Paratubular basement membrane insudative lesions predict renal prognosis in patients with type 2 diabetes and biopsy-proven diabetic nephropathy

A case of bullous pemphigoid and renal disease after dipeptidyl peptidase 4 inhibitor administration

A 62-year-old man with type 2 diabetes was admitted because of a decrease in estimated glomerular filtration rate from 72 to 17.5 mL/min/1.73 m2 in 10 years and development of widespread bullous skin lesions. His hemoglobin A1c level had been maintained at 6.0-7.0% for 10 years with a dipeptidyl peptidase (DPP)-4 inhibitor. Skin biopsy showed typical bullous pemphigoid, and kidney biopsy showed tubulointerstitial nephritis with eosinophilic infiltration and glomerular endothelial cell proliferation. After discontinuing the DPP-4 inhibitor, skin lesions improved, and renal decline slowed. This case indicates that DPP-4 inhibitors can cause not only skin lesions but also renal disease.

Dipeptidyl peptidase-4 inhibitor-related renal disease

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used to treat type 2 diabetes (T2D). Lowering blood glucose is expected also to reduce the progression of diabetic nephropathy. We experienced a patient with T2D who achieved good glycemic control with a DPP-4 inhibitor but experienced rapid deterioration of renal function. Therefore, we performed a retrospective study of similar patients treated at our hospital.

METHODS

Out of 56 patients with biopsy-proven diabetic nephropathy who underwent native kidney biopsy at Toranomon Hospital from January 2018 through December 2022, we selected 22 patients who had been receiving DPP-4 inhibitors for at least 9 months at the time of kidney biopsy. Of these patients, we evaluated 16 diagnosed with class IIa diabetic nephropathy according to Tervaert's pathologic classification. The yearly estimated glomerular filtration rate (eGFR) slope in the 16 patients was arranged from the highest to the lowest slope. Ten patients with a large eGFR slope had thrombotic microangiopathy (TMA)-like lesions characterized by glomerular endothelial cell proliferation and GBM duplication on kidney biopsy (group A), whereas the remaining 6 patients did not have TMA-like lesions (group B).

RESULTS

Group A had a median (interquartile range [IQR]) eGFR of 18.2 (16.2, 26.2) and a yearly median (IQR) eGFR slope of -11.2 (-17.6, -9.2) mL/min/1.73 m2 after of DPP-4 administration, whereas group B had a median (IQR) eGFR of 31.5 (21.9, 34.8) mL/min/1.73 m2 and a yearly median (IQR) eGFR slope of -1.6 (-3.1, -0.3). Renal function declined significantly more rapidly in group A than in group B, and proteinuria was higher in group A than in group B (median [IQR], 3.4 [2.6, 4.4] g/day vs 0.8 [0.4, 1.3] g/day, respectively). Five patients in group A progressed to dialysis during follow-up, but none of the patients in group B did. Median (IQR) hemoglobin A1c was 6.2 % (6.0 %, 6.6 %) in group A and 5.8 % (5.7 %, 6.6 %) in group B.

CONCLUSION

DPP-4 inhibitors promote vascular endothelial regeneration, but when this effect occurs in the glomerulus, glomerular endothelial cell proliferation leads to TMA-like lesions, which may cause an increase in proteinuria and rapid decline in renal function.

The role of Kimmelstiel-Wilson nodule in the kidney outcome in patients with diabetic kidney disease: A two-center retrospective cohort study

AIMS

In the current study, we aimed to investigate the predictive value of the Kimmelstiel-Wilson (K-W) nodule for the risk of ESKD in patients with type 2 diabetes mellitus (T2DM).

METHODS

In the two-center retrospective study, clinical and pathological parameters were compared between DKD patients with and without K-W nodules. Furthermore, we used Cox regression analysis to explore the predictive value of the K-W nodule for the risk of ESKD.

RESULTS

Compared with DKD patients without K-W nodules, patients with K-W nodules had a significantly higher level of proteinuria [5.1(3.1, 8.0) g/24 hr vs. 2.4(1.1, 4.4) g/24 hr, p < 0.001]. Patients with K-W nodules had significantly higher interstitial fibrosis and tubular atrophy (IFTA) and arteriosclerosis scores than those without (p = 0.001 and p = 0.006). Kaplan-Meier analysis showed that the probability of developing ESKD was significantly higher in patients with K-W nodules than in those without (log-rank test, p < 0.001). However, after adjusting closer variables, the K-W nodule was not an independent predictor for the risk of ESKD (p > 0.05).

CONCLUSIONS

In T2DM patients with DKD, the K-W nodule was associated with a more severe phenotype, and to some extent, associated with poorer renal outcome, but might not be an independent risk factor for the progression of ESKD.

Addition of glomerular lesion severity improves the value of anemia status for the prediction of renal outcomes in Chinese patients with type 2 diabetes

We aimed to determine the utility of biopsy data and anemia for the prediction of renal outcomes in Chinese patients with type 2 diabetes. In total, 441 Chinese patients with type 2 diabetes and biopsy-confirmed diabetic nephropathy (DN) were enrolled in a retrospective study. Their renal pathology was assessed using the Renal Pathology Society system. Cox proportional hazards models were used to estimate hazard ratios (HRs) for end-stage renal disease (ESRD), and immunofluorescence staining was used to assess the expression of hypoxia-inducible factor (HIF)-α in patients’ kidneys. We found that glomerular pathology classification was an independent pathological predictor of low hemoglobin concentration, according to linear and logistic regression analyses. Each 1 g/dL decrease in baseline hemoglobin concentration was associated with a 42% higher risk of an adverse renal outcome, after adjustment for clinical and pathologic covariates. In patients with severe glomerular lesions, the risk of progression to ESRD was significantly higher if mild or moderate/severe anemia was present, but in patients with mild glomerular lesions, the risk was only significantly higher in those with moderate or severe anemia than in the absence of anemia. Harrell’s C Concordance was improved, but the Akaike information criterion was worsened by adding the glomerular pathology classification to the use of anemia status and clinical data. Immunofluorescence staining revealed that renal HIF-1α and HIF-2α expression was significantly higher in classes II–IV than class I. Thus, the addition of glomerular pathology classification increases the value of anemia status for the prediction of the progression to ESRD.

Association Between Diabetes and Major Bleeding Complications of Renal Biopsy

Introduction

Nephrologists have recently recognized the heterogeneity of kidney diseases among patients with diabetes and begun to actively perform percutaneous renal biopsies (PRBs). Nevertheless, the association between diabetes and major bleeding complications of PRB remains unclear.

Methods

In this retrospective cohort study using the Diagnosis Procedure Combination database in Japan, we identified patients who underwent an elective PRB from July 2010 to March 2018. The primary outcome was the occurrence of major bleeding complications, defined as red blood cell transfusion within 7 days after PRB or invasive hemostasis after PRB. Multivariable regression analysis was performed to analyze the association between diabetes and major bleeding complications with adjustment for patient and hospital characteristics.

Results

We identified 76,302 patients, including 8245 with diabetes. The proportion of PRBs performed for patients with diabetes continuously increased over time. Major bleeding complications occurred in 678 patients (0.9%), including 622 (0.8%) with red blood cell (RBC) transfusion and 109 (0.1%) with invasive hemostasis. Diabetes was significantly associated with major bleeding complications (relative risk [RR] = 2.41; 95% CI 2.00–2.90). Among patients with diabetes, multiagent or insulin treatment had significant association with major bleeding complications (RR = 1.57; 95% CI 1.18–2.10), compared with single-agent diabetes treatment.

Conclusion

Diabetes is significantly associated with major bleeding complications of PRBs. Moreover, severity of diabetes has association with increases in major bleeding complications. Thus, nephrologists should carefully judge whether the anticipated benefits outweigh the relatively high risk of major bleeding complications when considering PRB for patients with diabetes.

Prognostic models of diabetic microvascular complications: a systematic review and meta-analysis

BACKGROUND

Many prognostic models of diabetic microvascular complications have been developed, but their performances still varies. Therefore, we conducted a systematic review and meta-analysis to summarise the performances of the existing models.

METHODS

Prognostic models of diabetic microvascular complications were retrieved from PubMed and Scopus up to 31 December 2020. Studies were selected, if they developed or internally/externally validated models of any microvascular complication in type 2 diabetes (T2D).

RESULTS

In total, 71 studies were eligible, of which 32, 30 and 18 studies initially developed prognostic model for diabetic retinopathy (DR), chronic kidney disease (CKD) and end stage renal disease (ESRD) with the number of derived equations of 84, 96 and 51, respectively. Most models were derived-phases, some were internal and external validations. Common predictors were age, sex, HbA1c, diabetic duration, SBP and BMI. Traditional statistical models (i.e. Cox and logit regression) were mostly applied, otherwise machine learning. In cohorts, the discriminative performance in derived-logit was pooled with C statistics of 0.82 (0.73‑0.92) for DR and 0.78 (0.74‑0.83) for CKD. Pooled Cox regression yielded 0.75 (0.74‑0.77), 0.78 (0.74‑0.82) and 0.87 (0.84‑0.89) for DR, CKD and ESRD, respectively. External validation performances were sufficiently pooled with 0.81 (0.78‑0.83), 0.75 (0.67‑0.84) and 0.87 (0.85‑0.88) for DR, CKD and ESRD, respectively.

CONCLUSIONS

Several prognostic models were developed, but less were externally validated. A few studies derived the models by using appropriate methods and were satisfactory reported. More external validations and impact analyses are required before applying these models in clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018105287.

Associations Between High-Altitude Residence and End-Stage Kidney Disease in Chinese Patients with Type 2 Diabetes

Zhao, Lijun, Xi Wang, Tingli Wang, Wenxin Fan, Honghong Ren, Rui Zhang, Yutong Zou, Huan Xu, Jie Zhang, Yunhong Wu, and Fang Liu. Associations between high-altitude residence and end-stage kidney disease in Chinese patients with type 2 diabetes. High Alt Med Biol. 21:396-405, 2020. Background: This study investigated whether living at high altitude was associated with progression to end-stage kidney disease (ESKD) in Chinese patients with diabetic nephropathy (DN). Materials and Methods: This retrospective study included 369 patients with type 2 diabetes mellitus (T2DM) and biopsy-confirmed DN. Cox proportional hazards models were used to estimate hazard ratios (HRs) for the influence of living at high altitude on ESKD. Results: Patients living at ≥2,000 m above sea level were more likely to be Tibetan, and they had higher mean body mass indexes, glycosylated hemoglobin, hemoglobin concentrations, and baseline estimated glomerular filtration rates than those living at lower altitudes. During a median follow-up period of 20 months, 141 (38%) patients progressed to ESKD. In multivariable Cox analysis adjusted for age, sex, ethnicity, and clinical and pathological parameters, living at high altitude was independently associated with progression to ESKD in Chinese DN patients [HR 2.83, 95% confidence interval (CI) 1.05-7.58]. Compared with Han Chinese, Tibetans were at a lower risk of progression to ESKD (HR 0.15, 95% CI 0.04-0.59). Conclusions: Living at high altitude was independently associated with renal outcome in Han Chinese patients with T2DM and DN, but not native Tibetans.

Spontaneous membranoproliferative glomerulonephritis in a young Crl:CD-1(ICR) mouse

Here, we reported a spontaneous case of membranoproliferative glomerulonephritis observed in a young ICR mouse. A 5-week-old female mouse was euthanized owing to abdominal swelling and increased body weight. At necropsy, generalized subcutaneous edema, and clear, colorless, non-viscous ascites were observed. Histologically, the kidneys showed diffuse, bilateral glomerular lesions. The lesions were characterized by thickening and double contour of the basement membrane and an increase in mesangial cells and matrix, resulting in the narrowing of the capillary lumen. Additionally, eosinophilic hyaloid material accumulated in the subendothelial areas and Bowman’s space. The material was positive for periodic acid-Schiff, complement component C3, or immunoglobulin G, stained red by Masson’s trichrome, and stained blue by phosphotungstic acid-hematoxylin stain and was considered to be plasma due to glomerular leakage. The glomerular lesion was diagnosed as membranoproliferative glomerulonephritis, and an uncertain endothelial injury was suspected as the cause.

Histological Evidence of Diabetic Kidney Disease Precede Clinical Diagnosis

BACKGROUND

In the absence of a histological diagnosis, persistent albuminuria is globally accepted as the main diagnostic criteria for diabetic kidney disease (DKD).

METHODS

In the present retrospective study, we evaluated data from an Italian cohort of 42 deceased diabetic donors (mainly with type 2 diabetes). Using the kidney biopsies obtained at the time of donation to evaluate single or double allocation based on Karpinski score, we determined the prevalence of histological lesions attributable to diabetes.

RESULTS

All 42 donors presented with proteinuria in the normal range and an estimated glomerular filtration rate (eGFR) (chronic kidney disease [CKD]-EPI) >60 mL/min/1.73 m2. A kidney biopsy was available for 36 patients; of these, one was not interpretable and 32 showed histopathological lesions consistent with DKD and encompassing all histological classes. Thus, we found a relatively high proportion of histologically proven DKD that had been clinically undiagnosed, as none of the patient had significant proteinuria and eGFR <60 mL/min/1.73 m2.

CONCLUSIONS

The data we present here support the need to implement routine kidney biopsies in normoalbuminuric diabetic subjects in the early stages of CKD. Such strategy may help to improve risk stratification in diabetic patients and guide therapeutic decisions during the early stages of the disease.