Overexpression of MRP1/ABCC1, Survivin and BCRP/ABCC2 Predicts the Resistance of Diffuse Large B-Cell Lymphoma to R-CHOP Treatment

BACKGROUND

Approximately 40% of patients with diffuse large B-cell lymphoma (DLBCL) experience treatment resistance to the first-line R-CHOP regimen. ATP binding cassette (ABC) transporters and survivin might play a role in multidrug resistance (MDR) in various tumors. The aim was to investigate if the coexpression of ABC transporters and survivin was associated with R-CHOP treatment response.

METHODS

The expression of Bcl-2, survivin, P-glycoprotein/ABCB1, MRP1/ABCC1, and BCRP/ABCC2 was analyzed using immunohistochemistry in tumor specimens obtained from patients with DLBCL, and classified according to the treatment response as Remission, Relapsed, and (primary) Refractory groups. All patients received R-CHOP or equivalent treatment.

RESULTS

Bcl-2 was in strong positive correlation with clinical parameters and all biomarkers except P-gp/ABCB1. The overexpression of MRP1/ABCC1, survivin, and BCRP/ABCC2 presented as high immunoreactive scores (IRSs) was detected in the Refractory and Relapsed groups (p < 0.05 vs. Remission), respectively, whereas the IRS of P-gp/ABCB1 was low. Significant correlations were found among either MRP1/ABCC1 and survivin or BCRP/ABCC2 in the Refractory and Relapsed groups, respectively. In multiple linear regression analysis, ECOG status along with MRP1/ABCC1 or survivin and BRCP/ABCG2 was significantly associated with the prediction of the R-CHOP treatment response.

CONCLUSIONS

DLBCL might harbor certain molecular signatures such as MRP1/ABCC1, survivin, and BCRP/ABCC2 overexpression that can predict resistance to R-CHOP.

Severe hyperkalemia induced by propranolol

INTRODUCTION

Hyperkalemia secondary to beta-adrenergic receptor blockade occurs in 1-5% of patients and is likely to develop with non-cardio-selective beta-blockers.

CASE REPORT

We have described hyperkalemia in a patient with angina pectoris receiving propranolol, clinically manifested as weakness, tightness behind the sternum and numbness in the limbs. Laboratory tests showed hyperkalemia (6.6 mmol/L), peaked T wave and a corrected QT interval of 510 ms. After discontinuation of propranolol, decline in potassium level, normalisation of electrocardiographic changes and clinical improvement were achieved. Causal relationship of drug related hyperkalemia has been confirmed as probable/likely according to Naranjo Adverse Drug Reaction Probability Score of 7 and the World Health Organization Uppsala Monitoring Centre Probability Scale.

CONCLUSION

Hyperkalemia can be unpredictable and life-threatening complication of propranolol or a non-selective adrenergic beta blocker treatment, and requires timely identification of cause and implementation of therapeutic measures.

Oral antibiotic prescription in ambulatory care in 1999--a contribution to the development of methods for drug consumption and prescription surveillance monitoring

The aim of the study was to estimate the consumption of antibiotic in ambulatory care. Oral antibiotic consumption in 1999 was analyzed in four pharmacies in the Zagreb area. The use of oral antibiotics in comparison with total drug consumption, the share of individual subclasses of oral antibiotics and the respective shares of individual products were also analyzed. The results obtained were expressed in terms of both the defined daily doses (DDD) and US$, and were compared with available national and international data. The study demonstrated a high share of oral antibiotics in the overall drug consumption, especially of newer and more expensive agents within individual subclasses of antibiotics. Further research is required to assess the rationale of such prescribing practices, especially in view of the current financial pressure on the Croatian health care system.

[Hyposensitization and antihistamines in the treatment of bronchial and allergic rhinitis]

The control of symptoms in patients with allergic rhinitis and bronchial asthma can not be always attained with hyposensitization. This may be achieved with more success with additional treatment with H1 antagonists of histamine receptors. By hyposensitization statistically significant decrease of the total IgE was achieved. Contrary to this, in cases in which the symptoms could not be controlled with hyposensitization, only antihistamines were additionally administered, no significant decrease of IgE took place. These were, probably, more severe cases in which the symptoms could not be controlled with the hyposensitization only. No significant effect on the values of blood eosinophiles was registered with hyposensitization or additional administration of antihistamines.