Exposure–effect relationship of mycophenolic acid and prednisolone in adult patients with lupus nephritis

Aims

The aim was to examine relationships between total and unbound mycophenolic acid (MPA) and prednisolone exposure and clinical outcomes in patients with lupus nephritis.

Methods

Six blood samples were drawn pre- and at 1, 2, 4, 6 and 8 h post-dose and total and unbound MPA and prednisolone pre-dose (C₀), maximum concentration (C_max) and area under the concentration–time curve (AUC) were determined using non-compartmental analysis in 25 patients. The analyses evaluated drug exposures in relation to treatment response since starting MPA and drug-related adverse events.

Results

Dose-normalized AUC varied 10-, 8-, 7- and 19-fold for total MPA, unbound MPA, total prednisolone and unbound prednisolone, respectively. Median values (95% CI) of total MPA AUC(0,8 h) (21.5 [15.0, 42.0] vs. 11.2 [4.8, 30.0] mg l^–1 h, P= 0.048) and C_max (11.9 [6.7, 26.3] vs. 6.1 [1.6, 9.2] mg l^–1, P = 0.016) were significantly higher in responders than non-responders. Anaemia was significantly associated with higher total (37.8 [14.1, 77.5] vs. 18.5 [11.7, 32.7] mg l^–1 h, P = 0.038) and unbound MPA AUC(0,12 h) (751 [214, 830] vs. 227 [151, 389] mg l^–1 h, P = 0.004). Unbound prednisolone AUC(0,24 h) was significantly higher in patients with Cushingoid appearance (unbound: 1372 [1242, 1774] vs. 846 [528, 1049] nmol l^–1 h, P = 0.019) than in those without. Poorer treatment response was observed in patients with lowest tertile exposure to both total MPA and prednisolone as compared with patients with middle and higher tertile exposure (17% vs. 74%, P = 0.023).

Conclusions

This study suggests a potential role for therapeutic drug monitoring in individualizing immunosuppressant therapy in patients with lupus nephritis.     

Management of infant diarrhea with high-lactose probiotic-containing formula

To study the influence of high-lactose probiotic-containing formula on the course of acute diarrhea, an experiment using a randomized controlled clinical trial with patients having acute diarrhea for 3 days was conducted. One hundred patients were allocated into two groups that were comparable for age, sex, and nutritional status. The test group was administered high-lactose Bifidobacterium bifidum-containing formula, while the control group had no high-lactose probiotic until the end of the experiment. The degree of subsequent diarrhea and recovery were monitored in both groups. The results for the test and control groups were analyzed and compared using the chi-square test and Fisher exact test with a significance level (alpha) of 0.05. The study results revealed that there was no significant difference between the test and control groups (p>0.05) as well as at positive clinical test (13%) and positive floating test (65%). However, the patients receiving probiotic-containing formula had significantly less frequency of stools, when compared with the control group (p<0.05).     

Reversible airway obstruction in rheumatic mitral valve disease

Lung function was studied in 24 patients with advanced mitral stenosis scheduled for mitral valve replacement (MVR), and revealed an obstructive ventilatory pattern [rewording of this sentence OK] . Forty per cent of the patients had a forced expiratory volume in 1 s (FEV₁)<60% of that predicted in the preoperative period. Twenty-five per cent of those operated upon showed a similar pattern up to 110 weeks postoperatively. A blind study of the effect of placebo and β₂ agonist (salbutamol) inhalation was performed preoperatively and 6 months postoperatively, to evaluate the reversibility of airflow obstruction in these patients, flow volume curve and body plethysmographic measurement of airway resistance (Rex) and intrathoracic gas volume (VTG). Patients in the pre and postoperative period showed a significant difference between the placebo and the β₂ agonist responses for FEV₁, FEV₁ as percentage of FVC (FEV₁% FVC), peak expiratory flow rate (PEFR), flow rate of 50% of expiratory vital capacity ([¨max₅₀), Rex and VTG (P<0.001). We conclude that salbutamol inhalation improves obstructive impairment in patients with MVR pre- and postoperatively.     

Influence of quasispecies on virological responses and disease severity in patients with chronic hepatitis C

AIM： To elucidate the influence of quasispecies on virological response and disease severity in patients with chronic hepatitis C.
METHODS： Forty seven patients with hepatitis C [32 with chronic active hepatitis （CAH）, 9 with cirrhosis, and 6 with hepatocellular carcinoma （HCC）] were screened for the presence of quasispecies by single stranded conformational polymorphism （SSCP） analysis in the hypervariable region （HVR） and non-structural 5B （NS5B） viral genes of hepatitis C virus. The 41 patients excluding those with HCC were on therapy and followed up for a year with the determination of virological response and disease severity. Virus isolated from twenty three randomly selected patients （11 non-responders and 12 showing a sustained virological response） was sequenced for the assessment of mutations.
RESULTS： The occurrence of quasispecies was proportionately higher in patients with HCC and cirrhosis than in those with CAH, revealing a significant correlation between the molecular evolution of quasispecies and the severity of disease in patients with hepatitis C. The occurrence of complex quasispecies has a significant association （P 〈 0.05） with the non-responders, and leads to persistence of infection. Significant differences （P 〈 0.05） in viral load （log10 IU/mL） were observed among patients infected with complex quasispecies （CQS）, those infected with simple quasispecies （SQS） and those with no quasispecies （NQS）, after 12 wk （CQS-5.2 ± 2.3, SQS-3.2 ± 1.9, NQS-2.8 ± 2.4） and 24 wk （CQS-3.9 ± 2.2, SQS-3.0 ± 2.2, NQS-2.1 ± 2.3） in the HVR region. However, a statistically significant difference （P 〈 0.05） was observed between the viral loads of patients infected with CQS and those infected with NQS in NS5B viral gene after 24 wk （CQS-3.9 ± 2.2, SQS-3.0 ± 2.2, and NQS-2.1 ± 2.3） and 48 wk （CQS-3.1 ± 2.7, SQS-2.3 ± 2.4, NQS-2.0 ± 2.3） of therapy. Disease severity was significantly associated with viral load during th