FOLIC-ACID DEFICIENCY AND MEGALOBLASTIC ERYTHROPOIESIS IN MYELOFIBROSIS

Myeloid neoplasms in the guise of nutritional deficiency

The classic BCR-ABL-negative myeloproliferative neoplasms (MPNs) which include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) are among the most frequent hematologic neoplasms. Because of their relatively smooth clinical course, it is likely that many of these MPNs actually go undetected. Considering the high prevalence of iron, folic-acid, and vitamin B₁₂ deficiencies in developing countries, their coexistence with MPN can be expected frequently. In such situations where both disorders coexist, MPN is often overlooked. This causes considerable diagnostic delay. In this paper, two cases of PMF and one case of PV where the diagnosis of MPN was delayed for about 3 years are discussed. Presence of concomitant vitamin B₁₂, folate, and iron deficiencies perhaps camouflaged the underlying MPN. Bearing in mind the possibility of MPN, even in the setting of apparent nutritional deficiency and performing a bone marrow evaluation, is the crucial step in unveiling the hidden MPN.

DETECTION OF FORMIMINO-GLUTAMIC AND UROCANIC ACIDS IN URINE BY MEANS OF THIN-LAYER CHROMATOGRAPHY

A simple and rapid method has been developed for the simultaneous separation and semi-quantitative estimation of formimino-glutamic and urocanic acids in urine. The urinary excretion of these compounds in a group of normal subjects and in a number of illustrative cases has been determined. In view of current opinion that it is the total of these two metabolites of histidine which is the significant figure in clinical investigation, their simultaneous separation and measurement is an important advantage of the method.

Response to pyridoxine hydrochloride in refractory anemia due to myelofibrosis

Eleven of 14 patients with primary myelofibrosis were given a therapeutic trial with 250 mg of pyridoxine hydrochloride daily because of refractory anemia. The effect on the hemoglobin level and the hematocrit value was studied and compared to that in a group of untreated patients with the same degree of anemia. Six of 11 treated patients responded within three months with a rise in the hemoglobin level (at least 3 g/100 ml) and/or an increase in the hematocrit value (at least 10 per cent), and transfusions were no longer required. Deliberate discontinuation of pyridoxine treatment in one responding patient was followed by a relapse of the anemia; resumption of therapy once again induced an erythropoietic response. Spontaneous remissions of anemia were not observed in the untreated group. It is concluded that a trial with pyridoxine is warranted in patients with myelofibrosis and refractory anemia.

Folate Activity in Malignant Blood Diseases

Basal serum folate activity, serum folate clearance and folate output in the urine after folic acid loading, urocanic acid and formiminoglutamic acid output in the urine after histidine loading were determined on 27 patients with malignant blood diseases in therapeutic remission. The mean values for basal serum folate activity and for serum folate activity and urinary folate output after folic acid loading were significantly lower than normal, both in chronic myeloid leukemia and in Hodgkin's disease. On the contrary, in chronic lymphatic leukemia only after folic acid loading urinary folate output was significantly lower than normal. The median values for urinary excretion of histidine derivatives after histidine loading was higher than normal in Hodgkin's disease and in chronic lymphatic leukemia. Folate deficiency was observed in 16 out of the 27 patients under study. Comparative analysis of multiple test results showed different response patterns which can be attributed to different types of deficiency, namely tetrahydrofolate deficiency from primary folate deficiency and possibly tetrahydrofolate deficiency from folate metabolic abnormalities. Folate deficiency appeared to correlate with the activity of disease when expressed by such parameters as performance status and erythrocyte sedimentation rate. This applies to all patients as a group, and, as far as performance status is concerned, to the chronic lymphatic leukemia patients as a subgroup. Folate deficiency did not appear to correlate with other parameters of disease nor to induce, in the majority of patients, the typical hematologic features. Folate deficiency in malignant blood diseases is likely to be somehow related to the abnormal cell proliferation, through several possible mechanisms which are analysed and discussed.