Background: Nephrotic syndrome (NS) is a rare complication that can occur after haematopoietic stem cell transplantation (HSCT). In patients with membranous nephropathy (MN) who have undergone allogeneic HSCT, a new antigen called protocadherin FAT1 has been identified. Our objective is to present a case series of MN patients after HSCT with a novel antigen-based stratification. Case presentations: Patients who developed full-blown NS due to MN after an HSCT were enrolled in the University Hospital Centre Zagreb study. The first two patients were treated with an HSCT for acute myeloid leukaemia, and both developed NS after cessation of graft versus host disease (GVHD) prophylaxis. The first patient had reduced kidney function, while the second had completely preserved function. Kidney biopsy showed MN with only subepithelial deposits. A thorough examination revealed that there was no secondary cause of the disease. The patients achieved complete remission after undergoing immunosuppression treatment. The third patient underwent HSCT for acute lymphoblastic leukaemia. He developed both acute and chronic GVHD and also experienced avascular hip necrosis. After sixteen years, the patient developed NS with preserved kidney function. The kidney specimen showed membranous nephropathy (MN) with mesangial and subepithelial deposits. Extensive research was conducted, but no secondary cause for the MN was detected. All three cases tested negative for anti-PLA2R antibodies. Biopsy tissue samples were analysed using laser microdissection and tandem mass spectrometry of glomeruli for the detection of different specific antigens. Patients one and two tested positive for FAT1, whereas patient three tested positive for PCSK6. Conclusions: MN can develop at various time intervals after HSCT. Specific antigen testing can help establish the relationship between MN and HSCT. In the future, serum testing for anti-FAT1 antibodies in HSCT patients could be significant in diagnosing FAT1-associated MN, similar to how anti-PLA2R antibodies are significant in diagnosing PLA2R-associated MN.

ANCA-associated vasculitides (AAVs) are rare diseases with a prevalence of less than 200 cases per million persons and an incidence of less than 25 cases per million person-years. Their presenting features can vary from prodromal and nonspecific symptoms to dramatic organ-specific symptoms such as respiratory failure due to diffuse alveolar hemorrhage (DAH) and acute kidney injury (AKI). The latter two are hallmark features of pulmonary-renal syndrome, a potentially fatal condition that necessitates early recognition and treatment in intensive care units (ICUs) and rapid induction of immunosuppressive therapy. Background and case summaries: We described three patients with newly diagnosed AAV during the treatment of critical illness. All patients had DAH and two had AKI. The initial disease severity was extremely high in patients with myeloperoxidase (MPO)-AAV, reaching Sequential Organ Failure Assessment (SOFA) scores of 15 and 14 with predicted mortality ≥ 95.2%. Both patients needed mechanical ventilation, one additional venovenous extracorporeal membrane oxygenation (VV-ECMO), and renal replacement therapy. The patient with proteinase 3 (PR3)-AAV had a less severe disease, SOFA 3, requiring only modest oxygen supplementation and exhibiting only hematuria with normal renal function parameters. Immunosuppressive therapy was initiated during the ICU stay. The patient with the most severe clinical presentation died during the ICU stay because of sepsis, and the other two patients were discharged home. Conclusions: Patients with AAV presenting with pulmonary-renal syndrome necessitate various degrees of organ support. Nevertheless, these patients can be successfully treated in the early, critical stages of the disease and achieve remission.

Background/Objectives: To evaluate the short-term effects of structured physical activity (PA), alone or combined with dietary counselling, in early-stage chronic kidney disease (CKD) patients managed in primary healthcare (PHC). Methods: This non-randomised controlled study was conducted in Croatia from 1 September to 30 November 2025. Ninety adults aged 40–75 years with early-stage CKD were allocated to three groups: structured PA, combined PA and dietary counselling, or control. Interventions included kinesiologist-led PA and, in the combined group, dietitian-led Mediterranean/plant-based counselling. Outcomes included estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (ACR), cardiometabolic risk factors, behavioural measures, quality of life, and sleep quality. Statistical significance was set at p < 0.01. Results: Seventy-eight participants completed follow-up. Changes in eGFR did not differ between groups (p = 0.310). Mean ± standard deviation changes in ACR were −1.10 ± 6.37, −0.86 ± 2.88, and +1.18 ± 3.13 in the PA, combined, and control groups, respectively (p = 0.017, not meeting the prespecified significance threshold). Significant between-group differences were observed for selected patient-reported and PA outcomes, including emotional well-being, energy/fatigue, role limitations due to emotional problems, sedentary time, and total PA (all p ≤ 0.006). Conclusions: Structured PA, with or without dietary counselling, improved PA behaviour and selected patient-reported outcomes in early-stage CKD managed in PHC but did not demonstrate significant short-term effects on kidney-related outcomes. These findings support the feasibility of integrating lifestyle-oriented interventions into PHC as part of integrated CKD care, while larger, longer-term studies are needed.

BACKGROUND. Bortezomib is a well-known frontline therapy for newly-diagnosed multiple myeloma (MM). There have been several case reports about skin vasculitis as a rare side effect of this medicine and one case report about intestinal vasculitis. We are now demonstrating 1st case of a vasculitis affecting skin, intestine and kidney in a single patient. CASE PRESENTATION. Our patient is a 77-year-old woman with MM treated with bortezomib, melphalan and prednisone. She developed leukocytoclastic vasculitis of legs, bloody diarrhea and nephrotic proteinuria. Since the hematological response had been achieved, her condition was understood as a side effect of bortezomib and was completely resolved by discontinuation of the drug and administration of corticosteroids. CONCLUSIONS. These three simultaneous signs suggest a common pathophysiology of the vasculitis manifesting on skin, intestine and kidney also known as Henoch-Schönlein purpura (HSP) and to the best our knowledge is 1st report of this combination of side effects of bortezomib therapy. Clinicians should be aware of this rare, yet possible side effect when treating patients with bortezomib so they could timely recognise it and treat it.