Background: The diagnosis of chronic kidney disease (CKD) is usually delayed, when significant functional renal impairment has already occurred. The diagnosis is complex and clinical and laboratory investigations play a crucial role. There are well-established markers of CKD – serum creatinine and cystatin C. However, the search for new reliable biomarkers that aid in the assessment of kidney function and predict the evolution of the disease is still in progress. Objective: To investigate the role of serum uromodulin (sUmod) as a marker for early diagnosis of renal impairment in patients with CKD. Materials and Methods: We investigated 70 patients, 28 male and 42 female, mean age 56.53 ± 11.753, with CKD in a prospective observational study. All patients were admitted to the Clinic of Nephrology at the “St. Ivan Rilski” University Hospital between April and November 2019. After obtaining written informed consent, laboratory blood and urine tests, abdominal ultrasound and sUmod investigations were performed in all patients. Results: Plasma uromodulin levels showed decrease with the increasing of the severity of renal impairment. sUmod displayed inverse correlation with serum creatinine (r = -0.467, p < 0.0001), cystatin C (r = -0.430, p < 0.0001) and urea (r = -0.495, p < 0.0001) and a positive correlation with eGFR (r = 0.628, p < 0.0001). Conclusion: The results of our study show that sUmod levels significantly correlate with all established laboratory parameters used for the evaluation of renal impairment. It can be used as a potential early biomarker for CKD diagnosis.

Disseminated superficial actinic porokeratosis (DSAP) is a skin condition that consist of multiple annular, hyperkeratotic lesions. They are usually distributed bilaterally and mostly affect the extremities. DSAPs have a wider distribution than the porokeratosis of Mibelli and usually appears between the age of 40 and 50. Squamous cell carcinoma, Bowen's disease, and basal cell carcinoma that arises in the classical type of porokeratosis of Mibelli is well-documented, but there are not many reported cases of Bowen's disease and basal cell carcinoma arising in DSAP. We present a 77-year-old woman in whom the two-Bowen's disease and Basal cell carcinoma develop in a histologically proven DSAP.

Systemic lupus erythematosus is a chronic, systemic, non-organ-specific autoimmune disease that affects all organs and systems of the human body and is characterized by the production of autoantibodies against nuclear antigens. Its prevalence in Europe reaches 1:2500. It affects mostly women (female : male ratio=9 : 1) in fertile age group (15-45 years). The clinical course of lupus in males is characterized by more aggressive clinical course and the development of serious complications, such as vasculitis, central nervous system involvement, antiphospholipid syndrome, etc. For the period of 7 years (2012-2019) we observed overall 18 male patients with systemic lupus, 11 with biopsy-proven renal involvement and 7 without clinically significant renal disease (proteinuria < 0.5 g/24 h., no erythrocyturia/cylindruria, normal renal function), mean age at the diagnosis 39.6 +/- 12.3 years. All patients received pathogenetic treatment (corticosteroids + cytotoxic agents). Three had secondary antiphospholipid syndrome, 1 – inflammatory bowel disease, 1 – seronegative spondyloarthropathy. Three had type 2 diabetes. The authors discuss the clinical, immunological and histological characteristics and the therapeutic approach in males with systemic lupus.

A 47-year-old female patient with active Systemic lupus erythematosus (SLE) - skin, joint, hematological, and renal involvement was admitted for rapidly progressive renal failure at the background of very high anti-dsDNA and pANCA antibodies. Active pathogenetic treatment was started pulse therapy with methylprednisolone, intravenous immunoglobulins (IVIG) and cyclophosphamide, blood transfusions were performed, symptomatic treatment with infusions ad diuretic was initiated. Due to progression of renal failure with volume overload and increase in urea and creatinine levels renal-replacement therapy was initiated. The patient developed E. faecalis and E. durans sepsis with disseminated intravascular coagulation and ground-glass-type lung changes and the condition further deteriorated to fatal multiorgan failure. The authors discuss the role of pANCA antibodies in SLE with renal and lung involvement.

In December 2019 a newly described single-stranded coronavirus, later named SARS-CoV-2, started its expansion around the world and subsequently caused a global pandemic, affecting the lives of millions of people worldwide. SARS-CoV-2 can bind multiple receptors on different cells and thus invade many target organs, including the respiratory and gastrointestinal mucous membranes, lungs, central nervous system, heart, etc. This virus can affect the kidney tissue both directly and as a consequence of other organ involvement or of the treatment administered, causing acute kidney injury and leaving long term squeals that worsen the prognosis. We describe three patients with acute kidney injury and subsequent acute renal failure at the background of coronaviral infection.