VEGF-VEGFR2 inhibitor-associated hyaline occlusive glomerular microangiopathy: a Japanese single-center experience

Clinicopathological analysis of anti-VEGF drug-associated renal thrombotic microangiopathy: A case series and review of the literature

Anti-vascular endothelial growth factor-associated thrombotic microangiopathy (aVEGF-TMA) was recently discovered in patients with malignant tumors. Four aVEGF-TMA patients diagnosed by renal biopsy between 2018 and 2022 were identified, and all were females aged 30-62 years (mean age, 47 years). Two patients with malignant gastrointestinal stromal tumors who received sunitinib were analyzed. One patient was treated with bevacizumab plus regorafenib, which has never been reported before. Another patient had lung adenocarcinoma with multiple metastasis and was treated with bevacizumab. Proteinuria was often the first symptom, and the mean onset time was 23.25 months (7-36 months). Renal function was decreased in all patients, and nephrotic syndrome, hematuria, hypertension and anemia were present in some patients. Microscopically, both bevacizumab-TMAs and sunitinib-TMAs presented thrombi within dilated capillaries, mesangiolysis, double counters of the glomerular basement membrane and effaced or fused foot processes. Glomerulosclerosis and endothelial cell injury occurred in only some patients. Positive IgM deposits were observed in all aVEGF-TMAs, but IgA and C3 deposits were observed only in bevacizumab-TMAs. CD34 expression was absent around dilated capillaries containing thrombi, and immunostaining for fibrin/fibrinogen was positive; however, CD61 staining was negative in all patients. Thus, fibrin thrombi were suggested to be present in aVEGF-TMA. The mean follow-up time after renal biopsy was 19.5 months (range 14-32 months). One patient continued sunitinib treatment and eventually progressed to permanent dialysis, but tumor progression was controlled. The other three patients developed drug resistance, two patients discontinued aVEGF medication, and proteinuria decreased significantly. Notably, one patient recovered 14 months after withdrawal. The other patient who continued bevacizumab treatment had persistent proteinuria, and the tumor still progressed. In summary, renal function needs to be monitored in patients with malignant tumors who are receiving aVEGF drug treatment, especially females. Timely termination of related aVEGF administration after comprehensive assessment could alleviate their clinical symptoms. DATA AVAILABILITY: Data are available from the corresponding Author upon reasonable request.

SUrvey of renal Biopsy registry database and Anticancer dRUg therapy in Japan (SUBARU-J study)

Background

Kidney complications associated with anticancer drug therapy have greatly increased recently. We aimed to investigate the real-world clinical outcomes of anticancer drug therapy-associated renal complications in Japan using the national kidney biopsy database, Japan Renal Biopsy Registry (J-RBR).

Methods

From 2018 to 2021, 449 cases from 49 facilities identified as 'drug-induced' histopathology in the J-RBR were screened, of which a total of 135 were confirmed as anticancer drug-related cases and included in the analysis. Overall survival rates were estimated using the Kaplan-Meier method and compared by logrank test. The Cox regression model was used to evaluate the association between variables and deaths.

Results

The most common primary sites of malignancies were the lung (33.3%), followed by gastrointestinal (16.3%) and gynaecological (11.1%) cancers. Tubulointerstitial nephritis (TIN; 47.4%) and thrombotic microangiopathy (TMA; 35.6%) were the most frequent diagnoses. All immunoglobulin A nephropathy, minimal change disease and crescentic glomerulonephritis (CrGN) cases were immune checkpoint inhibitor related. All CrGN cases were anti-neutrophil cytoplasmic antibody negative. Antibiotics were most frequently used concomitantly with anticancer drugs in TMA cases among subgroups (TMA versus others: 62.5 versus 27.5%; P < .001). Among TMA cases, the serum lactate dehydrogenase level tended to be higher in cytotoxic agent-associated TMA (CTx-TMA) than in other TMAs, but was not significant between groups (415.5 versus 219.0 U/l; P = .06). Overall survival was worse in CTx-TMA than in other TMAs (P = .007). The Cox model demonstrated proton pump inhibitor (PPI) use (hazard ratio 2.49, P = .001) as a significant prognostic factor, as well as the presence of metastasis and serum albumin level.

Conclusions

Our registry analysis highlighted various presentations of biopsy-proven kidney complications associated with anticancer drug therapy. Clinicians should be aware of worse outcomes associated with CTx-TMA and the prognostic role of PPI use.

Impact of prior bevacizumab therapy on the incidence of ramucirumab-induced proteinuria in colorectal cancer: a multi-institutional cohort study

BACKGROUND

The association between prior bevacizumab (BEV) therapy and ramucirumab (RAM)-induced proteinuria is not known. We aimed to investigate this association in patients with metastatic colorectal cancer (mCRC).

METHODS

mCRC patients who received folinic acid, fluorouracil, and irinotecan (FOLFIRI) plus RAM were divided into with and without prior BEV treatment groups. The cumulative incidence of grade 2-3 proteinuria and rate of RAM discontinuation within 6 months (6M) after RAM initiation were compared between the two groups.

RESULTS

We evaluated 245 patients. In the Fine-Gray subdistribution hazard model including prior BEV, age, sex, comorbidities, eGFR, proteinuria ≥ 2 + at baseline, and later line of RAM, prior BEV treatment contributed to proteinuria onset (P < 0.01). A shorter interval between final BEV and initial RAM increased the proteinuria risk; the adjusted odds ratios (95% confidence intervals) for the intervals of < 28 days, 28-55 days, and > 55 days (referring to prior BEV absence) were 2.60 (1.23-5.51), 1.51 (1.01-2.27), and 1.04 (0.76-1.44), respectively. The rate of RAM discontinuation for ≤ 6M due to anti-VEGF toxicities was significantly higher in the prior BEV treatment group compared with that in the no prior BEV treatment group (18% vs. 6%, P = 0.02). Second-line RAM discontinuation for ≤ 6M without progression resulted in shorter overall survival of 132 patients with prior BEV treatment (P < 0.01).

CONCLUSION

Sequential FOLFIRI plus RAM after BEV failure, especially within 55 days, may exacerbate proteinuria. Its escalated anti-VEGF toxicity may negatively impact the overall survival.

Glomerular Microangiopathy with Cellular Crescent-like Formation and Endotheliopathy Due to Ramucirumab Treatment for Metastatic Sigmoid Colon Cancer

We encountered a 77-year-old Japanese man who presented with nephrotic-range proteinuria 20 days after receiving ramucirumab treatment for metastatic sigmoid colon cancer. A kidney biopsy showed two characteristic histological findings. The first finding was podocyte injury with cellular crescent-like formation, although focal segmental glomerulosclerosis (FSGS) (collapsing variant) according to the Columbia classification may have been a more appropriate name for this injury, as hypertrophy and hyperplasia of epithelial cells, presumably resulting from podocyte injury, were seen between Bowman's capsule and the glomerular basement membrane (GBM); these changes appeared to be due to the collapse of the GBM rather than to GBM destruction with fibrinoid necrosis. The second finding was endotheliopathy characterized by prominent mesangial interposition via enlargement of the mesangial matrix with mesangiolysis. Proteinuria and renal dysfunction subsided after discontinuation of ramucirumab. Bevacizumab has been reported to induce glomerular microangiopathy with endothelial damage and swelling six months after treatment, but in this case, ramucirumab may have induced focal segmental glomerulosclerosis (FSGS) collapsing variant and glomerular microangiopathy with endotheliopathy via mesangial damage within 1 month. We believe that the damage to the glomerular podocyte and endothelial cells via mesangial damage secondary to ramucirumab in our patient was a different type of glomerular microangiopathy than the endothelial cell damage with enlargement of the subendothelial space caused by bevacizumab.

Pro- and anti-fibrotic effects of vascular endothelial growth factor in chronic kidney diseases

Renal fibrosis is the inevitable common end-point of all progressive chronic kidney diseases. The underlying mechanisms of renal fibrosis are complex, and currently there is no effective therapy against renal fibrosis. Renal microvascular rarefaction contributes to the progression of renal fibrosis; however, an imbalance between proangiogenic and antiangiogenic factors leads to the loss of renal microvasculature. Vascular endothelial growth factor (VEGF) is the most important pro-angiogenic factor. Recent studies have unraveled the involvement of VEGF in the regulation of renal microvascular rarefaction and fibrosis via various mechanisms; however, it is not clear whether it has anti-fibrotic or pro-fibrotic effect. This paper reviews the available evidence pertaining to the function of VEGF in the fibrotic process and explores the associated underlying mechanisms. Our synthesis will help identify the future research priorities for developing specialized treatments for alleviating or preventing renal fibrosis. Abbreviation: VEGF: vascular endothelial growth factor; CKD: chronic kidney disease; ESKD: end-stage kidney disease; ER: endoplasmic reticulum; VEGFR: vascular endothelial growth factor receptor; AKI: acute kidney injury; EMT: epithelial-to-mesenchymal transition; HIF: hypoxia-inducible factor; α-SMA: α smooth muscle actin; UUO: unilateral ureteral obstruction; TGF-β: transforming growth factor-β; PMT: pericyte-myofibroblast transition; NO: nitric oxide; NOS: nitric oxide synthase; nNOS: neuronal nitric oxide synthase; iNOS: inducible nitric oxide synthase; eNOS: endothelial nitric oxide synthase; sGC: soluble guanylate cyclase; PKG: soluble guanylate cyclase dependent protein kinases; UP R: unfolded protein response