A case of secondary focal segmental glomerulosclerosis associated with malignant hypertension

Effect of hypertension on the long-term prognosis of children with primary focal segmental glomerulosclerosis-a retrospective cohort study

BACKGROUND

Primary focal segmental glomerulosclerosis is a common clinicopathologic syndrome. More than 50% of the patients may have hypertension, which can further deteriorate the renal function of patients. However, the impact of hypertension on the development of end-stage renal disease in children with primary focal segmental glomerulosclerosis is still unclear. The end-stage renal disease greatly increases medical costs and mortality. Studying the related factors of end-stage renal disease is helpful to prevent and treat end-stage renal disease. This study aimed to explore the impact of hypertension on the long-term prognosis of children with primary focal segmental glomerulosclerosis.

METHODS

The data of 118 children with primary focal segmental glomerulosclerosis admitted to the Nursing Department of West China Second Hospital from January 2012 to January 2017 were retrospectively collected. The children were divided into a hypertension group (n=48) and a control group (n=70) according to whether they had hypertension. The children were followed up (by clinic visit and telephone interviews) for 5 years to compare the differences in the incidence of end-stage renal disease between the two groups.

RESULTS

Compared with the control group, the proportion of patients with severe renal tubulointerstitial damage in the hypertension group was significantly higher (18.75% vs. 5.71%, P=0.026). Moreover, the incidence of end-stage renal disease was markedly higher (33.33% vs. 5.71%, P<0.001). Both systolic and diastolic blood pressure had a certain value in predicting the development of end-stage renal disease in children with primary focal segmental glomerulosclerosis (P<0.001 and P=0.025, respectively), and the predictive value of systolic blood pressure was relatively higher. Multivariate logistic regression analysis showed that hypertension was risk factors for end-stage renal disease in children with primary focal segmental glomerulosclerosis (P=0.009, relative risk: 17.022, 95% CI: 2.045-141.723).

CONCLUSIONS

Hypertension was a risk factor for poor long-term prognosis in children with primary focal segmental glomerulosclerosis. For primary focal segmental glomerulosclerosis children with hypertension, blood pressure should be actively controlled to prevent the development of end-stage renal disease. Moreover, due to the high incidence of end-stage renal disease, we should monitor the end-stage renal disease during follow-up.

Histopathological and Clinical Findings of Biopsy-Proven Focal and Segmental Glomerulosclerosis: A Retrospective Study

Background

Focal segmental glomerulosclerosis (FSGS) is characterized by the presence of glomerular damage on histopathological examination. The major defining symptom of FSGS is proteinuria, which indicates damage to the glomerular filtration barrier. Additionally, FSGS is the most common cause of primary nephrotic syndrome. However, in Saudi Arabia, there is a paucity of research on this topic. Therefore, this study was designed to examine the clinical features, laboratory findings, and presence of comorbidities in patients with FSGS to determine their effects on clinical outcomes.

Methods

We retrospectively analyzed the histopathological and clinical data of patients diagnosed with FSGS via biopsy at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, during the period 1989-2020. Biopsy samples were labeled according to the Columbia classification as tip, perihilar, cellular, collapsing, or not otherwise specified (NOS).

Results

We included 39 children and 21 adults. Males accounted for 54.1% of the sample. Hypertension was the most common comorbidity. Regarding FSGS subtypes, 60.9% of the lesions in the adult patients were collapsing lesions, followed by NOS (26.1%). In pediatric patients, 36.8% of the lesions were NOS, followed by collapsing lesions (28.9%). We also observed a very low rate of remission. In both age groups, the most common clinical presentation was nephrotic syndrome.

Conclusion

We found a high prevalence of collapsing and NOS FSGS subtypes in both the adult and pediatric age groups. The most prevalent outcome was the persistence of nephrotic syndrome with low rates of remission.

Nephrotic syndrome with focal segmental glomerular lesions unclassified by Columbia classification; Pathology and clinical implication

Background

The Columbia classification is widely used for diagnosis of focal segmental glomerulosclerosis (FSGS). In practice, we occasionally encounter segmental glomerular lesions unclassified as Columbia classification. We analyzed the clinical implication of unclassified segmental lesions comparing with Columbia-classified FSGS.

Methods

A retrospective cohort study from 13 local hospitals in Japan. From 172 biopsy cases diagnosed with FSGS or minimal change disease (MCD)/FSGS spectrum with unclassified segmental lesions, adult patients with nephrotic syndrome who received immunosuppressive therapies were included. The cases are classified by pathology, i.e., typical FSGS lesions sufficiently classified into subgroups of Columbia classification: collapsing (COL), tip (TIP), cellular (CEL), perihilar (PH), and not otherwise specified (NOS), and unclassified by the Columbia classification into three subgroups: “endothelial damage,”; “simple attachment,”; and “minor cellular lesion,”. The response to immunosuppressive treatment and 30% decline of eGFR were compared.

Results

Among 48 eligible cases, all were Japanese, 34 were typical FSGS; 13 TIP, 15 CEL, 6 NOS, and no COL or PH cases. Fourteen were unclassified cases: endothelial damage (n = 6), simple attachment (n = 5), and minor cellular lesion (n = 3). The median age of overall patients was 60 years old and the median of eGFR and urinary protein creatinine ratio was 51.5 mL/min/1.73m² and 7.35, respectively. They received similar therapeutic regimen. Kaplan-Meier analysis revealed no significant difference in treatment response between typical FSGS and unclassified cases. Evaluating among the subgroups, endothelial damage, simple attachment and minor cellular lesion showed similar treatment response to TIP or CEL. No significant difference was also observed in the 30% decline of eGFR.

Conclusions

Japanese adult patients with nephrotic syndrome showing unclassified segmental lesions as Columbia classification may be equivalent clinical impact as Columbia classification of FSGS.

A Case of Rheumatoid Arthritis Presenting with Renal Thrombotic Microangiopathy Probably due to a Combination of Chronic Tacrolimus Arteriolopathy and Severe Hypertension

A 51-year-old woman with rheumatoid arthritis presented with mild hypertension 20 months after tacrolimus treatment and developing proteinuria 24 months after the treatment. Tacrolimus was discontinued 27 months after the treatment, followed by heavy proteinuria, accelerated hypertension, and deteriorating renal function without ocular fundus lesions as a clinical sign of malignant hypertension. Renal biopsy revealed malignant nephrosclerosis characterized by subacute and chronic thrombotic microangiopathy (TMA), involving small arteries, arterioles, and glomeruli. Focal segmental glomerulosclerosis, probably secondary to chronic TMA, was identified as a cause of heavy proteinuria. The zonal tubulointerstitial injury caused by subacute TMA may have mainly contributed to deteriorating renal function. The presence of nodular hyalinosis in arteriolar walls was indicative of tacrolimus-associated nephrotoxicity. Together with other antihypertensive drugs, administration of aliskiren stabilized renal function with reducing proteinuria. Owing to the preexisting proteinuria prior to severe hypertension and the complex renal histopathology, we postulated that chronic TMA, which was initially triggered by tacrolimus, was aggravated by severe hypertension, resulting in overt renal TMA.

Pathologic glomerular characteristics and glomerular basement membrane alterations in biopsy-proven thin basement membrane nephropathy

BACKGROUND

Thin basement membrane nephropathy (TBMN) is diagnosed by diffuse thinning of the glomerular basement membrane (GBM) without any clinical and pathologic findings of Alport syndrome and the other renal diseases. TBMN is characterized clinically by benign familial hematuria but rarely develops into end-stage renal disease.

METHODS

In 27 cases of biopsy-proven TBMN, we evaluated the pathologic characteristics of TBMN, and examined the correlation between these pathologic characterizations and renal dysfunction.

RESULTS

All patients had hematuria, and 21 patients (77.8%) had proteinuria. In six patients (28.6%) who were more than 50 years of age, the estimated glomerular filtration rate (eGFR) decreased from G3a to G4 in the chronic kidney disease stage. Pathologically, an irregular decrease in intensity of type IV collagen α5(IV) chain was seen in GBM, and irregular thinning with diffuse rough etched images was observed on the GBM surface with several sizes of holes by low-vacuum scanning electron microscopy. The glomerular morphology of TBMN was characterized by an increased number of small glomerular capillaries with an increased extracellular matrix (ECM). These characteristic morphologic alterations were evident from a young age in patients with TBMN, but were not correlated directly with the decrease of eGFR, the degree of hematuria, and proteinuria. The decrease of eGFR in patients with TBMN who were more than 50 years of age might be primarily mediated by arteriolosclerosis-associated glomerulosclerosis and interstitial fibrosis.

CONCLUSION

Characteristic pathological glomerular findings and GBM alterations occurred from a young age but were not associated directly with renal impairment in biopsy-proven TBMN.

Complex glomerular pathology of thrombotic microangiopathy and focal segmental glomerulosclerosis forms tumor-like mass in a renal transplant donor with severe renovascular hypertension

The pathogenesis of glomerular hypertension-mediated FSGS and its histological variations in humans remains unknown. A 47-year-old man developed nephrotic syndrome, renal dysfunction, and malignant hypertension 2 years after donating a kidney to his son. The donor's remnant kidney developed renal mass at an upper pole which was fed by an aberrant artery that branched from the root of the renal artery. Furthermore, the main non-aberrant renal artery demonstrated severe stenosis that caused renovascular hypertension, resulting in malignant hypertension. Upon radiological examinations, a tumorous mass was detected. Because of progressive renal dysfunction, nephrectomy was performed. The kidney revealed a diffuse distribution of complex FSGS lesions, i.e., a random combination of cellular/collapsing FSGS and glomerular thrombotic microangiopathy, confined to the renal mass, whereas such lesions were absent in the non-mass portion. This indicated that severe glomerular hypertension alone caused FSGS with TMA features. Heterogeneous FSGS lesions let us surmise that glomerular hypertension promoted simultaneous damages in endothelial cells and podocytes, which synergistically progressed to glomerulosclerosis. This unique case uncovers causal relationships between unusual glomerular hypertension and severe forms of FSGS that was possibly caused by the disruption of homeostasis sustained by podocytes and endothelial cells.