PRACTICAL EVALUATION OF THE FIGLU TEST IN PREGNANCY WITH SPECIAL REFERENCE TO THE WHITE CELL CHANGES

Using slight modifications to the method of Kohn, Mollin, and Rosenbach (1961) the histidine loading test has been carried out in 210 pregnant women. Seventy per cent. of the cases showed complete haematological correlation and this rose to 87% when marrow puncture was performed. False positive results occurred in some cases showing active erythropoiesis in response to iron therapy. False negative results were noted when other complications in addition to anaemia were present, and it was felt that these might interfere with the metabolism of histidine. In some cases the histidine test anticipated the haematological change.Seventy-seven per cent. of women with multiple pregnancies showed evidence of folic acid deficiency. Only in a few cases was the test positive before the 25th week of pregnancy. These were either cases of multiple pregnancy, haemolytic anaemia, malabsorption syndrome, or women with a recent history of megaloblastic anaemia of pregnancy. The test appears to confirm the significance of white cell changes as an indication of folic acid deficiency in pregnancy.

FOLIC ACID AND VITAMIN B12 LEVELS IN PREGNANCY AND THEIR RELATION TO MEGALOBLASTIC ANAEMIA

There is a significant fall in the serum folic acid level during pregnancy, reaching its lowest level at term. This is most pronounced in twin pregnancies. A similar but less spectacular fall occurs in the vitamin B(12) concentration. In megaloblastic anaemia both folic acid and vitamin B(12) levels are lower than in other pregnant women. The degree of megaloblastic change in the bone marrow, as measured by the type and number of megaloblasts, is reflected in the vitamin levels, cases with florid megaloblastosis showing the most marked depression of vitamin B(12) and folic acid activity. Although there is a significant difference in the mean folic acid levels between megaloblastic and normoblastic pregnant women, a considerable overlap exists between individual values in the two groups. When the labile folic-acid factor is determined separately the test becomes much more specific. In the present series, all cases of megaloblastic anaemia yielded labile-factor levels below 1.0 mmug. per ml., while a similar value was encountered in only one of 35 normal pregnancies. In five women with megaloblastic anaemia the vitamin B(12) concentration was less than 100 mumug. per ml. but rose to normal levels on folic acid therapy alone.

MICROBIOLOGICAL ASSAY OF FOLIC ACID ACTIVITY IN HUMAN SERUM

A method is described for the microbiological assay of folic acid activity in serum with Lactobacillus casei as test organism and a modified medium in which the organism gives a greater growth response than in media previously detailed. The results of experiments carried out to validate the use of this medium are shown. In 94 control subjects levels of folic acid activity in the serum ranged from 2. to 28 mmug./ml. (mean 7.8). The values in nine out of 10 patients with megaloblastic anaemia due to deficiency of folic acid were 1.0 mmug./ml. or less and one result was 2.0 mmug./ml. In six patients with megaloblastic anaemia associated with pregnancy the results ranged from 0.7 to 4.0 mmug./ml., and in untreated pernicious anaemia 28 out of 31 results were within or above the control range and three values were just below the lower limit of normal.

THE DIRECT ANTIGLOBULIN (COOMBS) TEST IN MEGALOBLASTIC ANAEMIA

Folic acid deficiency with the picture of a megaloblastic bone marrow may develop in haemolytic anaemia, and, on the other hand, both vitamin B(12) and folic acid deficiency may produce signs of haemolysis. As the correct interpretation of a positive antiglobulin reaction associated with megaloblastic erythropoiesis is particularly important, the effect of deficiency of vitamin B(12) and folic acid on the results of the test was investigated in 32 patients with vitamin B(12) or folic acid deficiency and a positive antiglobulin reaction was obtained in ten. There was no correlation between the result of the test and the degree of anaemia, and there was no significant difference between the incidence of positive results associated with deficiency of vitamin B(12) or folic acid. In determining the significance of a positive result, the time interval before agglutination occurs is sometimes of greater value than the strength of the reaction or the result of the gamma globulin neutralization test.

ESTIMATION OF SERUM L. CASEI ACTIVITY

Measurement of the serum Lactobacillus casei (;folic-acid') activity is widely used as an index of folic-acid deficiency. Present methods of assay result in recovery of about half the active material in normal serum. A modified method of assay is described which gives higher L. casei values and a clearer distinction between the sera of normal subjects and of patients with folic-acid deficiency.

THE URINARY EXCRETION AND TISSUE RETENTION OF CYANOCOBALAMIN BY SUBJECTS GIVEN REPEATED PARENTERAL DOSES

The urinary excretion of injected cyanocobalamin was studied in 30 previously untreated vitamin B(12)-deficient patients by measuring the urinary radioactivity after repeated injections of (58)Co vitamin B(12). The dose range used was 54 to 30,000 mug., each patient receiving the same dose at each injection. The results show that there is no constant trend to the excretion of greater or smaller proportions of the amount injected. It is also shown that there is a wide variation in the amounts excreted by each individual and between individual patients and that the capacity of the tissues to retain injected cyanocobalamin is very great, the amounts retained often being greatly in excess of the normal body stores. The excretion of radioactivity after parenteral infections of (58)Co vitamin B(12) was usually complete within 24 hours but exceptions to this were seen. The significance and value of the results is discussed.

PERNICIOUS ANAEMIA AUTOANTIBODY TO GASTRIC PARIETAL CELLS: IMMUNOFLUORESCENCE TEST WITH RAT STOMACH

Rat stomach provided an excellent substrate for immunofluorescence testing of gastric parietal cell autoantibodies in 65 human sera. The results of similar tests using human stomach corresponded closely in the 42 cases examined. The rat stomach had some advantage over human stomach in its ready availability in the fresh state, its occasional brighter staining reactions, and its avoidance of non-specific staining by the sandwich immunofluorescence technique.

LIPID COMPOSITION OF HUMAN BONE MARROW

1. A modified method for the analysis of phospholipid mixtures by selective hydrolysis is described. 2. The phospholipid compositions of normal human bone marrow and of the bone marrows of patients who died with anaemia or various forms of leukaemia were investigated. 3. Phospholipids from normal bone marrow comprised about 44% of lecithin, 4% of choline plasmalogen, 7% of glyceryl ether phospholipid (choline base), 10% of sphingomyelin, 22% of phosphatidylethanolamine plus phosphatidylserine, 8% of ethanolamine plasmalogen and 5% of glyceryl ether phospholipid (ethanolamine base). 4. The proportion of kephalin (i.e. phosphatidylethanolamine plus phosphatidylserine) in the pathological bone marrows tended to be lower than normal. No other consistent differences were observed between the normal and pathological samples. 4. A ceramide dihexoside was isolated from normal bone marrow.

DIAGNOSTIC VALUE OF SERUM HAPTOGLOBIN

Serum haptoglobin has been estimated quantitatively in 25 patients with haemolytic disease, and its diagnostic value assessed by comparing the levels with those obtained in 110normal subjects, in 149 patients with other forms of anaemia, and in 37 patients with non-haematological disorders. The normal range was found to be 33 to 213 mg./100 ml.; subnormal levels were found in 80% of patients with haemolytic disease or megaloblastic anaemia, patients with haemorrhage into the tissues, and occasionally in association with other diseases. When taken in conjunction with other clinical and laboratory features this simple biochemical estimation can be of diagnostic value.

SERUM PEPSINOGEN IN THE DIFFERENTIATION OF MEGALOBLASTIC ANAEMIA

Serum pepsinogen levels have been compared in 40 patients with severe megaloblastic anaemia with those obtained from 62 normal subjects, and with levels in 20 patients with pernicious anaemia in remission, 46 patients with iron-deficiency anaemia, and 18 patients with a duodenal ulcer. The range in the normal subjects was 55 to 482 units per ml. It is suggested that a level of below 90 units per ml. should be regarded as indicative of gastric atrophy. It was found to be of value in the early differential diagnosis of severe megaloblastic anaemia. The estimation was found to be reproducible and can be carried out in a routine hospital laboratory.