3β-Hydroxysteroid Dehydrogenase Type 2 (3βHSD2) Deficiency due to a Novel Compound Heterozygosity of a Missense Mutation (p.Thr259Met) and Frameshift Deletion (p.Lys273ArgFs*7) in an Undervirilized Infant Male with Salt Wasting

Deficiency of 3β-hydroxysteroid dehydrogenase type 2 (3βHSD2) is a rare type of congenital adrenal hyperplasia (CAH), causing impaired steroid hormone production in both adrenals and gonads. Phenotype ranges, according to the genetic defect, from the salt-wasting form in both sexes to undervirilization in males and virilization in females. We present a 13-month-old male infant who was admitted to the hospital with signs of adrenocortical insufficiency and genital ambiguity. Clinical presentation, hormonal profile, laboratory evaluation, and karyotype were suggestive of the salt-wasting form of CAH due to 3βHSD2 deficiency. Mutational analysis revealed a missense mutation c.776C>T (p.Thr259Met), inherited by the mother, and a frameshift deletion c.818-819delAA (p.Lys273ArgFs*7), inherited by the father. Both mutations are considered pathogenic. To our knowledge this is the first case of an undervirilized male infant with salt wasting bearing this pathogenic frameshift deletion p.Lys273ArgFs*7 in compound heterozygosity with the missense mutation p.Thr259Met.

Distinctive features of pancreatic neuroendocrine neoplasms exhibiting an increment in proliferative activity during the course of the disease

PURPOSE

Neuroendocrine neoplasms (NENs) differ in their biological behavior and growth potential in a way that can be predicted using histological classification and grading systems. A subset of pancreatic NENs (pNENs) may develop a more aggressive phenotype during the course of the disease, associated with an increase in the Ki-67 proliferation index (PI). The purpose of the study was to present the clinical characteristics of these patients.

METHODS

Using re-biopsy of growing lesions, we investigated the increase in Ki-67 PI sufficient to change initial grading (G).

RESULTS

Of 264 patients with well differentiated (WD) pNENs who showed progressive disease during follow-up, 15 (6%) exhibited an increase in Ki-67 PI at a median time 36.8 (9.3-255.8) months. All neoplasms had WD-morphology: five had G1 (Ki-67 median value 1%), nine G2 (median value 5%), one G3 (25%) grades. Upon change of Ki-67 PI, 3 patients had G2 (8%) and 12 G3 (57.5%) NENs, while all retained their WD-morphology. At last follow-up, eight patients were alive with a median overall survival (OS) of 52.5 (9.5-264.3) months. Μedian OS was shorter in patients who had a change in Ki-67 PI before 36 months compared to those who had a change of Ki-67 PI at a later stage (27.5 95%CI: 11.88-43.06 vs. 120.87 95%CI: 96.05-145.69; log-rank p = 0.018).

CONCLUSIONS

During the course of their disease, 6% patients with progressive pNENs develop an increase in Ki-67 PI resulting in an increase in grading status while maintaining their morphology. This process is associated with worse OS when it occurs at an early stage.

Role of Receptor Profiling for Personalized Therapy in a Patient with a Growth Hormone-Secreting Macroadenoma Resistant to First-Generation Somatostatin Analogues

Background: Acromegaly is almost always caused by a pituitary adenoma and is associated with high morbidity and mortality when uncontrolled. Trans-sphenoidal removal of the adenoma is the mainstay of therapy, but fails to control the disease in a significant number of patients who require further treatment. Somatostatin analogues (SSAs) as monotherapy or in combination with growth hormone (GH)-receptor antagonists and/or dopamine agonists are used either alone or in combination following surgical failure to achieve disease control. The use of specific biomarkers may help to individualize the therapeutic plan after surgical failure and direct towards a more personalized approach. Methods: We report a 41-year-old man with acromegaly and residual disease after repeated surgery that was resistant to first-generation SSAs. Results: Biochemical and tumor control were achieved following the administration of a second-generation SSA, pasireotide, combined with pegvisomant, both at maximal doses and along with cabergoline. Histology specimens showed a sparsely-granulated GH-immunostaining pituitary adenoma with intense positivity for somatostatin receptors 2 and 5 and low levels of E-cadherin. Conclusion: Personalized medical therapy guided by currently available biomarkers, such as immunohistochemically-characterized receptor profiling or adhesion molecules, resulted in controlled insulin-like growth factor-1 (IGF-1) and GH levels and symptom alleviation following the combination of three drug-classes.

Histopathological, immunohistochemical, genetic and molecular markers of neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) arise from cells of the neuroendocrine system located in many sites amongst which most common are the gastrointestinal (GI) system and the lung. The efforts to assess the specific site of origin or predict the biological behavior of NENs is based upon a detailed study of neoplasm's architectural pattern, immunohistochemical, genetic and molecular profile. Immunohistochemistry is used to characterize the aggressivity of NENs, by assessing the proliferation index Ki-67, as well as the neuroendocrine differentiation by assessing chromogranin A (CgA) and CD56. Basal panels of immunohistochemical markers such as CDX-2, Isl-1, TTF-1, PAX6/8 are currently being used to allocate the neoplasms, while in dubious cases new markers are investigating. Unraveling the genetic and molecular mechanisms of NENs pathogenesis along with shedding light on the molecular heterogeneity of neoplasms and the individual patterns of molecular lesions, underlining these neoplasms may provide new tools in terms of diagnostics and therapeutics. Molecular targeted therapies (MTTs) such as everolimus and sunitinib have been the first example of druggable molecular targets implicated in NENs that have been approved for NEN treatment. New investigational drugs are developing along with genetic tests that may allow the identification of the specific subset of patients that will respond to each individual MTT. Multiparametrical molecular and genetic analysis such as the NETest and the MASTER are already in trials shedding light in a step-by-step management of NENs that allow not only the selection of an appropriate therapeutic option but also the identification of response to treatment or early relapse allowing an early amendment of the strategy. Summarizing the combination of histopathological, immunohistochemical, genetic and molecular profile of a NEN opens new horizons in the efficient management of NENs.

Hsf-1 affects podocyte markers NPHS1, NPHS2 and WT1 in a transgenic mouse model of TTRVal30Met-related amyloidosis

INTRODUCTION

Familial amyloid polyneuropathy is characterized by transthyretin (TTR) deposition in various tissues, including the kidneys. While deposition induces organ dysfunction, renal involvement in TTR-related amyloidosis could manifest from proteinuria to end-stage kidney failure. As proteinuria is considered result of glomerular filtration barrier injury we investigated whether TTR deposition affects either glomerular basement membrane (GBM) or podocytes.

MATERIALS AND METHODS

Immunohistochemistry, immunoblot and gene expression studies for nephrin, podocin and WT1 were run on renal tissue from human-TTRV30M transgenic mice hemizygous or homozygous for heat shock factor one (Hsf-1). Transmission electron microscopy was used for evaluation of podocyte foot process width (PFW) and GBM thickness in Hsf-1 hemizygous mice with or without TTRV30M or amyloid deposition.

RESULTS

Glomeruli of hsf-1 hemizygous transgenic mice showed lower nephrin and podocin protein levels but an increased podocyte number when compared to Hsf-1 homozygous transgenic mice. Nephrin, podocin and WT1 gene expression levels were unaffected by the Hsf-1 carrier status. TTRV30M deposition was associated with increased PFW and GBM thickness.

CONCLUSIONS

Under the effect of Hsf-1 hemizygosity, TTRV30M deposition has deleterious effects on GBM thickness, PFW and slit diaphragm composition, without affecting nephrin and podocin gene expression.

Losartan affects glomerular AKT and mTOR phosphorylation in an experimental model of type 1 diabetic nephropathy

The AKT-mTOR pathway is activated in diabetic nephropathy. Renin-angiotensin system modulators exert beneficial effects on the diabetic kidney. We explored the action of losartan on AKT-mTOR phosphorylation in glomeruli and podocytes. Diabetes mellitus was induced to Sprague-Dawley rats by streptozotocin. Five months later, the rats were commenced on losartan and euthanized 2 months later. Kidneys were processed for immunofluorescence studies. Glomeruli were isolated for Western blot analysis. Diabetes increased activated forms of AKT and mTOR both in glomeruli and podocytes. In diabetic rats, losartan decreased phosphorylated/activated forms of AKT (Thr308) and mTOR (Ser2448) in glomeruli but decreased only activated mTOR in podocytes. However, in both glomeruli and podocytes of healthy animals, an inverse pattern was evident. In conclusion, a new body of evidence indicates the differential activation of AKT-mTOR in glomeruli and podocytes of healthy and diabetic animals in response to losartan.

Blocking glomerular immunoglobulin deposits in a mouse model of lupus nephritis on indirect immunofluorescence with the use of Fab fragments

One of the most characterized models of murine lupus nephritis is the [NZB×NZW] F1 female hybrid. Extended glomerular IgG deposits may pose an obstacle in studying molecules of interest via indirect immunofluorescence due to secondary antibodies non-specific binding to deposited IgG molecules. Application of Fab fragments may mitigate non-specific interactions in this mouse model. Specifically we provide evidence that blocking paratopic interactions of secondary antibodies with indigenous glomerular IgG deposits is possible. However the blocking effect seems to be related to the species used for secondary antibody production. Increased secondary antibody host species homology with the mouse could make blocking of non-specific binding via the use of Fab fragments impossible in this mouse model.

Rapamycin induced ultrastructural and molecular alterations in glomerular podocytes in healthy mice

BACKGROUND

In the normal kidney, rapamycin is considered to be non-nephrotoxic. In the present study, we investigated whether rapamycin is indeed non-nephrotoxic by examining the ultrastructural and molecular alterations of podocytes in healthy mice.

METHODS

Balb/c mice were given three different intraperitoneal doses of rapamycin for 1 week (dose model)-low-dose group: 1 mg/kg/day, intermediate-dose (ID) group: 1.5 mg/kg/day and high-dose (HD) group: 3 mg/kg/day; four mice in each group. An ID of rapamycin was also given for three different periods (time model): 1, 4 and 8 weeks; four mice were in each group. Mice treated with dimethyl sulphoxide served as controls. Body weight was measured weekly. Renal function was assessed by serum creatinine at the time of sacrifice. For estimation of albuminuria, 24-h urine collections were performed before treatment and weekly thereafter. Glomerular content of nephrin, podocin, Akt and Ser473-phospho-Akt was estimated by western blot and immunofluorescence. Nephrin and podocin messenger RNA (mRNA) were measured by real-time polymerase chain reaction. Mean podocyte foot process width (FPW) was measured by electron microscopy.

RESULTS

Urine albumin levels increased in the HD and 4-week groups. Renal function was modestly deteriorated in the HD group. The mean FPW increased in a dose-dependant manner at Week 1, further deteriorated at Week 4 and finally improved at Week 8. Nephrin and podocin mRNA levels showed a significant decrease at Week 1 and were restored at Week 4 and 8. Nephrin and podocin protein levels were reduced at Week 4 and recovered at Week 8. Ser473-phospho-Akt significantly increased in all rapamycin-treated groups.

CONCLUSIONS

Rapamycin induced significant ultrastructural and molecular alterations in podocytes in association with albuminuria. These alterations happened early during treatment and they tended to improve over an 8-week treatment period.

Low serum testosterone, arterial stiffness and mortality in male haemodialysis patients

BACKGROUND

In the general population, accumulating data support a link between low testosterone levels and mortality by all causes, but especially by cardiovascular disease (CVD). Also, accelerated arterial stiffness has been recognized as an important cardiovascular risk factor. Here, we explored the association between testosterone levels and risk of death in male haemodialysis (HD) patients, whose arterial system is characterized by generalized stiffening.

METHODS

In this three-centre prospective observational study, 111 male HD patients after completion of baseline assessment, including measurement of male sex hormones and pulse wave velocity (PWV), were followed up for CVD and all-cause mortality.

RESULTS

Of the 111 patients studied, 54 were found with and 57 without testosterone deficiency, defined as testosterone levels <8 nmol/L. During a median follow-up period of 37 months, 49 deaths occurred, 28 (57%) of which were caused by CVD. Testosterone deficiency patients had increased CVD and all-cause mortality {crude hazard ratio: 3.14 [95% confidence interval (CI), 1.21-8.16] and 3.09 (95% CI, 1.53-6.25), respectively}, even after adjustment for age, body mass index, serum albumin and C-reactive protein, prevalent CVD and HD vintage. The association of testosterone with CVD mortality, but not with all-cause mortality, was lost after adjusting for PWV, an index of arterial stiffness. Testosterone levels were inversely related to PWV (r = -0.441; P < 0.001).

CONCLUSION

We showed that testosterone deficiency in male HD patients is associated with increased CVD and all-cause mortality and that increased arterial stiffness may be a possible mechanism explaining this association.

Membranous nephropathy and lupus-like syndrome after hematopoietic cell transplantation: a case report

INTRODUCTION

The kidney is increasingly recognised as a target organ of chronic graft-versus-host disease after hematopoietic cell transplantation in the context of the development of the nephrotic syndrome. Chronic graft-versus-host disease is associated with autoimmune phenomena similar, but not identical, to those observed in various rheumatologic disorders, implicating autoimmunity as an important component of the disease.

CASE PRESENTATION

We report the case of a 57-year-old Caucasian man who developed the nephrotic syndrome due to membranous nephropathy in association with recurrent chronic graft-versus-host disease, along with a lupus-like syndrome manifested with pancytopenia, hair loss, positive anti-DNA antibodies and sub-epithelial and mesangial immune deposits. To the best of our knowledge, this is the first case reported in the literature. The nephrotic syndrome subsided soon after he was treated with a short course of cyclosporin with steroids. Unfortunately he died seven months later due to a relapse of leukemia.

CONCLUSIONS

Our case report confirms the notion that chronic graft-versus-host disease is characterized by the appearance of autoimmune phenomena similar, but not identical, to those seen in autoimmune diseases. The decision for more immunosuppression has to be weighed against the need for preservation of the graft versus leukemia phenomenon.

Biopsy-proven resolution of renal light-chain deposition disease after autologous stem cell transplantation

Light-chain deposition disease (LCDD) is caused by an underlying clonal plasma cell dyscrasia in which monoclonal immunoglobulin light chains (LCs) are deposited in tissues, resulting in varying degrees of organ dysfunction. Autologous stem cell transplantation (ASCT) has been reported to stabilize renal function in patients with LCDD, but currently, no evidence of histopathologic resolution of LC deposition after ASCT exists. We present a patient, with severe renal dysfunction due to LCDD, who was treated with high-dose melphalan and ASCT that resulted in a significant and extended period of improved renal function. Four years after the initial improvement, the patient developed nephrotic range proteinuria, without any evidence of relapse of the plasma cell dyscrasia. At that time, a repeat renal biopsy showed complete resolution of LC depositions and development of extensive glomerulosclerosis, thus explaining proteinuria. To the best of our knowledge, this is the first report of a biopsy-proven resolution of renal LCDD following ASCT. A timely application of ASCT should be considered in LCDD to prevent deterioration of renal function in the long run.