MO058: Do Renal Biopsies Assist Understanding of Loin Pain Hematuria Syndrome?
Bibliographic record
Abstract
Abstract BACKGROUND AND AIMS Loin pain-hematuria syndrome (LPHS) first described in 1967 is a complex and poorly understood rare disease, with a prevalence of 0.012%. It predominantly affects young women in their late 20s and early 30s2. Patients with LPHS experience extreme flank (loin) pain that can be unilateral or bilateral, along with gross or microscopic hematuria. In most cases, the pain is so severe that the patients are forced to quit their jobs, become opiate dependent, need antidepressants, require long term disability and a proportion contemplate committing suicide. Due to inadequate understanding of the pathophysiology of LPHS, the goal of management has been limited to symptomatic relief and pain management. As there are still gaps in our understanding of glomerular hematuria, we opted to assess the histopathological features of kidney biopsies of 14 LPHS patients to evaluate the correlation of glomerular basement membrane (GBM) alterations with hematuria and pain. METHOD In this cross-sectional study, 14 patients with LPHS underwent kidney biopsies. Demographic data (sex, age, ethnicity, weight and height), renal biomarkers (urine blood, urine protein and serum creatinine) and comorbidities were obtained prior to the procedure. The kidney biopsies were investigated under light microscopy, immunofluorescence microscopy and electron microscopy. Descriptive statistics were used to report baseline characteristics and histology findings. RESULTS All 14 patients were female, with median age 37 years. About 78.6% of the patients were Caucasian. None of the 14 patients had an abnormal glomerular filtration rate or an elevated albumin creatinine ratio (>3 mg/mmoL). 11/14 patients had macroscopic hematuria with 7/11 reporting gross hematuria with exacerbations of loin pain. 5/14 patients showed evidence of endothelial injury. Of the 14 patients, 1/14 had an insufficient sample, 1/13 had thick glomerular basement membrane, 1/13 had IgA nephropathy and 11/13 had normal GBM (Table 1). Regardless of GBM thickness, most patients had RBC cells ± casts implying glomerular leak. There was no evidence of podocyte injury. The presence of endothelial cell injury by electron microscopy may suggest a role for vascular damage in the pathogenesis of at least a subgroup of LPHS patients. CONCLUSION The array of histological changes identified in our study offers some understanding of the hematuria component but cannot explain pain as most patients did not have histological evidence of interstitial edema. In conclusion, our findings indicate that there is an urgent need for advanced understanding of molecular mechanisms underlying the heterogeneity of this disease. In our next phase of the study, we intend to compare gene signatures of LPHS patients with patients with isolated hematuria (without pain) to help enhance our understanding of unique genetic predisposing factors to this disease.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".