Selection of Pneumocystis jirovecii Inosine 5'-Monophosphate Dehydrogenase Mutants in Solid Organ Transplant Recipients: Implication of Mycophenolic Acid

Mycophenolic acid (MPA) targets the inosine 5'-monophosphate dehydrogenase (IMPDH) of human lymphocytes. It is widely used as an immunosuppressant to prevent rejection in solid organ transplant (SOT) recipients who, incidentally, are at risk for Pneumocystis pneumonia (PCP). We hypothesized that MPA exerts selective pressure on P. jirovecii microorganisms considering its in vitro antifungal activity on other fungi. Thus, we analysed impdh gene in P. jirovecii isolates from SOT recipients. P. jirovecii specimens from 26 patients diagnosed with PCP from 2010 to 2020 were retrospectively examined: 10 SOT recipients treated with MPA and 16 non-SOT patients without prior exposure to MPA. The P. jirovecii impdh gene was amplified and sequenced. Nucleotide sequences were aligned with the reference sequences retrieved from available P. jirovecii whole genomes. The deduced IMPDH protein sequences were aligned with available IMPDH proteins from Pneumocystis spp. and other fungal species known to be in vitro sensitive or resistant to MPA. A total of nine SNPs was identified. One SNP (G1020A) that results in an Ala261Thr substitution was identified in all SOT recipients and in none of the non-SOT patients. Considering that IMPDHs of other fungi, resistant to MPA, harbour Thr (or Ser) at the analogous position, the Ala261Thr mutation observed in MPA-treated patients was considered to represent the signature of P. jirovecii exposure to MPA. These results suggest that MPA may be involved in the selection of specific P. jirovecii strains that circulate in the SOT recipient population.

The shift from pulmonary colonization to Pneumocystis pneumonia

Pulmonary specimen pairs from five patients who presented with pulmonary colonization and later developed Pneumocystis Pneumonia (PcP) were retrospectively examined for P. jirovecii genotyping. A match of genotypes in pulmonary specimen pairs of three patients was observed, whereas a partial match and a mismatch were observed in the fourth and fifth patients, respectively. The genotyping results suggest that the colonization state can differ from PcP but can also represent the incubation period of PcP. Clinicians should not systematically rule out the treatment of putative colonized patients and should at least discuss the initiation of prophylaxis on a case-by-case basis.

Belatacept and Long-Term Outcomes in Kidney Transplantation

BACKGROUND

In previous analyses of BENEFIT, a phase 3 study, belatacept-based immunosuppression, as compared with cyclosporine-based immunosuppression, was associated with similar patient and graft survival and significantly improved renal function in kidney-transplant recipients. Here we present the final results from this study.

METHODS

We randomly assigned kidney-transplant recipients to a more-intensive belatacept regimen, a less-intensive belatacept regimen, or a cyclosporine regimen. Efficacy and safety outcomes for all patients who underwent randomization and transplantation were analyzed at year 7 (month 84).

RESULTS

A total of 666 participants were randomly assigned to a study group and underwent transplantation. Of the 660 patients who were treated, 153 of the 219 patients treated with the more-intensive belatacept regimen, 163 of the 226 treated with the less-intensive belatacept regimen, and 131 of the 215 treated with the cyclosporine regimen were followed for the full 84-month period; all available data were used in the analysis. A 43% reduction in the risk of death or graft loss was observed for both the more-intensive and the less-intensive belatacept regimens as compared with the cyclosporine regimen (hazard ratio with the more-intensive regimen, 0.57; 95% confidence interval [CI], 0.35 to 0.95; P=0.02; hazard ratio with the less-intensive regimen, 0.57; 95% CI, 0.35 to 0.94; P=0.02), with equal contributions from the lower rates of death and graft loss. The mean estimated glomerular filtration rate (eGFR) increased over the 7-year period with both belatacept regimens but declined with the cyclosporine regimen. The cumulative frequencies of serious adverse events at month 84 were similar across treatment groups.

CONCLUSIONS

Seven years after transplantation, patient and graft survival and the mean eGFR were significantly higher with belatacept (both the more-intensive regimen and the less-intensive regimen) than with cyclosporine. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00256750.).

The PROPKD Score: A New Algorithm to Predict Renal Survival in Autosomal Dominant Polycystic Kidney Disease

The course of autosomal dominant polycystic kidney disease (ADPKD) varies among individuals, with some reaching ESRD before 40 years of age and others never requiring RRT. In this study, we developed a prognostic model to predict renal outcomes in patients with ADPKD on the basis of genetic and clinical data. We conducted a cross-sectional study of 1341 patients from the Genkyst cohort and evaluated the influence of clinical and genetic factors on renal survival. Multivariate survival analysis identified four variables that were significantly associated with age at ESRD onset, and a scoring system from 0 to 9 was developed as follows: being male: 1 point; hypertension before 35 years of age: 2 points; first urologic event before 35 years of age: 2 points; PKD2 mutation: 0 points; nontruncating PKD1 mutation: 2 points; and truncating PKD1 mutation: 4 points. Three risk categories were subsequently defined as low risk (0-3 points), intermediate risk (4-6 points), and high risk (7-9 points) of progression to ESRD, with corresponding median ages for ESRD onset of 70.6, 56.9, and 49 years, respectively. Whereas a score ≤3 eliminates evolution to ESRD before 60 years of age with a negative predictive value of 81.4%, a score >6 forecasts ESRD onset before 60 years of age with a positive predictive value of 90.9%. This new prognostic score accurately predicts renal outcomes in patients with ADPKD and may enable the personalization of therapeutic management of ADPKD.

Conversion from everolimus with low-exposure cyclosporine to everolimus with mycophenolate sodium maintenance therapy in kidney transplant recipients: a randomized, open-label multicenter study

BACKGROUND

Data in kidney transplant recipients regarding elimination of calcineurin inhibitor (CNI) therapy from a de novo regimen based on low CNI exposure and an mTOR inhibitor are sparse, and restricted to CNI elimination within the first six months post-transplant.

MATERIAL/METHODS

In a 12-month, randomized, multicenter, open-label study, kidney transplant patients who had received everolimus, low-exposure cyclosporine and corticosteroids from transplantation to month 12 (with proteinuria <1 g/24 h at month 12) were randomized to convert from cyclosporine to mycophenolate sodium 720 mg/day with increased everolimus exposure (6-10 ng/mL [CNI-free group], n=15) or continue unchanged (everolimus 3-8 ng/mL [CNI group], n=15).

RESULTS

Median (range) baseline mGFR was 54 (21-87) mL/min and 37 (range 18-69) mL/min (p=0.053) in the CNI-free and CNI groups, respectively, compared to 56 (18-126) mL/min and 32 (12-63) mL/min at month 12 (p=0.007). The between-group difference in change in mGFR from baseline to month 12 post-conversion (the primary endpoint) was -14.4 mL/min (95% CI -29.3 to 0.6 mL/min, p=0.059 [least squares mean]). Changes in serum creatinine and estimated GFR to month 12 were significantly in favor of CNI-free patients. One CNI patient experienced biopsy-proven acute rejection. Study drug was discontinued due to adverse events in one CNI-free patient (7%) and three CNI-treated patients (20.0%).

CONCLUSIONS

Elimination of CNI from a de novo regimen of everolimus with low-exposure CNI at one year post-transplant maintained efficacy and led to a non-significant but clinically relevant improvement in renal function, although patients numbers were low (n=30). Findings from this small study require confirmation in a larger controlled trial.

Efficacy and safety of de novo or early everolimus with low cyclosporine in deceased-donor kidney transplant recipients at specified risk of delayed graft function: 12-month results of a randomized, multicenter trial

Immediate or early use of proliferation signal inhibitor (PSI)/mammalian target of rapamycin (mTOR) inhibitor therapy can avoid high exposure to calcineurin inhibitors but concerns exist relating to the risk of delayed graft function (DGF) and impaired wound healing with the mTOR sirolimus. CALLISTO was a 12-month, prospective, multicenter, open-label study. Deceased-donor kidney transplant patients at protocol-specified risk of DGF were randomized to start everolimus on day 1 (immediate everolimus, IE; n = 65) or week 5 (delayed everolimus, DE; n = 74). Incidence of the primary endpoint (biopsy-proven acute rejection, BPAR; graft loss, death, DGF, wound healing complications related to transplant surgery or loss to follow-up) was 64.6% and 66.2% in the IE and DE groups, respectively, at month 12 (P = 0.860). The overall incidence of BPAR was 20.1%. Median estimated glomerular filtration rate was 48 ml/min/1.73 m(2) and 49 ml/min/1.73 m(2) in the IE and DE groups, respectively, at month 12. DGF and wound healing complications were similar between groups. Adverse events led to study drug discontinuation in 17 IE patients (26.2%) and 28 DE patients (37.8%) (NS). In conclusion, introduction of everolimus immediately or early posttransplant in DGF-risk patients is associated with good efficacy, renal function and safety profile. There seems no benefit in delaying initiation of everolimus.

Toxoplasmosis-associated hemophagocytic syndrome in renal transplantation

Toxoplasmosis is an infrequent, often difficult to diagnose and potentially lethal disease in kidney transplant recipients. Among reported cases, a few were associated with hemophagocytic syndrome (HPS), a rare condition characterized by widespread proliferation of macrophages phagocytizing blood elements, accompanied by fever and pancytopenia. We report here the case of a patient who received a Toxoplasma gondii positive kidney allograft and developed invasive toxoplasmosis 10 days after surgery, with high fever, skin rash, arthralgias, and renal failure, followed by pneumonia, anemia, thrombocytopenia, liver dysfunction, and encephalitis. Mislead by the absence of Toxoplasma on blood smears, alveolar fluid, renal graft biopsy, and negative brain computed tomography, confusion with serum sickness, and simultaneous herpetic infection, we failed to make the right diagnosis and the patient died with septic shock 11 days later. An HPS was revealed by a late bone marrow analysis. This may well be the fourth case ever reported of toxoplasmosis-associated HPS in renal transplant recipients.

Zygomycosis caused by Cunninghamella bertholletiae in a kidney transplant recipient

Infections caused by Cunninghamella bertholletiae are rare but severe. Only 32 cases have been reported as yet, but in 26 of these this species was a contributing cause of the death of the patient. This opportunistic mould in the order Mucorales infects immunocompromized patients suffering from haematological malignancies or diabetes mellitus, as well as solid organ transplant patients. The lung is the organ most often involved. Two cases of primary cutaneous infection have been previously reported subsequent to soft-tissue injuries. We report a case of primary cutaneous C. bertholletiae zygomycosis in a 54-year-old, insulin-dependent diabetic man who was treated with tacrolimus and steroids after kidney transplantation. No extracutaneous involvement was found. In this patient, the infection may have been related to insulin injections. The patient recovered after an early surgical excision of the lesion and daily administration of itraconazole for 2 months. This case emphasizes the importance of an early diagnosis of cutaneous zygomycosis, which often presents as necrotic-looking lesions. Prompt institution of antifungal therapy and rapid surgical intervention are necessary to improve the prospects of patients who have contracted these potentially severe infections.

[Systemic embolism in a renal transplant patient. Echocardiographic demonstration of bronchial carcinoma with intracardiac invasion]

A 45 year old female renal transplant patient was admitted for subacute ischaemia of a lower limb. Echocardiography was performed and showed the presence of bronchial carcinoma with intracardiac invasion. The tumour was confirmed by thoracic computerised tomography and by bronchoscopy. Histological investigation of bronchial biopsies and of the arterial embolism extracted at surgery showed large cell malignant disease. The tumour partially responded to chemotherapy and the patient survived for 5 months. Extension of a bronchial carcinoma to the left atrium is a classical complication in autopsy reports but rarely a source of systemic embolism. Echocardiographic diagnosis of this condition is very rare. The incidence of malignant diseases is higher in renal transplant patients than in the general population but this has not been verified for bronchial carcinoma. Echocardiography played an essential role in this case, detecting the tumour and its extension, indicating a poor prognosis and guiding treatment.

Nephrogenic adenoma of the bladder in renal transplant recipients: a report of 9 cases with assessment of deoxyribonucleic acid ploidy and long-term followup

PURPOSE

We evaluated the outcome of nephrogenic adenoma, a benign tumor rarely encountered in renal transplant recipients.

MATERIALS AND METHODS

Between 1985 and 1993, 9 renal transplant recipients with a nephrogenic bladder adenoma removed by endoscopic resection were followed for 24 to 88 months (mean 40). Tumor deoxyribonucleic acid ploidy was assessed by flow cytometry at diagnosis and/or relapse.

RESULTS

The relapse rate was 88%. The tumors were diploid and of low proliferating potential, and showed no malignant transformation.

CONCLUSIONS

Our study confirms the lack of premalignant potential of nephrogenic adenomas. However, since transplant recipients might be at increased risk for bladder cancer, they should be followed closely.

Lack of effect of isradipine on cyclosporin pharmacokinetics

The influence of isradipine as a long acting form (IcazR LP 5 mg) on cyclosporin pharmacokinetics was studied in six hypertensive renal transplant patients (mean age 37 yrs; mean body weight 62 kg). These patients received a mean daily cyclosporin dose of 307 mg in two equal intakes. Isradipine was orally administered once a day at a dose of 5 mg before the morning cyclosporin intake. Cyclosporin kinetics was assessed over a 0-12-h period, the day before (D-1) and 13 days (D+13) after isradipine treatment. Whole blood concentrations of cyclosporin were determined by radioimmunoassay (RIA) using the SandimmuneR-RIA kit (specific and non-specific monoclonal antibodies). Area under the blood concentration-time curve (AUC), the maximum blood concentration (Cmax) and the time to reach Cmax (Tmax) on D-1 and D+13 were not significantly different whatever the specificity of the RIA method. For example, the mean AUC +/- sd values were 5,247 +/- 2,255 (D-1) vs 5,317 +/- 1,675 (D+13) microgram.1(-1).h for the specific and 20,905 +/- 8,317 vs 19,327 +/- 5,758 microgram.1(-1).h for the non-specific determinations. Therefore, the pharmacokinetics of cyclosporin is not influenced by co-administration of isradipine at a therapeutic dosage. Moreover, the clinical results show that isradipine treatment was effective after 13 days administration (mean systolic blood pressure 132 vs 158 mm Hg, P < 0.05 and mean diastolic blood pressure 77 vs 93 mm Hg, P < 0.05 in supine position), and well tolerated throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of radiologic lesions of rheumatoid polyarthritis in function of the presence or the absence of the rheumatoid factor IgA]

The authors compared, with the help of five radiological indices bearing on part (hand and wrists) or the all the articulations of the limbs concerned by rheumatoid arthritis (RA), a group of 45 RA with rheumatoid factor IgA (RF IgA) with a group of 45 RA without RF IgA by matching them according to age, sex and duration of evolution. They did not find any significant difference between the two groups for any of the indices. Although they are more often associated with agglutinant RF IgM, the RA with RF IgA are not more severe on the radiological level than the RA without FR IgA.