Again, in gout the deposition is sudden and associated with an acute paroxysm; while in nephritis it is gradual and unassociated with inflammatory reaction.
In gout the uratic deposits are overt, manifest as tophi; in nephritis, occult and unrevealed (ante-mortem).
Uratic deposits in the form of tophi occur in gout, in the absence of clinically recognisable interstitial nephritis. But tophi do not occur in nephritis if uncomplicated by gout.
In conclusion, the mere fact that uratic deposits affect such widely disparate forms in these two disorders is to our mind a sure indication that their mode of origin and formation is equally diverse—the one vital, biological; the other passive, mechanical.
Clinical Associations of Gout and Granular Kidney
It cannot be denied that gout and granular kidney are frequently met with in close association. But neither can it be disputed that in these disorders, as in many others, their outward affinities do but hark back to inward disparities. The occasional overlapping of the two affections, the trenching of the one upon the clinical or pathological territory of the other, must not blind us to the essential distinctness of the two morbid entities. Doubtless to the earlier advocates of the renal theory their not infrequent co-existence bespoke some hidden nexus, and at least seemed confirmatory of their views as to the pathogeny of gout. But, even if we allow that the connexion between the two disorders seems superficially intimate, it cannot be gainsaid that it is neither constant nor essential. For we have to recollect that—
(1) Some gouty subjects never develop granular kidney.
(2) Some individuals with granular kidney never develop gout.
Also we have to recall that—
(1) Paroxysms of gout often occur for many years before the symptoms of interstitial nephritis develop.