COULD PROTEINURIA PREDICT THE RENAL PROGNOSES OF PATIENTS WITH TYPE 2 DIABETES MELLITUS AND DIABETIC NEPHROPATHY?

AIMS

This study investigated the relationship between proteinuria levels, clinicopathological features, and renal prognoses in Chinese patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN).

METHODS

Three hundred patients with T2DM and biopsy-proven DN were enrolled. Patients were stratified by 24-h proteinuria levels: Group 1:≤1g/24h); Group 2:1-3g/24h; and Group 3:≥3g/24h. Renal outcomes were defined as having reached end-stage renal disease (ESRD). The proteinuria level's influence on the renal outcomes was evaluated using Cox regression analysis.

RESULTS

Among subgroups stratified by proteinuria levels, systolic blood pressure, serum creatinine, BUN, cholesterol, DR and hypertension incidence, the incidences of patients who progressed to ESRD were the lowest in group 1 (P<0.05). However, eGFR, serum albumin and hemoglobin were highest in group 1. Patients with higher proteinuria levels had much lower five-year renal survival rates. Univariate analyses revealed that higher proteinuria levels were significant clinical predictors of renal prognosis (P<0.05), although they were not independent risk factors for progression to ESRD in the multivariate Cox proportional hazard analysis (P>0.05).

CONCLUSIONS

The higher the level of proteinuria, the lower the 5-year renal survival rate of DN patients, but there was no significant correlation between proteinuria level and 5-year renal survival rate. Other factors in the proteinuria group may have more significant effects on the 5-year renal survival rate, such as lower baseline eGFR, serum albumin, hemoglobin and higher cholesterol, higher incidences of DR and more severe lesions.

Processing of Mutant β-Amyloid Precursor Protein and the Clinicopathological Features of Familial Alzheimer's Disease

Alzheimer's disease (AD) is a complex, multifactorial disease involving many pathological mechanisms. Nonetheless, single pathogenic mutations in amyloid precursor protein (APP) or presenilin 1 or 2 can cause AD with almost all of the clinical and neuropathological features, and therefore, we believe an important mechanism of pathogenesis in AD could be revealed from examining pathogenic APP missense mutations. A comprehensive review of the literature, including clinical, neuropathological, cellular and animal model data, was conducted through PubMed and the databases of Alzforum mutations, HGMD, UniProt, and AD&FTDMDB. Pearson correlation analysis combining the clinical and neuropathological data and aspects of mutant APP processing in cellular models was performed. We find that an increase in Aβ42 has a significant positive correlation with the appearance of neurofibrillary tangles (NFTs) and tends to cause an earlier age of AD onset, while an increase in Aβ40 significantly increases the age at death. The increase in the α-carboxyl terminal fragment (CTF) has a significantly negative correlation with the age of AD onset, and β-CTF has a similar effect without statistical significance. Animal models show that intracellular Aβ is critical for memory defects. Based on these results and the fact that amyloid plaque burden correlates much less well with cognitive impairment than do NFT counts, we propose a "snowball hypothesis": the accumulation of intraneuronal NFTs caused by extracellular Aβ42 and the increase in intraneuronal APP proteolytic products (CTFs and Aβs) could cause cellular organelle stress that leads to neurodegeneration in AD, which then resembles the formation of abnormal protein "snowballs" both inside and outside of neurons.