Objective:

To determine the cytogenetic damages generated by the use of methotrexate for the treatment of rheumatoid arthritis.

Methods:

Our experience in the use of methotrexate for cell synchronization as a retarder of the “S” phase cell cycle and its subsequent inhibition by competition with bromodeoxyuridine in obtaining chromosomes with “R” bands of replication, induced us to perform this cytogenetic study using peripheral blood lymphocytes cultured in PB-Max medium for 72 hours, from a 46-year-old patient, with a medical diagnosis of rheumatoid arthritis, treated with methotrexate for one month.

Results:

Clinically the patient presented inflammation articulations of left hand fingers and left shoulder, with impediment flex of the annular finger right hand, besides she has pain that prevent the movement of the same articulations, in occasions and because of this problem she cannot get up without help.

The conventionally cytogenetic analysis, shows that of the 50 analyzed cells, 23 (46%) presents normal karyotype; 17 (34%) presents aneuploidies of the chromosomic different groups including de (X) chromosome, and 10 (20%) of abnormal polymorphonuclear.

We discuss the genetic etiology of the biology cellular control, keep in mind that mentioned findings are preferentially directed due to aberrant cycles of centrosome duplication and mitotic spindle in general, as well as the partial disturbance of the ADN and ARN synthesis, probably caused by methotrexate action, this fact that is reflected in the aneuploidy findings in the karyotype are to random, without compromise of any particular chromosome of the determined group.

Conclusions:

It is suggested to the treating doctor should really take implement some rule in the therapeutic protocol of corresponding management, relationed with the chronicity and cytogenetic monitoring during the treatment with this medicine.

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