Gout, with a section on ocular disease in the gouty

by Llewellyn J. Llewellyn

(b) Inflammatory reaction is, we believe, an invariable precursor in all gouty processes.

In other words, we suggest that, although abnormalities of metabolism form an integral part of gout, they are of themselves inadequate to achieve its efflorescence. Thus, when we came to consider the elemental manifestations of gout, i.e., uratic deposits or tophi, we saw that neither the purely physical nor the purely chemical theory of their origin would suffice, nor, for that matter, could any solution of this complex problem be gleaned from even a blend of the twain. In short, such hypotheses are too mechanical. The intrusion of some other factor, “some vital something biological,” seems essential for the elucidation of uratosis, i.e., uratic deposition. For this, not uricæmia, is the specific characteristic phenomenon of gout. If we cannot explain uratosis on physical or chemical grounds, then how much less, in view of the non-toxicity of uric acid, can we, on this basis, account for the inflammatory phenomena of the disorder?

Inflammatory reaction is, we hold, an invariable antecedent in all gouty processes, whether of articular or ab-articular site. Granted that inflammatory reaction is a necessary prelude, the specificity of gout is attested by the fact that this same is followed by the deposition of urates. But while the sequential uratic deposition invests all forms of “gouty” inflammation with a specific character, unshared by any other disease, it follows that the cause of the said inflammation must, if possible, be ascertained.

For Walker Hall “the contention that gout lowers the general tissue resistance, and so opens the way to bacterial infections, is so obvious that it need hardly be formulated.” In light of this, we need have the less diffidence in hazarding our opinion that the morbific agent responsible for “gouty” inflammation is an infection or sub-infection. Now, in all forms of arthritis other than gouty, the intrusion of a germ is held to be self-explanatory and final; in short, all the local morbid changes and constitutional disturbances are held satisfactorily accounted for by the organism or its toxins.

The problem of gout, however, is not so simple. Its arthritis is peculiar in that it is always accompanied or followed by uratic deposition, which, be it noted, is not an ordinary sequel of inflammation. It is, in short, the outcome of inflammation supervening in an individual of gouty diathesis. What do we know of this latter?

The researches of the bio-chemists reveal that uric acid is the end-product of nuclein metabolism—the summation of a long chain of enzymatic reactions. Some indeed have thought to find an adequate explanation of gout in enzymatic abnormalities. Thus, Adami and McCrae suggest that gout is the outcome of insufficient oxidation, whereby the precursors of uric acid and similar bodies are not fully oxidised, and, by their accumulation and toxicity, set up morbid changes, and the uric acid formed is, in its turn, imperfectly oxidised and accumulates. This diminished oxidation is due to a constitutional deficiency of oxydases, inherited or acquired.

This opens up the old problem as to whether uric acid is an intermediary or a terminal product of metabolism. But, from evidence cited in preceding chapters, it appears probable, if not certain, that uric acid is an end-product. Moreover, as Gideon Wells observes, “the failure of recent studies on the enzymatic transformation of purins to locate anywhere in the human body an enzyme-destroying uric acid makes hazardous the attempt to explain gouty metabolism as a result of enzymatic abnormalities.”

Indeed, in view of this, as hitherto ascertained, absence of uricolytic enzymes, there can, as Wells says, “be little doubt that the fundamental reason for the existence of uric acid gout in man lies in the inability of the human organism to destroy uric acid. Consequently, inasmuch as man, unlike other mammals, cannot destroy uric acid rapidly by oxidation, he is always a potential victim of uric acid retention and deposition.”

Now we have, we hope, shown that there is no evidence that the uric acid retention in gout is due to functional inability on the part of the kidney to excrete uric acid. This being so, we have, as Von Noorden rightly says, no right to do violence to the facts by assuming that, in a case lacking any other evidence of nephritis, a condition of “latent nephritis” is the cause of the uric acid retention and deposition.

Similarly, there is at present no evidence forthcoming that the retention of uric acid is due to abnormal purin combinations in the blood. Nay, according to Wells, on the best evidence obtainable, uric acid exists in a free state in the blood, and not combined, as has been urged by many workers in this sphere.