BRIGHT demonstrated the existence of a morbid species characterized by inflammation of the kidney, albuminuria and oedema. He deemed the different clinical forms which this disease presents different phases of the same morbid condition. Physicians, after him, struck by the difference which these forms assume, subdivided Bright’s disease into two distinct diseases: parenchymatous nephritis and interstitial nephritis.

BRIGHT demonstrated the existence of a morbid species characterized by inflammation of the kidney, albuminuria and oedema. He deemed the different clinical forms which this disease presents different phases of the same morbid condition. Physicians, after him, struck by the difference which these forms assume, subdivided Bright’s disease into two distinct diseases: parenchymatous nephritis and interstitial nephritis.

There is, then, a dualist school opposed to the unicist school of Bright. It is represented principally by Lancereau. Is there really a single malady, of different characteristics, according to the phases which it goes through, or do there really exist several affections of different nature, incorrectly joined together by the single name of “Bright’s disease?”.

This question is difficult to answer. On the one hand is a fact impossible to contest, namely, that when parenchymatous nephritis ends neither by recovery nor by death, either in the first weeks or the first months of the disease, but pursues a slow and chronic course, it is soon accompanied by the symptoms and the lesions of interstitial nephritis, so that as a consequence in such a case, the interstitial nephritis, with ultimate renal atrophy, is indeed, the last phase of the parenchymatous nephritis; and that in such a case the theory of Bright is absolutely true.

On the other hand, it cannot be denied that there are cases in which the disease begins in an insidious manner, progresses very slowly, with more or less complete periods of remission, and with periods of aggravation characterized by a symptomatic complexus which has no resemblance to that of parenchymatous nephritis, and in which the kidney, throughout all periods of the disease, shows the lesions of interstitial nephritis, and ends fatally in renal atrophy.

In such cases the nephritis is interstitial in the outset, and rightly distinguished from Bright’s disease proper. To this must be added that interstitial nephritis is always joined of gout, of syphilis and of lead-poisoning; that it is accompanied, in consequence, by the hepatic, pulmonary, encephalic, and, especially, cardiac lesions common to arterio-sclerosis.

Physicians who, like Lecorche and Talamon, defend the unicist doctrine of Bright’s disease, strive to show that in acute cases, designated by the name of parenchymatous nephritis, there is always an affection of the heart and of the vessels analogous to that which is always observed in interstitial nephritis. They affirm that every nephritis is always accompanied by considerable increase in arterial pressure, and consequently by dilatation and then by hypertrophy of the heart.

Traube has explained these cardiac and vascular phenomena by the obstacle which the arterial circulation meets in the kidney in consequence of inflammation there. This explanation is questionable, but, what is more important, dilatation of the heart is by no means always found in all cases of Bright’s disease. (Lecorche, page 419.).

Thus, Bamberger’s statistics show 807 cases of primary Bright’s disease to be accompanied only 344 times by hypertrophy of the heart.

The statistics of Galabin cover 101 cases and show only 34 cases of hypertrophy. Upon autopsies made at the Charity Hospital and Berlin, Vais remarked that in 20 cases of parenchymatous nephritis, hypertrophy existed in 14 cases.

Labadie-Lagrave, in the Dictionary of medicine and Surgery, says, word for word, “that, if a certain degree of dilatation of the ventricles, together with fatty degeneration of the myocardium, is the rule in chronic parenchymatous nephritis, hypertrophy of the left ventricle is wholly foreign to the symptomatology of this nephritis.” (Article on “The Kidney,” page 783.).

Experiments made upon animals are not sufficiently unanimous in results to show that hindrance to the circulation determines cardiac hypertrophy and elevation of arterial pressure.

Ludwig tied the renal arteries without causing either elevation of arterial pressure or hypertrophy of the heart. Grawitz and Israel, contracting the renal and removing one of the kidneys, produced hypertrophy of the left ventricle, but did not increase arterial pressure.

Lewinski alone produced hypertrophy of the left heart and an increase in the arterial tension by contracting the renal arteries in dogs. (Leorche, page 407.).

The conclusion from the total of these experiments, and also from clinical facts, is that hypertrophy of the left ventricle, instead of being closely united tote existence of the parenchymatous nephritis, is only an exceptional occurrence in the course of this disease. Lecorche and Talamon, and those who uphold the doctrine of absolute unity, plainly exaggerate when they speak of hypertrophy of the heart as a constant lesion in this disease.

Increase of arterial tension, which, according to Huchard, has always for its corollary chronic inflammation of the arteries and hypertrophy of the heart, is the constant lesion of interstitial nephritis, for the reason that this latter form of disease is joined to the existence of gout, or of lead-poisoning, which has for its lesion general arterio-sclerosis.

It is difficult to say whether interstitial nephritis, supervening as terminal phase of parenchymatous nephritis, is accompanied by general arterio-sclerosis or not. It is difficult to say, because we have not yet studied this question of pathological anatomy, nor distinguished sufficiently simple interstitial nephritis from the interstitial nephritis which follows parenchymatous nephritis, and which constitutes Bright’s disease in its last stage.

Upon the whole, then, we hold that there is such a thing as an interstitial nephritis which, from beginning to end, has always the characteristics of sclerosis; that this nephritis is accompanied always by intense thirst, by polyuria, by albumin in the urine, usually in small quantity and sometimes but intermittently present, by pale urine of low specific gravity, with notable diminution of urea. Let us add, as a characteristic of this form of nephritis, that it is not usually accompanied by oedema, except in the period of cachexia.

Interstitial nephritis is, in symptoms and in lesions, absolutely distinct from parenchymatous nephritis. It is also distinguished by an extremely chronic course, a very long duration, and a constant termination by uraemic accidents.

Interstitial nephritis is, plainly distinguished from parenchymatous disease by its relations with gout, plumbism, and the general arterio-sclerosis accompanying these two latter conditions.

We shall, therefore, take chapters for the consideration of our subject: one for Bright’s disease, a morbid species; the other for interstitial nephritis, a disorder depending on arterio-sclerosis.


Bright’s disease is characterized by anasarca, albuminuria, and inflammation of the kidney, first parenchymatous, but finally interstitial, if the disease lasts long enough.

Bright’s disease has two forms-one markedly acute in its beginning, the order of insidious origin and chronic course.

1. Acute Bright’s Disease.-This may begin when the patient is in full health, or, on the contrary, by way of complication, in the course or at the end of acute diseases: scarlet fever, diphtheria, typhoid fever, pneumonia, etc.

An intense febrile movement, vomiting and headache mark the beginning of the disease. The patient usually feels a dull pain in the region of the kidneys, while at the same time the urine is diminished to quantity, although micturition is frequent; the urine often contains blood, is always high-colored, of specific gravity lower than normal-falling to 1010 or even 1006, together with, at the same time, a great diminution of urea, which falls as low as 9 grammes to the litre; but the characteristic feature is the presence of albumin in quantity habitually considerable (4, 6, 8, 12, grammes or more): sometimes the urine, when heated, solidifies in the tube.

At the same time the dropsy shows itself. It begins almost always in the face, in the eyelids or in the subconjunctival tissue. There is then observed what full of tears, and there is shown the raising of the ocular conjunctiva by a layer of liquid. OEdema increases over the face, the natural lines disappear, and the face-immobile, pale and shining-appears like marble. Dropsy spreads over the rest of the body and anasarca becomes general. The disease, thus established, progress rapidly, and terminate in some days or some weeks by death or recovery.

Death takes place customarily either fro internal oedema (oedema of the lung, oedema of the glottis, pleuritic effusion, pericarditis, encephalic dropsy); often general anasarca, diarrhoea and progressive enfeeblement characterize the last days of the disease; at other times uraemic accidents, of which the most frequent are eclampsia and coma, come to put an end to the sufferings of the patient.

When the disease is to terminate by recovery, the first symptom is the increase of the urine, which rises rapidly to 1,2,3, and 4 litres. At the same time the febrile movement disappears and anasarca diminished in proportion to the increase of the urine.

The liquid undergoes considerable change in composition- diminution of albumin, increase in urea, with, at the same time, increase in specific gravity to 1018 and 1022, are what we principally observe.

When this acute of Bright’s disease terminates neither by death nor recovery, it passes into the chronic state. The febrile movement disappears and anasarca diminishes. The urine increases in quantity; the albumin is less abundant, but persists. At this time the disease presents the course and symptoms which we shall find again soon when describing Bright’s disease, chronic from the outset.

2. Bright’s Disease, Chronic fro the Outset.-This form, like the preceding, may follow an eruptive fever, typhoid fever, diphtheria or pneumonia, but in this case the beginning, instead of being febrile and tumultuous, is wholly unperceived and unrecognized; only by asking patients about their past may we succeed in connecting this chronic form of Bright’s disease to the previous existence of one of the diseases in which parenchymatous inflammation of the kidney is observed.

In other cases damp cold, long continued, is the only cause to which we may attribute the development of the disease. Lastly, there are cases in which it is impossible to find or to establish the aetiology of this form of Bright’s disease, chronic from the outset. Loss of strength, a particular kind of anaemia, with paleness of the face, puffiness of the lids, interpalpebral oedema, pale urine voided frequently, especially at night, but in volume below normal, anorexia, and pain in the head mark the beginning of this form.

If one examines the urine, one finds specific gravity diminished from 1006 to 1010; urea falls also sometimes to 9 grammes per litre, but the principal characteristic is the presence of albumen in notable quantity, reaching 4,6,8,10 grammes and more.

After several months the disease shows its character more and more. Oedema increases considerably, changing place, seizing often the face in the morning and the ankles in the evening. There is waxy pallor; loss of strength is marked, while difficulty of breathing is caused by the least movement.

The disease thus established may be prolonged for months, or even longer, but never more than three years.

The course is not regularly progressive; there are exacerbations followed by more or less complete remissions.

The exacerbations are caused usually by a chill, by overwork, by emotion, but especially by errors of diet. They are characterized by a decrease in the urine, which sometimes becomes bloody and contains always a greater quantity of albumin. Anasarca makes progress. There is sometimes vomiting, sometimes headache, and always a loss of strength, until the patient is obliged to keep to his bed.

Then amelioration takes place; it is marked by an increase in the quantity of the urine, a diminution in albumin and anasarca, return of strength and appetite. This remission which is never as complete as in interstitial nephritis, nevertheless allows the patient to resume his occupation, in port, and under the influence of intelligent treatment may be prolonged for a greater or less period of time.

From exacerbation to remission, and from remission to exacerbation, the disease, sometimes slowly, sometimes more rapidly, comes tote period of cachexia. This period is characterized by considerable dropsy. Anasarca distends the lower limbs, the skin of which becomes the seat of erythema, of fissures and sometimes of gangrenous plaques. Effusions form in the peritoneum and in the pleura. A certain degree of pulmonary oedema is usually evident. The urine becomes more more and more scanty, albumin is always present, but may diminish in quantity nevertheless, without improvement in the condition of the patient.

Anorexia, vomiting, and diarrhoea, still help to diminish the strength of the patient.

Seated usually upon a chair, because stay in bed is no longer possible, a prey to dyspnoea, resulting from dropsy of the pleura and lungs, pale and swollen, with limbs cracked and dripping incessantly with the liquid which distends them, the patient would die of exhaustion if uraemic accidents did not more usually terminate the disease. Failure of sight and headache, are the usual symptoms of this ending, which takes place either from eclampsia or from apoplexy, or from asphyxia, caused by pulmonary oedema.

In other cases, Bright’s disease assumes a form more chronic and slower. The renal lesion, from parenchymatous becomes interstitial, and the disease shows is every way the symptoms, course, and duration of the sclerotic form which we shall shortly describe.

Pathological Anatomy.-The acute nephritic lesion is essentially a glomerulitis, desquamative and with variable alteration in the tubular epithelium, infiltration of the interstitial tissue by round cells, catarrhal inflammation of the straight tubes, and inflammation of the arterioles.

The kidneys are considerably increased in size; they ar sometimes hard and tense, sometimes soft. Hyperplasia is found only in the cortical substance. Divested of their envelope the kidneys are found sometimes of uniform redness, or sometimes presenting a mottled aspect tinged with yellow. The pyramids show a more or less violet red tint.

Microscopical Examination.-More or less advanced inflammation of the glomeruli, which are not all in the same condition; some are congested, others anaemic, some normal. Albuminous and granular exudations from certain capsules take place. At other times the exudations are haemorrhagic. The tubuli are in general dilated somewhat. The epithelial cells are infiltrated with fat; sometimes pale cylinders, sometimes red globules, the result of haemorrhages, fill the loops of Henle and the straight canal. The connective stroma is not intact; it is oedematous, and shows round cells, more or less confluent, which indicate a certain degree of interstitial nephritis. Lastly, the small arterioles show cylindrical of fusiform thickening, which is the beginning of an obliteration of these arterioles.

This lesion is susceptible of complete recovery, at least if we may believe clinical experience. In other cases it ends with death. It may also end by passage into the chronic state. And in this case we have to study the evolution of a lesion which ends sooner or later in interstitial nephritis.

This conclusion is not that of authorities who allow the absolute separation of parenchymatous from interstitial nephritis, but is typical of acute nephritis, parenchymatous in character, having burst forth, either on occasion of typhoid fever, scarlet fever or some other infectious disease, or even in consequence of the effect of cold, and being terminated after several years by the symptoms and lesions of interstitial nephritis.

It is impossible to deny the morbid transformation of one of these lesions into the other.

The large red kidneys, more or less mottled with yellow and gray, soft or indurated, are transformed when the disease passes to the chronic state into the large white kidneys. Then, by a continuation of the evolution into small granular kidneys, retracted, white or red.

In the acute period the interstitial tissue is but little attacked. We find at most a few round cells interposed here and there in form of a trial between the tubules and at the openings of the arterioles. But the longer the disease the more are interstitial lesions noticed, leading by their evolution to atrophy and retraction of the kidney. Thus, facts show us that parenchymatous nephritis, when it passes to the chronic state, assumes all the characters of interstitial nephritis.


We have already said that interstitial nephritis depends upon arterio-sclerosis.

The beginning of interstitial nephritis often passes unperceived; it is characterized by polyuria and polydipsia, analogous to that of diabetes. There is perceived at the same time increase in arterial tension. It is to this increase of arterial tension that we should attribute the symptom of the “dead finger,” deemed by Dieulafoy a sign of nephritis without albuminuria.

In this first period, as a matter of fact, albuminuria shows itself often only in a transitory way, at long intervals, and in quantity estimated with difficulty. As we have already said the urine is very abundant; it is pale, of very low specific gravity, which varies from 1002 to 1012, containing a quantity of urea less than normal. he urine is slightly turbid, and may reach 2, 3 and 9 litres.

Patients are often tormented by continual headache. Anorexia, vomiting, or diarrhoea, dimness of vision, and amaurosis are observed in this form as in the preceding, but “in interstitial nephritis, amaurosis is related, not to a primitive alteration in the elements of the retina, but to a sclerotic alteration of the optic nerve and of the retina.” (Lancereau.).

OEdema may be completely lacking during nearly all the course of the disease. It is only when the nephritis has lasted for years, and when the patient becomes cachectic, that a certain degree of dropsy is evident, while at the same time albumin may reach 1,2, and 3 grammes per litre.

We must call attention to the cardiac symptoms which always accompany interstitial nephritis.

We have already referred to arterial tension. We must add to it hypertrophy of the heart and the “bruit de gallop,” which is often so diagnostic of this disease.

We must not forget, moreover, that interstitial nephritis is only an affection of arterio-sclerosis, and consequently that it may be accompanied by the cardiac, pulmonary, hepatic, and cerebral symptoms peculiar to this lesion of the arteries.

Interstitial nephritis progresses slowly, and is prolonged for years. It shows, from one time to another, periods of aggravation, characterized either by bloody and scanty urine or by the appearance of oedema, or, above all, by manifestations of uraemic symptoms, of which we shall speak in a moment. These aggravations are always due to errors of diet or to failure to observe the rules of health; subsequently, an amelioration, more or less complete, takes place, and thus the disease is prolonged through many years.

Almost always death comes from uraemic accidents, which may assume two principal forms, pulmonary and cerebral.

In the pulmonary form the patient is seized by paroxysmal dyspnoea, which comes especially at night, and which may be accompanied by pulmonary congestion, with expectoration of rust- colored sputum. This dyspnoea may lead to the death of the patient.

The cerebral form is much more frequent. A number of patients show symptoms of cerebral apoplexy, together with hemiplegia, and die comatose.

Others have veritable attacks of eclampsia, more or less intense and more or less lasting, taking, in severe cases, a subintrant course, such that the patient are in a veritable “etat de mal,” and die comatose.

Other patients resist uraemic eclampsia. Some gain their health completely, at least in appearance, and my yet live for a long time after having experienced its attack.

Uraemic accidents are always ushered in by a considerable diminutions in the quantity of urine, just as amelioration is accompanied by abundant diuresis. Dimness of vision, increase in headaches, slight twitching of the limbs often precede and usher in serious uraemic accidents.

Aetiology.-The causes of interstitial nephritis are first and foremost the causes of arterio-sclerosis. Abuse of strong liquors, life in a damp locality, and chilling of the body are circumstances which favor localization of arterio-sclerosis in the kidney.

Pathological Anatomy.-In interstitial nephritis the two kidneys are invaded almost equally. In the first stage the lesion is characterized by congestion and increase in the volume of the kidney; the capsule is easily detached form the organ; the parenchyma, slightly soft and pale, varies in color from red to gray, and is sown with capillary dilatation. On section, the cortical substance is brownish, with gray or white stains, the medullary substance of a violet hue. Histological examination shows a more or less abundant proliferation of embryonic elements spread unequally throughout the cortical substance, and seizing upon the connective and vascular tissue of the region of the convoluted canaliculi and of the corpuscles of Malpighi. Sometimes the Malpighian glomeruli are the seat of a haemorrhage which becomes mixed with the urine.

The kidney diminishes gradually in volume, its tissue is retracted, and its surface becomes roughened in all its extent. The kidney takes on a solid and coriaceous consistency; its capsule becomes adherent and is removed with difficulty. More or less numerous cysts are formed. Atrophy of the kidney takes place upon the cortical substance, which is sometimes reduced to a millimetre. The round cells, of which we have already spoken, stretch out and form fusiform bodies soon to be transformed into cicatricial tissue.

Next retraction supervenes, with atrophy of the convoluted tubes and of the glomeruli.

The epithelia of the tubes undergo a granulo-fatty degeneration, and end by disappearing.

The lesion, having arrived at its last stage, shows the kidneys reduced to the size of large chestnut, and in weight 190 grammes, [About six ounces Troy.] partly transformed into fibrous tissue, and then constituting that which is called the small red kidney.

The renal artery is, like most of the arteries of the body, attacked by arterio-sclerosis.

It is useless to describe here the lesions common to arterio-sclerosis and to gout, of which interstitial nephritis constitutes only an affection.

Differential Diagnosis Between the Two Nephritis.-This paragraph is perhaps superfluous. We wish, however, to call to mind that true bright’s disease is distinguished form interstitial nephritis by the intensity of the anasarca and by urine so well marked in character, namely, scanty and loaded with albumin; while in interstitial nephritis the urine is exceedingly abundant, with albumin scanty, or but a trace. Cardiac symptoms; hypertrophy of the heart, the “bruit de gallop;” Cardiac symptoms of aortitis; arterial tension, and more or less general arterio- sclerosis serve to distinguish interstitial nephritis and permit us to recognize it.

Clifford Mitchell