Clinical and Military Outcomes of Kidney Diseases Diagnosed in Active Duty Service Members.

INTRODUCTION: Renal biopsy is a valuable tool for determining diagnosis, management, and prognosis of intrinsic kidney diseases. Indications for biopsy depend on the clinical presentation. Within the military, renal biopsies also enable medical review boards to make military service fitness assessments after diagnosis of a kidney disease. There are no recent studies evaluating kidney disease diagnoses and clinical outcomes after renal biopsy at military treatment facilities. Additionally, no studies have examined overall healthcare and military career outcomes following renal biopsy. MATERIALS AND METHODS: We retrospectively reviewed all native renal biopsies performed on active duty beneficiaries at the Walter Reed National Military Medical Center from 2005 to 2020. We determined the prevalence of those who progressed to end-stage kidney disease (ESKD), kidney transplantation, doubling of serum creatinine, nephrotic-range proteinuria (NRP; proteinuria >3.5 g/day), medical evaluation board (MEB) outcomes, and death. The Armed Forces Health Longitudinal Technology Application and the Joint Legacy Viewer electronic medical record systems were used to access clinical and laboratory data at the time of biopsy and subsequent outcomes. Death data were collected using the Defense Suicide Prevention Office database. RESULTS: There were 169 patients in the cohort, with a mean follow-up of 7.3 years. Mean age was 32 years; 79% male; 48% white; and 37% black. Sixty-seven percentage of them were junior or senior enlisted. The most common indication for renal biopsy was concomitant hematuria and proteinuria (31%). The most common histologic diagnoses were immunoglobulin A (IgA) nephropathy (23%), followed by focal segmental glomerulosclerosis (FSGS; 17%) and lupus nephritis (12%). Eleven percentage of them progressed to ESKD, of whom 87% received a kidney transplant (10% overall). Thirty percentage of the patients progressed to NRP and 5% died. Forty-seven percentage of our patients underwent MEB after diagnosis, and of these, 84% were not retained for further military service. Although IgA nephropathy was the most commonly diagnosed condition, FSGS and lupus nephritis diagnoses were significantly more likely to result in MEB. CONCLUSIONS AND IMPLICATIONS: Immunoglobulin A nephropathy was the most frequent histologic diagnosis in active duty service members undergoing renal biopsy between 2005 and 2020. Despite being largely young and previously healthy, 11% progressed to ESKD and 5% died. A confirmed histologic diagnosis was associated with separation from the service and the end of military careers for 84% of the patients in the cohort who underwent MEB.

Detection of PLA2R Autoantibodies before the Diagnosis of Membranous Nephropathy.

BACKGROUND: Circulating serum autoantibodies against the M-type phospholipase A2 receptor (PLA2R-AB) are a key biomarker in the diagnosis and monitoring of primary membranous nephropathy (MN). However, little is known about the appearance and trajectory of PLA2R-AB before the clinical diagnosis of MN. METHODS: Using the Department of Defense Serum Repository, we analyzed PLA2R-AB in multiple, 1054 longitudinal serum samples collected before diagnosis of MN from 134 individuals with primary MN, 35 individuals with secondary MN, and 134 healthy volunteers. We evaluated the presence and timing of non-nephrotic range proteinuria (NNRP) and serum albumin measurements in relation to PLA2R-AB status. RESULTS: Analysis of PLA2R-AB in longitudinal serum samples revealed seropositivity in 44% (59 out of 134) of primary MN cases, 3% (one out of 35) of secondary MN cases, and in 0% of healthy controls. Among patients with MN, PLA2R-AB were detectable at a median of 274 days before renal biopsy diagnosis (interquartile range, 71-821 days). Approximately one third of the participants became seropositive within 3 months of MN diagnosis. Of the 21 individuals with documented prediagnostic NNRP, 43% (nine out of 21) were seropositive before NNRP was first documented and 28.5% (six out of 21) were seropositive at the same time as NNRP; 66% (39 out of 59) of those seropositive for PLA2R-AB had hypoalbuminemia present at the time antibody was initially detected. Twelve participants (20%) were seropositive before hypoalbuminemia became apparent, and eight participants (14%) were seropositive after hypoalbuminemia became apparent. CONCLUSIONS: Circulating PLA2R-AB are detectable months to years before documented NNRP and biopsy-proven diagnosis in patients with MN.

A Case Report of Acute Renal Failure as a Result of Light-Chain-Mediated Acute Tubular Interstitial Nephritis in a 30-Year-Old Combat Veteran.

We present a 30-year-old combat veteran with an unclear exposure history, with multiple deployments who was later diagnosed with acute renal failure as a result of light-chain deposition disease. Despite a drastic decline in kappa light chains following chemotherapy; his renal function worsened, and he progressed to end-stage renal disease, requiring hemodialysis. Light-chain-mediated acute tubular interstitial nephritis is an uncommon type of monoclonal gammopathy of renal significance presenting with acute renal failure without significant glomerular disease. Our case illustrates that light-chain-mediated acute tubular interstitial nephritis may present clinically like acute interstitial nephritis and that renal biopsy is critical for diagnosis. We also explore possible links between various environmental and occupational exposures that could have precipitated his disease process at such a young age.