Spectrum of Indication Kidney Biopsies in Community Acquired Aki

ABSTRACT

Introduction: Community acquired acute kidney injury (CA-AKI) in low income settings is different from that in the high income settings. Infections, poisoning, toxic envenomations and pregnancy related AKI are common. Kidney biopsy is seldom performed in these patients unless atypical clinical course or features are present. We have established a prospective cohort of patients with CA-AKI at the Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh in India. We present the spectrum of kidney biopsies in patients who underwent kidney biopsy in this cohort. Method(s) The study is a single centre, prospective, observational cohort study of patients with CA-AKI at PGIMER. Patients aged >12 years and with a diagnosis of CA-AKI are eligible for enrolment. Patients with underlying CKD, urinary tract obstruction, COVID 19, malignancy or heart failure are excluded. Clinical and laboratory data are recorded at baseline. Follow up visits are scheduled at 1 and 4 months after hospital discharge. Kidney biopsies are done only in those patients who have atypical clinical course or features (e.g. persistent kidney dysfunction despite other clinical improvement, strong clinical suspicion of dominant glomerular involvement or interstitial nephritis etc.). We present the spectrum of histopathological diagnoses that were recorded in such patients till date. Result(s) Till now, 646 patients have been included in the cohort. The leading causes of CA-AKI are sepsis (52%), obstetric complications (14%), envenomation (8%), nephrotoxic drugs (6%) and poisons (3%) (figure 1). 18.4% patients had died after CA-AKI. At >=3 months after CA-AKI, 16.3% patients had not recovered completely with persistent eGFR <60 ml/min/1.73m2. 44 patients had undergone kidney biopsy in this cohort. Incomplete recovery, and clinical or diagnostic dilemmas were indications for doing kidney biopsy. The leading clinical diagnoses in this subgroup were sepsis (23%), nephrotoxic drugs (23%), envenomation (9%), obstetric causes (6.8%) and others (25%). Acute interstitial nephritis, acute tubular necrosis and acute cortical necrosis were most common histologic diagnoses (table 1). Combinations of various histologic features were not uncommon. Pigment casts were recorded in 13 patients. 4 patients had acute cortical necrosis, 2 being after post-partum AKI and one each due to acute gastroenteritis and unknown animal bite. Glomerular involvement were recorded in 8 patients (table 1). Thrombotic microangiopathy was present in 4 patients. In this subgroup of patients who underwent kidney biopsy, 3 (7%) had died and 8 (18%) had eGFR <60 ml/min/1.73m2 at >=3 months. Figure 1 Causes of CA-AKI in patients [Formula presented] Table 1 Histologic diagnoses in kidney biopsies in CA-AKI cohort. [Formula presented] Conclusion(s) Acute interstitial nephritis and acute tubular necrosis, alone or in combination with other findings, were the most common histologic diagnoses in indication kidney biopsies in CA-AKI. Adverse outcomes (mortality or progression to CKD) are common after CA-AKI. No conflict of interestCopyright © 2023