[Amoxicillin induced crystal nephropathy : Monitoring of residual plasma levels]. / Cristalluries sous amoxicilline : intérêt du monitoring des concentrations plasmatiques résiduelles.

Since 2010, a lot of cases of amoxicillin induced crystal nephropathy have been reported to the French pharmacovigilance centers partly due to the high doses recommended by infectious disease guidelines. Typical clinical presentation and exclusion of others toxics or immuno-allergic causes are mandatory to assess the diagnostic. Amoxicillin crystals are rarely found or searched and renal biopsy is not frequently performed due to technical reasons and prompt renal recovery after antibiotics withdrawal. Monitoring of residual plasma concentration is rarely used in clinical practice for diagnostic or prognostic interest. We present 9 consecutive cases of acute kidney injury suspected to be due to amoxicillin crystals with residuals plasma levels to disclose a predictive threshold of tubulopathy. All patients had a high residual rate at diagnosis but we cannot find a threshold that would allow to adapt the antibiotic dose, enhance hydratation and alkalinizide urine to increase the medication solubility and limit renal toxicity.

A Case of Pneumocystis jirovecii Pneumonia under Belatacept and Everolimus: Benefit-Risk Balance between Renal Allograft Function and Infection.

Pneumocystis jirovecii pneumonia is an opportunistic disease usually prevented by trimethoprim-sulfamethoxazole. A 49-year-old HLA-sensitized male with successful late conversion from tacrolimus-based to belatacept-based immunosuppression developed P. jirovecii pneumonia for which he presented several risks factors: low lymphocyte count with no CD4+ T cells detected since 2 years, hypogammaglobulinemia, history of acute cellular rejection 3 years before, and immunosuppressive treatment (belatacept, everolimus). Because of respiratory gravity in the acute phase, the patient was given oxygen, corticosteroids, and trimethoprim-sulfamethoxazole. Thanks to the improvement of respiratory status, and because of the renal impairment, trimethoprim-sulfamethoxazole was converted to atovaquone for 21 days. Indeed, after 1 week on intensive treatment, the benefit-risk balance favored preserving renal function according to respiratory improvement status. P. jirovecii pneumonia prophylaxis for the next 6 months was monthly aerosol of pentamidine. Long-term safety studies or early/late conversion to belatacept did not report on P. jirovecii pneumonia. Four other cases of P. jirovecii pneumonia under belatacept therapy were previously described in patients having no P. jirovecii pneumonia prophylaxis. Studies on the reintroduction of P. jiroveciipneumonia prophylaxis after conversion to belatacept would be of interest. It could be useful to continue regular evaluation within the second-year post-transplantation regarding immunosuppression: T-cell subsets and immunoglobulin G levels.