High intra-individual variability of cyclosporine pharmacokinetics in lung transplant recipients without cystic fibrosis

Lung transplantation: Current insights and outcomes

Until now, the ability to predict or retard immune-mediated rejection events after lung transplantation is still limited due to the lack of specific biomarkers. The pressing need remains to early diagnose or predict the onset of chronic lung allograft dysfunction (CLAD) and its differential phenotypes that is the leading cause of death. Omics technologies (mainly genomics, epigenomics, and transcriptomics) combined with advanced bioinformatic platforms are clarifying the key immune-related molecular routes that trigger early and late events of lung allograft rejection supporting the biomarker discovery. The most promising biomarkers came from genomics. Both unregistered and NIH-registered clinical trials demonstrated that the increased percentage of donor-derived cell-free DNA in both plasma and bronchoalveolar lavage fluid showed a good diagnostic performance for clinically silent acute rejection events and CLAD differential phenotypes. A further success arose from transcriptomics that led to development of Molecular Microscope® Diagnostic System (MMDx) to interpret the relationship between molecular signatures of lung biopsies and rejection events. Other immune-related biomarkers of rejection events may be exosomes, telomer length, DNA methylation, and histone-mediated neutrophil extracellular traps (NETs) but none of them entered in registered clinical trials. Here, we discuss novel and existing technologies for revealing new immune-mediated mechanisms underlying acute and chronic rejection events, with a particular focus on emerging biomarkers for improving precision medicine of lung transplantation field.

A meta-analysis of cyclosporine treatment for Stevens-Johnson syndrome/toxic epidermal necrolysis

Background

Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are dermatologic emergencies with high morbidity and mortality risk. Cyclosporine, an immunomodulatory agent, is sometimes used off-label, and its role continues to be debated. This meta-analysis aimed to provide an update of current evidence and to clarify the role of cyclosporine in SJS/TEN treatment better.

Methods

Using the keywords [cyclosporine OR cyclosporine OR ciclosporin OR CsA] AND [Steven-Johnson OR SJS OR toxic epidermal OR epidermal necrolysis OR TEN OR hypersensitivity OR dermatologic OR burns], a preliminary search on the PubMed, Ovid, Web of Science, and Google Scholar Database yielded 615 papers published in English between January1, 1960 and July 1, 2017. The inclusion criteria for this review were: 1) published retrospective or prospective study (excluding single case reports); 2) patients with clinical diagnosis of SJS or TEN; 3) trial of cyclosporine treatment; and 4) available survival/mortality data.

Results

A total of 12 studies, with a total of 358 SJS/TEN patients were reviewed. Two studies were excluded from the meta-analysis as they did not report SCORe of toxic epidermal necrosis/predicted mortality data; one was excluded because of possible data irregularities. Meta-analysis of nine studies revealed a significant reduction in mortality risk with cyclosporine therapy (standardized mortality ratio 0.320; 95% CI: 0.119–0.522; P=0.002). Cyclosporine was also generally well tolerated with little adverse effects or increased infection, albeit the patients tended to be critically ill. Publication bias was observed in the funnel plot and Egger test (P=0.0467).

Conclusion

Currently available evidence are predominantly open trials and retrospective studies with a significant risk of bias, perhaps owing to the rarity and life-threatening nature of the condition. Given its immunomodulatory actions, cyclosporine could be a potential treatment option for SJS/TEN in addition to best supportive measures. Further confirmation with robust randomized, controlled trials or larger case series is necessary and should be encouraged.

Unexplained spikes in lamotrigine serum concentration: nonlinear elimination?

OBJECTIVES

The objective of this study was to evaluate possible nonlinear lamotrigine (LTG) pharmacokinetics at elevated concentration. LTG is reported to have linear kinetics, so that elimination rate is linearly proportional to blood concentration and a change in dose is accompanied by a proportionate change in serum concentration. We encountered patients in whom LTG serum concentration increased dramatically in response to minor or no change in LTG dose. We studied this phenomenon in patients with LTG toxicity in one clinic.

MATERIALS AND METHODS

Using electronic medical records from 1997 to 2014, we identified patients who developed clinical LTG toxicity with LTG serum concentrations >20 mg/l, after tolerating lamotrigine at lower serum concentrations. We reviewed LTG dose change and other changes that preceded the episode of toxicity.

RESULTS

Twenty-two patients had at least one episode of LTG toxicity with levels higher than 20 mg/l (of 922 patients with available levels). The peak serum concentration varied from 21.1 to 40.3 mg/l (mean 28.7). The increase in level was explained in three patients (post-delivery in one, addition of valproate in two). In the 18 others, the increase was not explained or it was disproportionate to an increase in LTG dose.

CONCLUSIONS

Spikes in LTG levels and associated clinical toxicity may occur unexpectedly, suggesting that elimination kinetics may be nonlinear in some individuals at serum concentrations in the upper range. Measurement and close monitoring of LTG levels is warranted for new symptoms that could be consistent with lamotrigine toxicity, particularly when the baseline serum concentration has been >10 mg/l.