by indication bias, exposure groups were matched on the propensity score to receive ruxolitinib, incorporating age, myeloablative conditioning, total body irradiation, BOS, forced expiratory volume in 1 second (FEV), forced vital capacity (FVC), and tobacco use at the time of cohort entry, as well as the time from transplantation. The 1:1 matching used a greedy-matching algorithm with replacement, with a caliper of 0.10. FVC and FEV trajectories during follow-up were compared in the matched samples, using linear mixed-effects models. The median duration of follow-up of the 46 matched patients was 58 months (interquartile range, 32 to 84 months). Ten patients had an RLD (6 exposed, 4 unexposed), and 13 patients were diagnosed with BOS (8 exposed, 5 unexposed). FEV decreased significantly over time independent of exposure to ruxolitinib (P < .0001). The FEV trajectory was similar in the exposed patients and the unexposed patients (P = .11). In conclusion, ruxolitinib administration did not demonstrate any improvement in the course of respiratory function in allogeneic HSCT recipients with sclerotic-type skin cGVHD.