J. H. Dagg

Value of Erythrocyte Protoporphyrin in the Diagnosis of Latent Iron Deficiency (Sideropenia)

THE erythrocyte content of free protoporphyrin does not normally exceed 40 p g . per IOO ml. erythrocytes (Cartwright, Huguley, Ashenbrucker, Fay and Wintrobe, 1948). In iron-deficiency anaemia, this level is greatly increased (Pagliardi, Prato, Giangrandi and Fiorina, 1959 ; Prato and Mazza, 1962; Heilmeyer and Clotten, 1962). Levels of erythrocyte protoporphyrin have not previously been studied in latent iron deficiency. Sideropenia is a term which refers to the stage of iron deficiency before frank anaemia has developed. Such sideropenic patients may be defined as those having haemoglobin levels between 12 and 13 g. per 100 ml., a saturation of the total iron-binding capacity less than 16 per cent, and an absence of stainable iron in the bone marrow. It is recognized that the tissue changes associated with iron deficienqsuch as atrophc glossitis, cheilosis and dysphagia, may occur before anaemia has developed (Waldenstrom, 193 8), and more recently Beutler, Larsh and Gurney (1960) have attributed such non-specific symptoms in women as chronic fatigue and ‘neurasthenia’ to tissue iron deficiency without anaemia. It would clearly be of value, in investigation of the sideropenic state, to have a reliable but simple means of confirming the presence of latent iron deficiency which would avoid the necessity for bone-marrow biopsy. The final step in the biosynthesis of haem involves the incorporation of iron into protoporphyrin and it was considered that the erythrocyte protoporphyrin level might be a sensitive index of early iron deficiency in the red cell. A study of free erythrocyte protoporphyrin levels has therefore been carried out in normal subjects, and in patients with latent iron deficiency and frank iron-deficiency anaemia, to determine the usefulness of t h s measure as a diagnostic test for sideropenia.

Cytochrome Oxidase in Latent Iron Deficiency (Sideropenia)

THE tissue changes usually associated with iron-deficiency anaemia, such as atrophic glossitis, angular stomatitis and dysphagia, may occur during the stage of latent iron deficiency before anaemia has developed (Waldenstriim, 1938). More recently it has been suggested that nonspecific symptoms such as chronic fatigue, irritability and ‘neurosis’ in women may be due to tissue depletion of iron without accompanying anaemia (Beutler, Larsh and Gurney, 1960). A possible explanation for these manifestations is that certain iron-containing tissue enzymes, including catalase, cytochrome c, and cytochrome oxidase may be reduced in states of latent iron deficiency. Beutler (1957), Gubler, Cartwright and Wintrobe (1957) and Beutler and Blaisdell (1958) demonstrated a reduced content of cytochrome c in the organs of iron-deficient animals even when the blood haemoglobin was not greatly reduced. Using a histochemical technique, Jacobs (1961) has shown that the cytochrome-oxidase activity of buccal epithelium is reduced in some patients with frank iron-deficiency anaemia. It is of interest that one of Jacobs’s non-anaemic control subjects with absent cytochrome oxidase activity probably had latent iron deficiency (haemoglobin 13.3 g. per 100 ml.; serum iron 57 p g . per IOO ml. and total iron binding capacity 420 pg. per IOO ml.). For these reasons, an investigation has been carried out on the cytochrome-oxidase activity of buccal mucosal biopsy material from: (a) subjects with latent iron deficiency without anaemia, (b) patients with frank iron-deficiency anaemia, and (c) control subjects with normal iron stores.

Incidence of Iron Deficiency, with and without Anaemia, in Women in General Practice

The incidence of iron deficiency anaemia in 500 women in an urban general practice was found to be 8.2 per cent, 9.7 per cent in 402 ‘patients’ and 2 per cent in 98 symptomless volunteers (‘subjects’). Iron deficiency anaemia was diagnosed when the haemoglobin was less than 12 g. per 100 ml. and the saturation of the total iron binding capacity of the serum was less than 16 per cent.

The incidence and possible relevance of Bence‐Jones protein in the sera of patients with multiple myeloma

Summary We present results showing that the detectable incidence of Bence‐Jones protein in the sera of patients with multiple myeloma is equivalent to the highest detectable incidence of Bence‐Jones protein in highly concentrated urine when tested by immuno‐isoelectric focusing. In a series of 25 multiple myeloma patients, immuno‐isoelectric focusing showed the incidence of Bence‐Jones proteinaemia to be 68% compared with a detectable incidence of Bence‐Jones proteinuria of 32–64% by immunoelectrophoresis and immuno‐isoelectric focusing depending upon the urine concentration factor. In view of the variability of factors governing urinary Bence‐Jones protein levels, such as renal catabolism, reabsorption and losses during concentration, we suggest that monitoring of serum Bence‐Jones protein by immuno‐isoelectric focusing should be carried out in conjunction with measurements of urinary Bence‐Jones protein in multiple myeloma.

The incidence, clonal origin and secretory nature of serum paraproteins in chronic lymphocytic leukaemia

Summary. Immuno‐isoelectric focusing (IIEF) showed a 61% incidence of serum paraproteinaemia in 56 patients with chronic lymphocytic leukaemia (CLL). A strong correlation between the serum paraprotein heavy chain isotypes and those of the cytoplasmic heavy chain immunoglobulins was observed with no discrepancy noted in light chain expression. Density gradient ultracentrifuga‐tion analysis of selected sera containing monoclonal IgM showed that the IgM paraproteins were mostly 19S, secretory IgM but one patient was found to have both 19S and 8S monoclonal IgM. When the cellular origin of the IgM and IgD paraproteins found in one patient was investigated, both paraproteins were found to share the same idiotype and originate from the neoplastic clone.

Serum paraproteins in chronic lymphocytic leukaemia

The presence of paraproteins in the sera of 10 patients with chronic lymphocytic leukaemia (CLL) was investigated using immunoisoelectric focusing. Monoclonal immunoglobulins were found in nine of these 10 sera. Five sera contained a single monoclonal IgM paraprotein, one serum contained a single monoclonal IgG paraprotein, while three sera contained more than one monoclonal paraprotein--namely, IgM + IgD, IgM + IgG, and IgM + IgD + IgG. The results indicate that the malignant B cells of CLL may be at a later stage of differentiation than previously assumed and serum monoclonal immunoglobulin could be of value as a tumour marker.

A Direct Method of Determining Red Cell Lifespan Using Radioiron: An Application of the Occupancy Principle

Summary. Existing methods of measuring directly the lifespan of red cells are inconvenient or technically difficult. In the present study, plasma iron clearance and red cell utilization curves were followed after the intravenous injection of radioiron as for routine ferrokinetic measurements; chemical determinations of stable iron in plasma and red cells were also made. The mean red cell lifespan and the flow rate of iron into erythropoiesis were derived from these data by applying the occupancy principle (Orr & Gillespie, 1968).

Incidence of Gastric Parietal Cell Antibody in Families of Patients with Iron Deficiency Anaemia

There is an association of pernicious anaemia with iron deficiency anaemia (Faber and Gram, 1924). There is also a high incidence (85 per cent) of gastric parietal cell antibody in the sera of patients with pernicious anaemia (Taylor, Roitt, Doniach, Couchman and Shapland, 1962) and a less marked, but significantly increased incidence (33 per cent) in patients with iron deficiency anaemia who have a histamine fast achlorhydria (Dagg, Goldberg, Anderson, Beck and Gray, 1964). Pernicious anaemia has a familial incidence (Askey, 1940; Callender and Denborough, 1957) and there is also an increased frequency of achlorhydria in relatives of patients with pernicious anaemia (Askey, 1940; Neel, 1947). In addition te Velde, Abels, Anders, Arends, Hoedemaeker and Nieweg (1964) have found the gastric parietal cell antibody in 20 per cent of relatives of patients with pernicious anaemia, compared with 6 per cent in a control series. Because of the association of iron deficiency anaemia with pernicious anaemia and the increased incidence of histamine fast achlorhydria and parietal cell antibody in both diseases, the occurrence of the antibody has been assessed in the families of patients with iron deficiency anaemia, histamine fast achlorhydria and gastric parietal cell antibody.

The Assessment of Red Cell Survival in Normal Subjects and in Patients with Haemoly tic Disorders and Ineffective Erythropoiesis using the Radioiron Occupancy Method

A direct method for measuring red cell lifespan in vivo using the radioiron occupancy method (Dagg et al, 1972) has been applied to eight normal subjects. The mean red cell lifespan was 116 d with a range of 104‐124 d.