Syphilis as the great mimicker: A case of full-house pattern membranous nephropathy.

Syphilis is a known cause of membranous nephropathy. We describe a case of a patient presenting with nephrotic syndrome whose renal biopsy demonstrated a 'full house' immunohistochemical pattern with positive IgG, IgM, C1q, IgA, C3c, and C4d staining. He was treated with immunosuppressive agents for minimal change nephropathy and subsequently class V lupus nephritis, before syphilis infection was confirmed. Following treatment with a single dose of intramuscular benzathine penicillin there was complete and rapid resolution of nephrotic syndrome. With progressive rising incidence in the western world, syphilis is an important and under-recognised differential diagnosis in cases of nephrotic syndrome.

Immune-related acute kidney injury in Australian non-small cell lung cancer patients: Real-world results.

BACKGROUND: The use of immune checkpoint inhibitors has altered therapeutic paradigms in NSCLC. However, they may cause immune-related toxicities, including acute kidney injury (irAKI), especially when combined with nephrotoxic agents. We investigated the incidence, management and outcomes of AKI in Australian NSCLC patients. METHODS: Medical records from a cancer centre registry were reviewed. AKI was defined and graded on absolute creatinine rise, or rise above baseline. Fishers exact test compared proportions. The Kaplan-Meier method estimated survival, and multiple logistic regression tested for risk factors. RESULTS: Of 449 patients who underwent immunotherapy from 2013 to 2021, the median age was 65 years and 61% were male. Metastatic disease was present in 68% at diagnosis, the remainder had stage Ia-III disease; 70% had adenocarcinoma; and 17% had EGFR mutations. AKI was identified in 65 patients (14.5%) of which 19 were irAKI (4.2%). Within irAKI patients, eleven (58%) had other immune-related adverse events. Median time to irAKI onset was 4 months (IQR 4-6). Seventeen (89%) patients had AKI stage 1 or 2; two had stage 3. Eleven patients developed chronic kidney disease; none required renal replacement therapy. Kidney biopsies demonstrated acute interstitial nephritis (n = 3), acute tubular necrosis (n = 1) and anti-phospholipase A2 receptor negative membranous glomerulonephritis (n = 1). Five patients were rechallenged with immunotherapy; two had recurrent irAKI. The median overall survival for those with irAKI was not reached versus 12 months with no irAKI (HR 0.35, 95 %CI 0.20-0.60, p = 0.01). Risk factors for irAKI included having an additional, non-renal irAE (OR 6.21, 95 %CI 2.35-17.26, p ≤ 0.01); immunotherapy combined with other cancer therapies (OR 5.62, 95 %CI 2.08-16.20, p ≤ 0.01); and ECOG performance status > 1 (OR 4.39 (95 %CI 1.11-14.90, p = 0.02) CONCLUSIONS: The incidence of irAKI was similar to the published literature. Renal recovery was poor, however survival was not compromised. Improved diagnostic and therapeutic strategies for irAKI would benefit this population.

Outcomes following parathyroidectomy for secondary hyperparathyroidism in patients with chronic kidney disease: a single-centre study.

BACKGROUND: Surgical parathyroidectomy may be required for severe and refractory secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD). Parathyroidectomy is associated with long-term survival benefit despite an increase in short-term morbidity and mortality. Global variation in practice exists, with limited Australian data on outcomes following parathyroidectomy. AIM: To evaluate clinical outcomes of patients with chronic kidney disease undergoing surgical parathyroidectomy for secondary hyperparathyroidism. METHODS: We conducted a retrospective study of patients who underwent parathyroidectomy for SHPT between January 2010 and December 2019 at a single tertiary referral centre in Melbourne, Australia. Biochemical markers and medications were assessed 12 months pre- and post-surgery. Clinical outcomes, including hospital readmission, cardiovascular events and mortality were assessed following surgery. RESULTS: During the 10-year study period, 129 patients underwent parathyroidectomy for SHPT (mean age 50.7 ± 15 years; 109 (85%) on dialysis). Significant immediate post-operative complications were seen in eight (6%) patients, requiring admission to the intensive care unit (n = 6) or return to theatre (n = 2). Within the first 6 months, 24 (19%) patients required hospital readmission. Within 12 months post-parathyroidectomy, 100 (78%) and 103 (80%) patients experienced at least one episode of hypercalcaemia (corrected calcium >2.6 mmol/L) or hypocalcaemia (corrected calcium <2.1 mmol/L) respectively. Over a 12-month period, there were six (5%) deaths and eight (6%) patients experienced a major cardiovascular event. CONCLUSION: Significant fluctuations in serum calcium levels are common post-parathyroidectomy; however, long-term morbidity and mortality in our cohort were lower than previously reported, highlighting that parathyroidectomy in a carefully selected cohort is safe for severe SHPT refractory to medical treatment.

Changes in bone microarchitecture following parathyroidectomy in patients with secondary hyperparathyroidism.

BACKGROUND: Secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD) has a significant effect on bone, affecting both trabecular and cortical compartments. Although parathyroidectomy results in biochemical improvement in mineral metabolism, changes in bone microarchitecture as evaluated by high-resolution imaging modalities are not known. Magnetic resonance imaging (MRI) provides in-depth three-dimensional assessment of bone microarchitecture, as well as determination of mechanical bone strength determined by finite element analysis (FEA). METHODS: We conducted a single-centre longitudinal study to evaluate changes in bone microarchitecture with MRI in patients with SHPT undergoing parathyroidectomy. MRI was performed at the distal tibia at baseline (time of parathyroidectomy) and at least 12 months following surgery. Trabecular and cortical topological parameters as well as bone mechanical competence using FEA were assessed. RESULTS: Fifteen patients with CKD (12 male, 3 female) underwent both MRI scans at the time of surgery and at least 12 months post-surgery. At baseline, 13 patients were on dialysis, one had a functioning kidney transplant, and one was pre-dialysis with stage 5 CKD. Seven patients received a kidney transplant following parathyroidectomy prior to follow-up MRI. MRI parameters in patients at follow up were consistent with loss in trabecular and cortical bone thickness (p = 0.006 and 0.03 respectively). Patients who underwent a kidney transplant in the follow-up period had reduction in trabecular thickness (p = 0.05), whereas those who continued on dialysis had reduction in cortical thickness (p = 0.04) and mechanical bone strength on FEA (p = 0.03). CONCLUSION: Patients with severe SHPT requiring parathyroidectomy have persistent changes in bone microarchitecture at least 12 months following surgery with evidence of ongoing decline in trabecular and cortical thickness.

Bone microarchitecture in patients undergoing parathyroidectomy for management of secondary hyperparathyroidism.

BACKGROUND: Secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD) leads to complex bone disease, affecting both trabecular and cortical bone, and increased fracture risk. Optimal assessment of bone in patients with CKD is yet to be determined. High-resolution magnetic resonance imaging (MRI) can provide three-dimensional assessment of bone microarchitecture, as well as determination of mechanical strength with finite element analysis (FEA). METHODS: We conducted a single-centre, cross-sectional study to determine bone microarchitecture with MRI in CKD patients with SHPT undergoing parathyroidectomy. Within two weeks of surgery, MRI was performed at the distal tibia and biochemical markers of SHPT (parathyroid hormone [PTH] and alkaline phosphatase [ALP]) were collected. Trabecular and cortical topological parameters as well as bone mechanical competence using FEA were assessed. Correlation of MRI findings of bone was made with biochemical markers. RESULTS: Twenty patients with CKD (15 male, 5 female) underwent MRI at the time of parathyroidectomy (16 on dialysis, 3 with functioning kidney transplant, one pre-dialysis with CKD stage 5). Median PTH at the time of surgery was 138.5 pmol/L [39.6-186.7 pmol/L]. MRI parameters in patients were consistent with trabecular deterioration, with erosion index (EI) 1.01 ±â€¯0.3, and trabecular bone volume (BV/TV) 10.8 ±â€¯2.9%, as well as poor trabecular network integrity with surface-to-curve ratio (S/C) 5.4 ±â€¯2.3. There was also evidence of reduced cortical thickness, with CTh 2.698 ±â€¯0.630 mm, and FEA demonstrated overall poor bone mechanical strength with mean elastic modulus of 2.07 ±â€¯0.44. CONCLUSION: Patients with severe SHPT requiring parathyroidectomy have evidence of significant changes in bone microarchitecture with trabecular deterioration, low trabecular and cortical bone volume, and reduced mechanical competence of bone.

Vascular calcification in skin and subcutaneous tissue in patients with chronic and end-stage kidney disease.

BACKGROUND: Vascular calcification (VC) is well described in large- and medium-sized vessels in patients with chronic kidney disease (CKD), especially in those with end-stage kidney disease (ESKD) on dialysis. Medial calcification is particularly prevalent in this population and contributes to arterial stiffness and increased cardiovascular mortality and morbidity. Apart from in the setting of calciphylaxis, few studies have assessed skin and subcutaneous calcification and associations with abnormalities of bone and mineral metabolism in patients with CKD. METHODS: We performed a single-centre observational study to evaluate incisional skin tissue samples from three anatomical sites in patients with different stages of CKD undergoing elective surgery. We compared these samples to skin samples of a control cohort without CKD. Staining for calcification was performed with von Kossa method. A subgroup of skin samples were assessed by RT-PCR for upregulation of pro-calcific gene transcripts for tissue non-specific alkaline phosphatase (TNAP) and Runt-related transcription factor 2 (RUNX2). RESULTS: Forty-five patients were evaluated, 34 with CKD (including ESKD) and 11 control patients. VC was identified in 15 skin samples (13 CKD/ESKD and 2 controls). VC was present in the dermal and subcutaneous tissues of the neck, abdomen and arm samples. Two different histological types of VC were identified: speckled medial calcification and internal elastic lamina calcification. Presence of perieccrine calcification was identified in 14 samples, 10 with concurrent VC. There were no significant differences in serum parathyroid hormone, phosphate or calcium in patients with or without VC. Expression of TNAP or RUNX2 was not increased in samples from patients with ESKD or those with histological evidence of calcification. CONCLUSION: This study reports the novel finding of dermal and subcutaneous calcification in multiple anatomical locations in 38% of patients with advanced CKD/ESKD undergoing elective surgery but free from calciphylaxis.