Serum 'Uracil+Uridine'Levels Before and After Vitamin B12 Therapy in Pernicious Anaemia

S ummary . The serum 'uracil+uridine'levels, expressed as uracil, have been measured in 10 cases of pernicious anaemia both before and after treatment, and compared with the levels in 97 normal subjects. The mean pre-treatment value (8.82 μmol/l., range 6.0–12.0 μmol/l.) differed significantly from that of the normal controls (15.7 μmol/l., range 5.7–40.5 μmol/1., t = 8.8, P <0.001). This confirms the low serum uracil level previously reported in pernicious anaemia in relapse. The level rose progressively after treatment, reaching a maximum on the fourth day (mean 17.85 μmol/1., range 9.3–23.4 μmol/l.). This was not significantly different from the mean of the normal control group. The difference between the pre- and post-treatment levels was significant on days 3, 4 and 5 ( P <0.005, P <0.001 and P <0.005 respectively) and the rise preceded the reticulocyte response by 24 h. A further case was treated with physiological doses of vitamin B₁₂ (2 μg daily for 6 d) and a similar rise in the serum uracil level noted.
These results are not explained by any of the known functions of vitamin B₁₂. They are, however, similar to the changes in the serum methionine levels previously reported in pernicious anaemia. The latter were readily explained by the known action of vitamin B₁₂ on ' de novo 'methionine synthesis and it is suggested that the synthesis of uracil, like that of methionine, might be influenced by vitamin B₁₂ in man.     

Serum Valine and Methionine Levels in Pernicious Anaemia under Treatment

The serum levels of the amino acids, valine and methionine have been determined by a quantitative microbiological method in 17 cases of pernicious anaemia both before and on successive days after treatment. The results have been compared with the serum levels of the two amino acids in 16 normal subjects under similar conditions.
The serum valine level is normal in pernicious anaemia in relapse. It falls sharply during the first 48 hours following treatment, thereafter rising gradually to reach about two-thirds the pretreatment level by the fifth day. This confirms the fall in valine level in whole blood and marrow previously reported in pernicious anaemia under treatment.
The serum methionine level is subnormal in pernicious anaemia in relapse. It rises to normal in 48 hours after treatment.
Both vitamin B₁₂ and folic acid are effective in lowering the serum valine and elevating the serum methionine.
The rise in serum methionine can be explained in terms of the known actions of vitamin B₁₂ and folic acid. The fall in serum valine cannot at present be explained but several possibilities are discussed.     

HL-A Groups in Pernicious Anaemia

S ummary . There is a significant association with HL-A₃ type and pernicious anaemia. In addition there is a negative association with HL-A₂. There is no association between HL-A type and the presence or absence of immunity to intrinsic factor.     

Nitrogen Metabolism in Pernicious Anaemia

S ummary . Nitrogen metabolism has been studied in pernicious anaemia patients before, during and after treatment with vitamin B₁₂ therapy. Before treatemnt there are high levels of amino acids and urea present in the urine while the creatinine level remains normal. At the same time there is a state of amino acidaemia, but adequate treatment brings about a rapid return of the plasma amino acid level to normal. The pattern of recovery appears to be quite different in the urine where an initial, but temporary, fall in the excretion of urea and amino acids to subnormal levels is followed by a slow return to normal on prolonged therapy. During this time the excretion of creatinine remains within the normal range.
Substiution of placebo for vitamin B₁₂ therapy brings about an early recurrence of the abnormal excretion of urea and amino acids, even before any sign of clinical deterioration occurs in the condition of the patient; creatinine excretion again remains normal.
The findings are in full agreement with the view that vitamin B₁₂ plays a fundamental and essential role in the general utilization of amino acids for protein biosynthesis in mammals.     

Pernicious Anaemia and Lymphoproliferative Disease

2 patients with associated lymphoproliferative disease and pernicious anaemia are described. The lymphocytes in each were characterized by surface marker studies. In 1 of the cases, therapy with vitamin B₁₂ appeared to accelerate the neoplastic growth.     

Erythroblast Kinetics in Pernicious Anaemia,Erythroleukaemia and Sideroblastic Anaemia

DNA synthesis time (Ts) and ³H-thymidine labelling index (TLI) of erythroblasts have been determined in 25 patients with various types of haematologic disorders using in vitro double labelling method. No remarkable differences in both Ts and TLI were noted between haematologically normal subjects and patients with increased effective erythropoiesis (haemolytic anaemias), suggesting that the cell cycle time is not principally altered under the augmented erythropoiesis. In pernicious anaemia, Ts of basophilic erythroblasts was significantly shortened and TLI was elevated above normal. Normalization of erythropoiesis by vitamin B₁₂ was associated with a transient increase of TLI in polychromatic erythroblasts, which was interpreted to reflect prevention of intramedullary premature death of basophilic megaloblasts. Erythroleukaemia showed a markedly prolonged Ts and lowered TLI indicating the presence of cells with prolonged cell cycle time. These findings contrasted to that of pernicious anaemia despite certain morphological as well as functional similarities. In idiopathic sideroblastic anaemia, prolongation of Ts was observed to a similar extent as erythroleukaemia, while TLI remained almost normal. In 2 cases with suspected erythroleukaemia presenting an intermediate clinical picture between erythroleukaemia and sideroblastic anaemia, Ts of basophilic erythroblasts was found to be prolonged along with modestly lowered TLI.     

Metabolism of 5-MethyItetrahydrofolate in Pernicious Anaemia

S ummary 5-Methyltetrahydropteroylglutamic acid was given intravenously to control subjects and to patients with untreated megaloblastic anaemia. The rate of clearance of this substance from the plasma and excretion into the urine after an intravenous dose of 5 μg./kg. of body weight was followed.
The rate of clearance was faster in patients with folate deficiency as compared to control subjects. In pernicious anaemia the clearance was either within the normal range or more rapid than normal if there was associated folate deficiency. No support was obtained for the hypothesis that in pernicious anaemia there is a failure to utilize 5-methylfolate.     

Iron Deficiency Activating Latent Pernicious Anaemia

A 48-year-old woman developed anaemia with evidence of both iron and vitamin B₁₂ deficiencies. These deficits were corrected following treatment with ferrous sulfate and ascorbic acid. Subsequently, she was found to have latent pernicious anaemia. It is suggested that iron deficiency may play a role in the development of vitamin B₁₂ deficiency in certain patients with latent pernicious anaemia.     

Pernicious Anaemia and Polycythaemia Rubra Vera

Forty patients with pernicious anaemia and polycythaemia vera have been described. In order to determine whether this association was due to an autoimmune mechanism or to chance, the frequency of parietal cell antibodies was estimated in 51 patients with polycythaemia. The incidence of parietal cell antibodies in these patients was similar (8 per cent) to that in a matched control group (6 per cent).     

Familial Autoimmune Haemolytic Anaemia Associated with Rheumatoid Arthritis and Pernicious Anaemia

S ummary . A family was studied in which one son, a daughter and a paternal aunt showed clinical and laboratory evidence of autoimmune haemolytic disease. The father has long-standing rheumatoid arthritis, another son has proven pernicious anaemia while one daughter, though clinically well, exhibits mild serological abnormality. Other clinically normal members of this family were also investigated. Anti-parietal cell antibodies were demonstrated in one case of autoimmune haemolytic disease in addition to being noted in the serum of the member with pernicious anaemia. The direct antiglobulin reaction was strongly positive in those affected by haemolytic disease, but in addition a weak positive reaction was demonstrated in the case of pernicious anaemia where eluate studies indicated the possibility of an antibody similar in nature to the one present in the haemolytic cases, rather than a non-specific reaction. The pattern of cold auto-antibodies, warm auto- and iso-antibodies and other abnormal serology found in the blood of different members of this family would appear to suggest a common hereditary basis for the diseases present.     

Pernicious Anaemia in Indian Immigrants in the London Area

Two out of 15 cases of megaloblastic anaemia in Punjabi immigrants in the Southall area of Middlesex, studied in one year, were found to have all the features of Addisonian pernicious anaemia. This unexpected finding in Asiatics calls for a reappraisal of the previously accepted rarity of this disease in dark-skinned races and draws attention to the need for consideration of pernicious anaemia as a cause of megaloblastic anaemia in the Indian immigrant.     

Antibody Activity against Hog Intrinsic Factor in Pernicious Anaemia

S ummary . The sera of 100 adult patients with Addisonian pernicious anaemia not previously exposed to hog intrinsic factor were tested for antibody activity against hog intrinsic factor by the charcoal method: 55 sera containing antibody to human intrinsic factor showed antibody activity against hog intrinsic factor; 45 sera had no demonstrable antibody activity against human or hog intrinsic factor. A high degree of cross reactivity between antibody to human intrinsic factor and hog intrinsic factor was thus demonstrated in vitro .
Hog intrinsic factor was equally effective in potentiating vitamin B₁₂ absorption to normal levels in pernicious anaemia patients with and without circulating antibody active against hog intrinsic factor. Antibody to intrinsic factor circulating in the blood was therefore considered to have no effect on hog intrinsic factor in the human gastrointestinal tract. The possibility of a direct effect of circulating antibodies on the production and/or release of endogenous intrinsic factor by the gastric mucosa could not be excluded.     

Co57 Vitamin B12 Clearance Studies in Pernicious Anaemia

• 1 Clearance rate of intravenously administered radioactive vitamin B₁₂ in untreated pernicious anaemia patients is slow in 50 per cent of cases studied.
• 2 Administration of labelled vitamin B₁₂ bound to slow serum to ‘normal clearing’ pernicious anaemia subjects or to normal persons is followed by normal clearance rate.
• 3 Radioactive vitamin B₁₂ bound to normal serum is cleared at a normal rate in pernicious anaemia patients with slow clearance rate.
• 4 Radioactive vitamin B₁₂ bound to slow serum when mixed with normal serum in proportions of 1:1 or 1:0.5 is cleared at a normal rate in ‘slow clearing’ pernicious anaemia patients.
• 5 These studies suggest the presence of a ‘serum factor’ in normal serum and some patients with pernicious anaemia in relapse which enhances clearance of vitamin B₁₂ bound to ‘slow serum’.

     

Abnormal Folate Polyglutamate Ratios in Untreated Pernicious Anaemia Corrected by Therapy

The relative amounts of folate compounds having 1–3-, 4–, 5– and 6–glutamic acid residues in the molecule were measured in red blood cells. The results were expressed in relation to methyltetrahydrofolate pentaglutamate (5-glutamic acid residues) which is the analogue present in highest concentration. When the concentration of pentaglutamate is given a value of 100 the relative concentration of folates with 1–3-, 4-, 5- and 6-glutamic acid residues in control subjects are 48, 48, 100 and 58 respectively.
In folate deficiency there is a fall in the relative amount of the short chain glutamic acid chain compounds in addition to having an overall fall in the amount of folate present, the values for 1–3, 4, 5 and 6 chain folates being 16, 14, 100 and 39. By contrast, in untreated pernicious anaemia there is an accumulation of the short chain folates as well as an overall fall in polyglutamate concentration and the relative concentrations were 72, 44, 100 and 30.
Folate polyglutamate appears to be the active coenzyme and the relative amounts of glutamic acid residues may serve to regulate the rate of enzyme activity. In pernicious anaemia the amount of enzyme is reduced and on this hypothesis the regulatory function impaired.     

Pernicious Anaemia in Association with Argyrophil (Sevier-Munger) Gastric Carcinoid

3 cases of pernicious anaemia in association with gastric carcinoid (in 1 case multiple) are described. All tumours were rich in argyrophil cells with the Sevier-Munger and Grimelius staining techniques, indicating that they might be of the enterochro-maffin-like cell type. The possible causal relationship between pernicious anaemia and this type of argyrophil carcinoid is discussed.