Interstitial nephritis natural history, complications and prognosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [[1]]; Associate Editor(s)-in-Chief:Mohsen Basiri M.D.

Overview

In the majority of patients with TIN, recovery of function has been observed, and improvement immediately occurs upon stopping the offensive agent.

Nevertheless, about 12% of patients may progress to develop ESRD and its complications; and thus require dialysis or transplantation.

Natural History, Complications, and Prognosis

Natural History

• The symptoms of (disease name) usually develop in the first/ second/ third decade of life, and start with symptoms such as ___.
• The symptoms of (disease name) typically develop ___ years after exposure to ___.
• If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].

Complications

• Common complications of TIN include:
  • Hypertension
  • Electrolyte and acid-base disorders
  • ESRD

Prognosis

In the majority of patients with TIN, a full recovery or partial recovery occurs upon stopping the offensive agent. Meanwhileabout 12% of patients may progress to develop ESRD and its complications; and thus require dialysis or transplantation.

it has been suggested previously that the long-term outcome is worse if renal failure lasts for >3 weeks [10,13];

Two series have shown worse prognosis with increasing age [10,28],

Attempts have also been made to gain prognostic information from the renal biopsy. Only the degree of tubular atrophy predicted renal outcome in our series.

Some authors have reported that patchy cellular infiltration predicts a better outcome than diffuse disease [13,28]. However, recent studies have not supported a correlation between the degree of cellular infiltration or tubulitis and outcome [15,29]. The degree of interstitial fibrosis has been correlated to outcome [29,30], but in other studies there is no such relationship [31]. These conflicting observations may be due to the patchy nature of the disease and the random sampling on renal biopsy. The infiltrate is generally most prominent at the corticomedullary boundary, and the medulla is relatively spared [32].

In chronic tubulointerstitial nephritis the most serious long term effect is kidney failure. When the proximal tubule is injured sodium, potassium, bicarbonate, uric acid, and phosphate intake may be reduced or changed, resulting in metabolic acidosis, hypokalemia, hypouricemia, hypophosphatemia). Damage to the distal renal tubule may cause loss of urine concentrating ability and polyuria.