1191 PLASMA-IRON AND IRON-BINDING CAPACITY with Mr Sanderson (April 26, p. 988) that SIR,-Iagree we receive many unjustifiable requests to measure plasmairon and iron-binding capacity-for example, when irondeficiency anxmia is obvious from examination of the blood-film or when these tests are virtually useless for the diagnosis of anaemia, as in patients who have recently undergone surgery when both values are depressed. However, these measurements are often useful if evaluated with both the clinical and other laboratory findings, and with knowledge of the many factors which affect plasma-iron-for example, Diurnal the variation in relation to menstrual cycled2 variation, mentioned by Dr Eastham (May 10, p. 1090), is of less importance because it is reduced or even absent in patients with blood - disease.3 As Dr Hamblin has indicated (May 10, p. 1090), the main use of plasma-iron and iron-binding capacity is to distinguish between iron-deficiency anoemia and the anaemia of chronic disorders, without examination of the bone-marrow. When mild, the anxmia of iron deficiency may be normocytic and normochromic, even sometimes when the patient presents with tissue changes, such as angular cheilosis or hair loss. In contrast, the anaemia of chronic disorders, although usually normocytic and normo-
chromic,
may be
mildly microcytic and hypochromic. therefore, lead to
Reliance on red-cell indices alone may, avoidable errors. The
measurements
have other
important
uses:
(1) Thalassaemia minor may be suspected from the blood-film and mean corpuscular volume, &c., and in careful hands may usually be distinguished from iron deficiency by a discriminant function based on the haemoglobin concentration, red-cell count and M.c.v. obtained with reliably calibrated electronic counters.4 However, the discriminant function is not always reliable, particularly in anaemic pregnant women who may require urgent therapy. Such patients must not be given parenteral iron unless they are iron-deficient, and this will be excluded by a normal or increased plasma-iron which will prompt further appropriate investigation. (2) A low plasma-iron and normal or increased binding capacity may indicate iron deficiency when the usual blood changes are obscured by those of other blood disease with which iron deficiency may coexist-for example, cardiac haemolytic anaemia. (3) Hypochromic anaemia may result from other defects in haem synthesis as in the sideroblastic anxmias, and a normal or raised plasma-iron will indicate the need for bone-marrow examination. (4) Plasma-iron is a useful screening test for iron overload in patients with liver disease and/or diabetes. Medical Unit, London Hospital, London E1 1BB.
about only one point: on the very rare occasions which serum-iron is a useful estimation, iron-binding capacity (or transferrin levels) should be assayed as well. 6,77 Contrary to Dr Hamblin’s experience (May 10, p. 1090), we have found the simple haematological tests at least as useful as serum iron concentration and iron-binding capacity in the important differential diagnosis between iron" deficiency anaemia and the anaemia of chronic disorders " (in the latter the film is usually normochromic and normocytic,9 unless there is superimposed iron deficiency). They are also performed much more quickly and cheaply. son
on
Department of Chemical Pathology, Westminster Medical School, 17 Page Street, London SW1P 2AR.
PEPTIC ULCER
SIR It is a pity to discuss, as you did in your editorial of May 10 (p. 1074), two separate diseases, gastric and duodenal ulcer, under the conglomerate title, peptic ulcer. It is absurd to ignore the evidence for hereditary factors. These two diseases are inherited separately, the first-degree relatives of patients with duodenal ulcer having about three times the incidence of duodenal ulcer in a control population, and first-degree relatives of patients with gastric ulcer having about three times the incidence of gastric ulcer in a control population. 10, 11 Moreover, the Danish twin data suggest that genetic and environmental factors are about equal in importance in these diseases.12 Department of Surgery, Royal Postgraduate Medical School, London W12 0HS.
SIR,-I, too, have been campaigning for years against indiscriminate requests for serum iron and iron-binding capacity,5-7 and I should like to congratulate Mr Sanderson on his letter (April 26, p. 988). As he says, it is part of the much wider problem of uncritical investigation, which is always discouraged by pathologists for reasons some are explained half-jokingly by Dr Eastham in the last paragraph of his letter (May 10, p. 1090): the problem has also been discussed by us.8 I disagree with Mr Sandernot
of which
1. Beard, R. J., Brooke, B. N. Lancet, 1967, ii, 1113. 2. Zilva, J. F., Patston, V. M. ibid. 1966, i, 459. 3. Paterson, J. C. S., Marrack, D., Wiggins, H. S. J. clin. Path. 1953, 6, 105. 4. England, J. M., Fraser, P. M. Lancet, 1973, i, 449. 5. Zilva, J. F., Patston, V. J. ibid. 1966, i, 459. 6. Zilva, J. F. ibid. 1968, i, 636. 7. Zilva, J. F., Pannall, P. R. Clinical Chemistry in Diagnosis and Treatment; chapter xv. London, 1971. 8. Carter, P. M., Davison, A. J., Wickings, H. I., Zilva, J. F. Lancet, 1974, ii, 1555.
J. H. BARON.
OSTEITIS CONDENSANS ILII SIR,-The letter by Dr Richards and his colleagues (April 5, p. 812) raises some important issues on radionuclide imaging techniques as applied to bone. The 99m technetium-pyrophosphate method relies on the fact that pyrophosphate is incorporated into regions of bone associated with osteoblastic activity.13-15 In their letter, the McMaster investigators state: " The distribution of bloodflow in the sacro-iliac region was bilaterally symmetrical." The scintigraphic appearances immediately after injection of the radioactive material do reflect blood-pool, whereas a more proper reflection of bone reaction is obtained by of the appearances after a suitable (3-4 hours) delay.14,16 We have measured this delayed uptake of isomer in 7 patients with osteitis condensans ilii and have found it assessment
to
ADAM TURNBULL.
JOAN F. ZILVA.
be increased in 5. The appearances
-
conventionally recorded by scintiscanning require interpretation. It is important to remember that this interpretation is susceptible to the same subjective error as the interpretation of X-rays and that this difficulty is enhanced in patients with bilaterally symmetrical disease. The sacroiliac region is particularly difficultt to assess because of large bone mass and variation due to age. We have devised a technique which allows for precise measurement of the intensity of isomer uptake in the region of the sacroiliac joints in relation to the sacrum. 17 Using Gruchy, G. C. Clinical Hæmatology in Medical Practice; chapter VI. Oxford, 1970. 10. Doll, R., Buch, J. Ann. Eugen. 1950, 15, 135. 11. Doll, R., Kellock, T. D. ibid. 1951, 16, 231. 12. Jensen, K. G. Peptic Ulcer: Genetic and Epidemiological Aspects 9. de
based on Twin Studies. Copenhagen, 1972. 13. Bland, W. H. Nuclear Medicine; p. 454. New York, 1971. 14. Weber, D. A., Greenberg, E. J., Dimich, A., Kenny, P. J., Rothschild E. O. J. nucl. Med. 1969, 10, 9. 15. Kaye, M., Silverton, S., Rosenthall, L. ibid. 1975, 16, 40. 16. Genant, H. K., Bautovich, G. J., Singh, M., Lathrop, K. A., Harper, P. V. Radiology, 1974, 113, 373. 17. Russell, A. S., Lentle, B. C., Percy, J. S. J. Rheumatol. (in the
press).
chromic,
may be
mildly microcytic and hypochromic. therefore, lead to
Reliance on red-cell indices alone may, avoidable errors. The
measurements
have other
important
uses:
(1) Thalassaemia minor may be suspected from the blood-film and mean corpuscular volume, &c., and in careful hands may usually be distinguished from iron deficiency by a discriminant function based on the haemoglobin concentration, red-cell count and M.c.v. obtained with reliably calibrated electronic counters.4 However, the discriminant function is not always reliable, particularly in anaemic pregnant women who may require urgent therapy. Such patients must not be given parenteral iron unless they are iron-deficient, and this will be excluded by a normal or increased plasma-iron which will prompt further appropriate investigation. (2) A low plasma-iron and normal or increased binding capacity may indicate iron deficiency when the usual blood changes are obscured by those of other blood disease with which iron deficiency may coexist-for example, cardiac haemolytic anaemia. (3) Hypochromic anaemia may result from other defects in haem synthesis as in the sideroblastic anxmias, and a normal or raised plasma-iron will indicate the need for bone-marrow examination. (4) Plasma-iron is a useful screening test for iron overload in patients with liver disease and/or diabetes. Medical Unit, London Hospital, London E1 1BB.
about only one point: on the very rare occasions which serum-iron is a useful estimation, iron-binding capacity (or transferrin levels) should be assayed as well. 6,77 Contrary to Dr Hamblin’s experience (May 10, p. 1090), we have found the simple haematological tests at least as useful as serum iron concentration and iron-binding capacity in the important differential diagnosis between iron" deficiency anaemia and the anaemia of chronic disorders " (in the latter the film is usually normochromic and normocytic,9 unless there is superimposed iron deficiency). They are also performed much more quickly and cheaply. son
on
Department of Chemical Pathology, Westminster Medical School, 17 Page Street, London SW1P 2AR.
PEPTIC ULCER
SIR It is a pity to discuss, as you did in your editorial of May 10 (p. 1074), two separate diseases, gastric and duodenal ulcer, under the conglomerate title, peptic ulcer. It is absurd to ignore the evidence for hereditary factors. These two diseases are inherited separately, the first-degree relatives of patients with duodenal ulcer having about three times the incidence of duodenal ulcer in a control population, and first-degree relatives of patients with gastric ulcer having about three times the incidence of gastric ulcer in a control population. 10, 11 Moreover, the Danish twin data suggest that genetic and environmental factors are about equal in importance in these diseases.12 Department of Surgery, Royal Postgraduate Medical School, London W12 0HS.
SIR,-I, too, have been campaigning for years against indiscriminate requests for serum iron and iron-binding capacity,5-7 and I should like to congratulate Mr Sanderson on his letter (April 26, p. 988). As he says, it is part of the much wider problem of uncritical investigation, which is always discouraged by pathologists for reasons some are explained half-jokingly by Dr Eastham in the last paragraph of his letter (May 10, p. 1090): the problem has also been discussed by us.8 I disagree with Mr Sandernot
of which
1. Beard, R. J., Brooke, B. N. Lancet, 1967, ii, 1113. 2. Zilva, J. F., Patston, V. M. ibid. 1966, i, 459. 3. Paterson, J. C. S., Marrack, D., Wiggins, H. S. J. clin. Path. 1953, 6, 105. 4. England, J. M., Fraser, P. M. Lancet, 1973, i, 449. 5. Zilva, J. F., Patston, V. J. ibid. 1966, i, 459. 6. Zilva, J. F. ibid. 1968, i, 636. 7. Zilva, J. F., Pannall, P. R. Clinical Chemistry in Diagnosis and Treatment; chapter xv. London, 1971. 8. Carter, P. M., Davison, A. J., Wickings, H. I., Zilva, J. F. Lancet, 1974, ii, 1555.
J. H. BARON.
OSTEITIS CONDENSANS ILII SIR,-The letter by Dr Richards and his colleagues (April 5, p. 812) raises some important issues on radionuclide imaging techniques as applied to bone. The 99m technetium-pyrophosphate method relies on the fact that pyrophosphate is incorporated into regions of bone associated with osteoblastic activity.13-15 In their letter, the McMaster investigators state: " The distribution of bloodflow in the sacro-iliac region was bilaterally symmetrical." The scintigraphic appearances immediately after injection of the radioactive material do reflect blood-pool, whereas a more proper reflection of bone reaction is obtained by of the appearances after a suitable (3-4 hours) delay.14,16 We have measured this delayed uptake of isomer in 7 patients with osteitis condensans ilii and have found it assessment
to
ADAM TURNBULL.
JOAN F. ZILVA.
be increased in 5. The appearances
-
conventionally recorded by scintiscanning require interpretation. It is important to remember that this interpretation is susceptible to the same subjective error as the interpretation of X-rays and that this difficulty is enhanced in patients with bilaterally symmetrical disease. The sacroiliac region is particularly difficultt to assess because of large bone mass and variation due to age. We have devised a technique which allows for precise measurement of the intensity of isomer uptake in the region of the sacroiliac joints in relation to the sacrum. 17 Using Gruchy, G. C. Clinical Hæmatology in Medical Practice; chapter VI. Oxford, 1970. 10. Doll, R., Buch, J. Ann. Eugen. 1950, 15, 135. 11. Doll, R., Kellock, T. D. ibid. 1951, 16, 231. 12. Jensen, K. G. Peptic Ulcer: Genetic and Epidemiological Aspects 9. de
based on Twin Studies. Copenhagen, 1972. 13. Bland, W. H. Nuclear Medicine; p. 454. New York, 1971. 14. Weber, D. A., Greenberg, E. J., Dimich, A., Kenny, P. J., Rothschild E. O. J. nucl. Med. 1969, 10, 9. 15. Kaye, M., Silverton, S., Rosenthall, L. ibid. 1975, 16, 40. 16. Genant, H. K., Bautovich, G. J., Singh, M., Lathrop, K. A., Harper, P. V. Radiology, 1974, 113, 373. 17. Russell, A. S., Lentle, B. C., Percy, J. S. J. Rheumatol. (in the
press).
