Concentration-controlled treatment of lupus nephritis with mycophenolate mofetil

Background:

Mycophenolate mofetil (MMF) has recently been established as a potent drug in maintenance treatment for lupus nephritis. However, there is no consensus on the optimal dosing regimen because of a high inter-individual variability of mycophenolic acid (MPA), the active metabolite of MMF. This retrospective study aimed to investigate the effect of an individualized dosing regimen through concentration-controlled treatment on MPA exposure and renal outcome in patients with lupus nephritis.

Methods:

Sixteen patients with lupus nephritis and treatment with low-dose intravenous cyclophosphamide followed by MMF were included. MPA area under the plasma concentration-time curve from 0 to 12 hours (MPA-AUC0–12) was assessed within a month after MMF initiation. After determination of MPA-AUC0–12, MMF doses were titrated to achieve a target MPA-AUC0–12 of 60–90 mg*h/l. After on average six months, MPA-AUC0–12 measures were repeated to assess the effect of dose adjustment.

Results:

One month after introducing MMF, MPA-AUC0–12 was low and showed a high inter-individual variability. Dose adjustment with a target MPA-AUC0–12 of 60–90 mg*h/l resulted in individualized MMF dosing, significantly higher MPA-AUC0–12 levels, and a non-significant reduction in variability of MPA-AUC0–12. Adverse effects were reported by 37.5% of patients, which resulted in a switch to azathioprine in two patients. There was no significant relationship between the occurrence of adverse effects and MPA-AUC0–12. At 12 months of follow-up 87.5% of patients had achieved either partial (18.7%) or complete (68.8%) remission.

Conclusion:

Concentration-controlled dose adjustments with a target MPA-AUC0–12 of 60–90 mg*h/l was associated with optimized MPA exposure and an excellent renal outcome at 12 months of follow-up in a small sample of SLE patients with lupus nephritis.

Illness perceptions in patients with systemic lupus erythematosus and proliferative lupus nephritis

This study investigated the illness perceptions of patients with systemic lupus erythematosus (SLE) and whether perceptions are influenced by type of treatment for proliferative lupus nephritis. In addition, the illness perceptions of SLE patients were compared with those of patients with other chronic illnesses. Thirty-two patients who had experienced at least one episode of proliferative lupus nephritis were included. Patients were treated with either a high or low-dose cyclophosphamide (CYC) regimen (National Institutes of Health [NIH] vs. Euro-Lupus protocol). Illness perceptions were measured with the Brief Illness Perception Questionnaire (B-IPQ) and a drawing assignment. The low-dose CYC group perceived their treatment as more helpful than the high-dose CYC group. In comparison with patients with asthma, SLE patients showed more negative illness perceptions on five of the eight illness perception domains. Drawings of the kidney provided additional information about perceptions of treatment effectiveness, kidney function and patients' understanding of their illness. Drawing characteristics showed associations with perceptions of consequences, identity, concern and personal control. These findings suggest that the type of treatment SLE patients with proliferative lupus nephritis receive may influence perceptions of treatment effectiveness. In addition, patients' drawings reveal perceptions of damage caused by lupus nephritis to the kidneys and the extent of relief provided by treatment. The finding that SLE is experienced as a more severe illness than other chronic illnesses supports the need to more frequently assess and aim to improve psychological functioning in SLE patients.