LONDON SATURDAY 10 APRIL 1971 BRITISH Br Med J: first published as 10.1136/bmj.2.5753.61 on 10 April 1971. Downloaded from MEDICAL JOURNAL What is Chronic Pyelonephritis? The term "chronic pyelonephritis" has been used in various many years to produce scarred, shrunken, chronically in- senses, and it is difficult to define clearly a disease denoted by flamed, and inadequate kidneys, though R. H. Heptinstall2 it. Clinicians, radiologists, pathologists, and bacteriologists has tentatively outlined a possible evolutionary course on have applied different criteria to the diagnosis, and variations pathological grounds. If such a sequence does occur, it is within these specialties are sometimes as wide as those necessary to determine whether or not the continued presence between them. of infecting organisms in the kidneys or urine is required, or Simply on histological grounds many renal conditions can whether the inflammation and damage can proceed inde- be mistakenly regarded as the outcome of pyelonephritis.' 2 pendently of the presence of bacteria. This already proble- These include chronic glomerulonephritis, renal artery matic issue is further obscured by the possibility that stenosis, renal arteriosclerosis, renal infarction, the kidneys infections of the urinary tract may be prone to supervene in associated with drug sensitivities, analgesic abuse and gout, conditions which, in their own right, can cause hypertension irradiation nephritis, obstruction of the urinary tract, a wide and renal damage.4-6 range of hereditary nephritides, and the haemolytic-uraemic If chronic pyelonephritis does exist, other questions are syndrome. P. B. Beeson's3 suggested alternative, "chronic posed. How may the disease be recognized before the kidneys http://www.bmj.com/ renal disease of uncertain aetiology," seems to be a more become severely damaged? Can antibiotic treatment amelior- appropriate description for many cases at present labelled ate or prevent it? Does urinary reflux cause damage or is it "chronic pyelonephritis." merely incidental? Is surgical treatment of reflux ever indi- However, both children and adults, especially pregnant cated? Accurate answers probably do not exist at present, but women, frequently sustain infections of the urinary tract. M. McGregor' has made a notable attempt at some of them Among the commoner organisms responsible are Escherichia while reviewing the implications of childhood urinary in- coli, Enterobacter aerogenes, Streptococcus faecalis, staphy- fections. He considers that progressive renal destruction of lococci, Proteus, and Pseudomonas. Such infection may persist the type commonly labelled chronic pyelonephritis can on 2 October 2021 by guest. Protected copyright. in some patients, in others recur. In many of them reflux of progress irrespective of continuing bacterial infection. urine from the bladder to the ureters or renal pelvis may be Whether or not infection has had some part in initiating the detected radiologically. Other patients may sometimes first changes in a given kidney often cannot be stated with be seen with chronic renal failure or hypertension or both, certainty. and be found to have small scarred kidneys with histological Fatal urinary tract infections in childhood, on McGregor's evidence of chronic inflammation. thesis, are largely restricted to a group of boys with obstruc- In some patients with hypertension the renal disease is tive congenital malformations, and these deaths occur in the mainly or entirely unilateral, and removal of the diseased first two years. Infection in newborn babies has a better kidney occasionally corrects or relieves the hypertension. Some prognosis provided it is not part of a septicaemic illness. but by no means all patients with such chronically inflamed Vesico-ureteric reflux nearly always accompanies kidneys kidneys have a history suggesting previous infection of the severely damaged by pyelonephritis. Such reflux is appa- urinary tract, and this has led to the postulate that infection rently usually congenital, and may disappear with advancing can result in chronic inflammatory lesions of the kidney. age. The combination of reflux with infection is particu- This is the usual concept of "chronic pyelonephritis." larly harmful and the kidneys of children under 5 years are The central problem is to discern the natural history of especially vulnerable. During late childhood and early adult this disease, if indeed it exists. Certainly some cases progress life most people with recurrent urinary infection remain in within a few years from an infection of the urinary tract to good health apart from the recurrences, and hypertension or a terminal renal failure with hypertension, but these examples decline in renal function is only occasionally seen. But a few are usually of persistent overt infection, often in association die of renal failure with or without hypertension, having, it with a -congenital renal abnormality. It is much less clear if, is suggested from indirect evidence, suffered a possibly and if so how, infection may progress after a latent period of subclinical renal infection associated with reflux in very © BRITISH MEDICAL JOURNAL 1971. All reproduction rights reserved NO. 5753 PAGE 61 62 BRITISH MEDICAL JOURNAL 10 APRIL 1971 early childhood. These patients do not seem to owe their " Milne, M. D., in The Human Adrenal Cortex, ed. A. R. Currie, T. Syming- ton, and J. K. Grant, p. 493. Edinburgh, Livingstone, 1962. decline to persistent infection or to reinfection. Pyelonephritis Pickering, G. W., High ,Blood Pressure, 2nd [edn., London, Churchill, 1968. of pregnancy is not often the primary cause of much renal 6 Heptinstall, R. H., in Renal Disease, ed. D. A. K. Black, 2nd edn., p. 350. damage, though it can unmask and seriously worsen pre- Oxford, Blackwell, 1967. Br Med J: first published as 10.1136/bmj.2.5753.61 on 10 April 1971. Downloaded from 7 Pears, M. A., and Houghton, B. J., Lancet, 1959, 2, 1167. existing disease. 8 Little, P. J., and de Wardener, H. E., Lancer, 1962, 1, 1145. Deaths from chronic pyelonephritis in childhood are exceptional and under the age of 40 rare. After this they become more frequent, especially in women, there being, it is thought, a disproportionate number of deaths from chronic pyelonephritis in women between 50 and 70 years of age. Ups and Downs in the Health Most of these patients are unlikely to be suitable for surgical correction of hypertension or to be accepted in a renal dialysis Service or transplant programme. McGregor believes that the extent of serious renal disease in early adult life as a result of child- During the decade up to 1969 the numbers of medical staff hood urinary infection has been exaggerated, though a few in the Health Service fluctuated, going up in some sections striking tragedies occur. Nevertheless, longevity, especially in of it and down in others.1 The total number of hospital beds women, may be considerably reduced. actually fell by 4°%. What did rise indisputably was the The diagnosis of chronic pyelonephritis presents formidable amount spent on it. In Great Britain as a whole this figure difficulties. Beeson3 considers there are no direct symptoms, more than doubled, from £707m. to £1,573m., though and that physical findings likewise are normal except for what this means in terms of real money (if such a thing those caused by renal insufficiency. Microscopical study of still exists) is hard to say. Despite inflation the increase formed elements in the urine may disclose surprisingly does seem to be substantial even though the antiquated little. Proteinuria is variable and never large in amount; corners of the Health Service that still remain show it bacteriuria alone is not diagnostic, while patients with un- to have fallen below the nation's real needs. questionable chronic pyelonephritis may have negative urine The number of hospital beds in Britain fell from 548,676 cultures. The provocation of urinary leucocyte excretion by in 1959 to 528,917 in 1969. The bulk of the vanishing administering intravenous pyrogen7 or prednisolone8 has beds were in psychiatric hospitals, their closure being the proved helpful, but unfortunately is not specific for pyelone- consequence of the greater emphasis on treating these phritis, similar findings being obtained in some patients with patients at home and as outpatients. But in the non- glomerulonephritis. Radiology seems the most helpful aid to psychiatric hospitals there was also a diminution of the diagnosis, the essential features being asymmetry and irregu- number of beds amounting to some 2,000. Nor was it larity of the renal outlines, with bluntitg of one or more only beds that became fewer: hospitals did so too. One calices and diminished cortical thickness at the corresponding hundred and seventy of them disappeared, comprising a sites. reduction of about 6%. But within the general reduction From the morbid anatomist's point of view Heptinstall 6 in the number of hospitals, and in contrast to the loss of has emphasized the coarse irregular scarring of chronic psychiatric beds, the number of psychiatric hospitals http://www.bmj.com/ pyelonephritis, there often being unequal reduction in the actually rose from 374 to 404 (8%). A notable feature of size of the two kidneys, in contrast to the symmetrical con- this changeover was the closure of 20 psychiatric hospitals traction of chronic glomerulonephritis and most other forms each containing more than 2,000 beds. At the same time of shrunken kidney. The depressed,