918

was against a beta-globulin component of avian serum,the reaction being common to all three species .tested(pigeon, budgerigar, and hen). This "coeliac-associated"antibody was present in a third of coeliac-disease patientsbut in only 1 of 14 patients with bird fancier’s lung and3 of 299 controls. None of the patients with coeliac dis-ease had bird-fancier’s lung precipitins in their serum.Unlike the antigen of bird fancier’s lung, the cceliac-associated antigen was not found in bird droppings, butit was present in hen egg-yolk.

These differences probably reflect the different originsof the antigens and routes of sensitisation in the two dis-eases : bird fancier’s lung is believed to result from

repeated inhalation of antigen found in bird droppings,whereas the antigen responsible for the precipitins in theserum of patients with coeliac disease is probably dietaryin origin (hens’ eggs are the chief suspect). The evidencefrom Faux and her colleagues supports this view; as withother antibodies against dietary constituents in patientswith cceliac disease," the cceliac-associated antibodiescorrelated with the severity of the jejunal mucosallesion. Berrill et al. did not state the exact nature of the

precipitins in their patients with cceliac disease. Withoutmore information we cannot say whether they are con-sistent with the diagnosis of bird fancier’s lung. Addi-tional evidence that cceliac lung disease differs from truebird fancier’s lung was the fact that provocation inhala-tion tests with avian serum had no ill-effects on pulmon-ary function.

5

Whether the pulmonary disorder in coeliac disease isin any way directly due to extrinsic antigen, avian orotherwise, is therefore still far from clear. However, itmay be relevant that the incidences of both coeliac dis-easell and some types of fibrosing alveolitis12 are in-creased in individuals bearing the tissue antigen HLAB8. This antigen, when accompanied by another, DW3,seems to be associated with a predisposition to many im-munopathic disorders, such as Graves’, Addison’s, andSjogren’s diseases, chronic active hepatitis, and juvenile-onset diabetes. These disorders, many of which havebeen reported in patients with cceliac disease,13,14 arecharacterised by the production of antibodies to variousantigens. Thus, instead of one disease being the directconsequence of another, the concurrence of such dis-eases may be due to a basic common immunological dys-function.

THE DORSAL COLUMNS REVISITED.

THE termites of science are not sufficiently honoured.They undermine and demolish established orthodox

opinions, clearing the ground for reconstruction. Eightyears ago, Wall’ thus attacked the classic belief aboutthe dorsal columns (posterior funiculi) of the spinalcord. This held that they transmitted detailed informa-tion about the location, intensity, and shape of a

10. Kumar, P. J., Ferguson, A., Lancaster-Smith, M., Clark, M. L. Scand. J.Gastroent. 1976, 11, 5.

11. Stokes, P. L., Asquith, P., Holmes, G. K. T., Mackintosh, P., Cooke, W. T.Lancet, 1972, ii, 162.

12. Turton, C. W. G., Morris, L. M., Lawler, S. D., Turner Warwick, M. ibid.1978, i, 507.

13. Lancaster-Smith, M., Swarbrick, E. T., Perrin, J., Wright, J. T. Postgrad.med. J. 1974, 50, 45.

14. Scott, B. B., Losowsky, M. S. Lancet, 1975, ii, 956.1. Wall, P. D. Brain, 1970, 93, 505.

mechanical stimulus applied to the skin, and that with-out them little could be made out about a stimulus,except that it had happened.

Part of his case rested on animal experiments in

which, after complete transection of the dorsal columns,recognition of weight, texture, two-point discrimination,vibration, and joint position persisted, or at any ratereturned. In man, really detailed and reliable informa-tion is naturally very rare; "deliberate experimentationis here impossible, and the only data available are theresults of disease and injury, neither of which producethe selective and clear-cut ... lesions possible in animalexperimentation."2 To the meagre stock of precariousinformation more has now been added: two cases of stabinjury, severing both dorsal columns and more, and oneof removal of a localised haemangioma, destroying partof one dorsal column.3 In each case, examination at op-eration defined the extent of damage with exceptionalprecision. And in each case the subsequent sensory losswas different from the orthodox prediction. "The pa-tients retained some ability to detect single pressure sti-muli, to localise them, to feel movement and speed ofmovement at some points in the skin, and to announcethe angle and change of angle of joints;" vibration sensewas lost in one patient, but retained (though impaired)in the other with complete dorsal-column section.Mere iconoclasm is not an honoured trade; Dowsing,4

who smashed so many images and windows in Suffolkin 1643, achieved only notoriety. Wall, in contrast, hasbegun the construction of new views on dorsal-columnfunction. It is well to recognise how far a conventionalneurological examination deviates from the conditionsof normal life. Tendon jerks are tested, yet their onlywell-established function is to provide information forneurologists. Sensory test stimuli are generally appliedto the unmoving skin, yet much of normal stimulationarises through the subject’s own movements; the un-moved skin, like the unmoved eye, may be a poor obser-ver ; the test situation is as natural as lying in bed wait-ing for fleas to bite. Different, and more taxing, is thetask of identifying an unknown object by handling;identifying a number drawn upon the skin is a half-wayhouse, since it too involves moving stimuli, although inthe handling test the movements are of course the sub-ject’s own. Dorsal-column damage greatly hampers per-formance in these tests. One may conclude that dorsalcolumns are peculiary important in sensory tasks thatneed analysis of both time and place, as happens withmoving stimuli. This conclusion seems to be a corollaryof the earlier, wider-ranging speculation that the dorsalcolumns are part of a "go and get more information"system, without which an animal just sits and waits forfurther stimulation. 1

There is always work for iconoclasts and rebuilders.The Bell-Magendie law asserts that anterior spinal rootscontain only efferent fibres. It is now clear that, at anyrate in cats, this law is quite untrue; there are some 30%of fine fibres in some anterior roots which are afferent,5The task of tracing them and accounting for them hasonly just begun.

2. Gray’s Anatomy (edited by R. Warwick and P. L. Williams); p. 816. London,1973.

3. Wall, P. D., Noordenbos, W. Brain, 1977, 100, 641.4. Cited in Muir, F. The Frank Muir Book; p. 241. London, 1976.5. Coggeshall, R. E., Ito, H. J. Physiol. Lond. 1977, 267, 215.