Nephritis in Childhood

Although it is now well over 100 years since Richard Bright described that group of diseases to which his name is still attached, no final agreement has yet been reached on their proper definition and classification. It is true that chronic pyelonephritis and essential hypertension have been defined as conditions clearly distinct from true nephritis in respect of their aetiology and early course, but nephritis itself, despite a multitude of classifications of varying degrees of complexity, still awaits a final analysis. Various and often multiple adjectives have been added to the word 'nephritis' in succeeding attempts to subdivide the condition into separate groups or entities, but it is notable that, of the many classifications proposed, not one has proved universally acceptable to both clinicians and pathologists. The classification probably most widely used in this country at present is that of Ellis (1942) in which Bright's disease is subdivided into nephritis, essential hypertension and 'miscellaneous conditions' in which 'the renal disorder is incidental to some other disease'. Ellis regards nephritis itself as divisible into two clearly defined types differing in aetiology, clinical features, histology and prognosis. He defines type 1 nephritis as an illness of acute onset, usually at a short interval after an acute infection, with haematuria as the most prominent and constant symptom, and in many cases some degree of hypertension and oedema. The majority of cases ultimately recover completely. Type 2 nephritis he describes as a disease of insidious onset characterized by generalized oedema, gross albuminuria, a progressive course and a uniformly bad prognosis. His terms 'type 1' and 'type 2 nephritis', carrying with them the implication of two separate and distinct diseases, are now in very wide use in the British medical literature but, so far as I know, the only critical appraisals of Ellis's views have been those of Davson and Platt (1949) and Enticknap and Joiner (1953). Both papers report a few cases which do not fit easily into type 1 or type 2 of Ellis's classification. Davson and Platt, while reserving judgment on whether type 1 and type 2 are separate entities aetiologically, consider that 'as a practical classification of nephritis the Ellis classification is an advance', while Enticknap and Joiner conclude that 'this classification has little to recommend it from a descriptive point of view'. Some years ago, in the course of a clinical trial of an antihistamine drug in the treatment of nephritis, I had occasion to extract and study the records of 265 consecutive cases of nephritis admitted to the Royal Aberdeen Hospital for Sick Children. The considerable difficulty experienced in fitting all the cases into two separate and clearly defined types prompted further consideration of these cases in the light of the Ellis classification. This analysis has been, of necessity, purely clinical, for comparatively few patients died and the amount of necropsy material available was quite insufficient to form the basis of any criticism of the Ellis classification from this angle. The clinical details, including the results of a long-term follow-up, are sufficient, however, for a clinical study of the natural history of nephritis originating in childhood, and the results of this study are here presented with particular reference to the validity of the Ellis classification from the clinical standpoint.