Bulgarian specialists flag gaps in lupus nephritis care in first national survey

Lupus nephritis, the kidney inflammation that strikes roughly half of all people living with systemic lupus erythematosus, remains one of the most feared complications of this autoimmune disease. Now, the first national feasibility study in Bulgaria has surveyed the country’s leading rheumatologists and nephrologists to map how the condition is diagnosed, staged and treated in real-world practice, and the picture that emerges is one of competent but uneven care, with wide disagreement over how advanced the disease is by the time patients reach specialists and a strikingly low uptake of biological therapies.

The survey, published in the journal Pharmacia, approached ten leading national specialists drawn from major hospitals in Sofia, Plovdiv and Varna that are authorized by the National Health Insurance Fund to treat lupus nephritis. Seven of the respondents were rheumatologists and three were nephrologists, with four specialists from Sofia, four from Varna and two from Plovdiv. All of the specialists contacted agreed to participate, answering seventeen open-ended questions covering the frequency of lupus nephritis among their lupus patients, standards and duration of care, current treatment protocols, the use of biological therapies, treatment gaps and opportunities for multidisciplinary collaboration. The interviews took place between 25 March and 1 April 2026, and the responses were systematized in an Excel table, reviewed by two researchers, and aggregated using narrative synthesis alongside descriptive statistics.

The numbers reported by the specialists reveal both the scale of the challenge and the uncertainty surrounding it. On average, each specialist diagnosed 29 patients with systemic lupus erythematosus in the last year, with a standard deviation of 30.6, and the specialists estimated a total of approximately 4,050 lupus patients in the country, although the standard deviation of 3,357 attached to that figure underscores how rough these national estimates remain. From those numbers, the specialists derived a current annual diagnosis rate of 0.72 percent, meaning that 29 of the roughly 4,050 estimated patients are newly diagnosed each year. Complications, they said, are common, with lupus nephritis developing in an average of 35 percent of cases, though individual estimates ranged from 5 to 60 percent.

Perhaps the most sobering finding concerns disease staging. The specialists estimated that 44 percent of their lupus nephritis patients, on average, were in stages III, IV or V of the disease, the advanced stages in which most symptoms and complications are already progressing. But the reported percentages varied enormously, from 10 percent to 70 percent, a spread that likely reflects the different points at which rheumatologists and nephrologists encounter patients. Rheumatologists manage the early and systemic aspects of the disease, while nephrologists intervene at advanced stages and perform high-risk procedures such as kidney biopsies.

On the treatment side, the survey found that all diagnosed patients receive therapy, but only about a quarter, an average of 25 percent with responses ranging from 5 to 67 percent, are treated with biological therapy, and the focus there is primarily on patients who are resistant to other treatments. The therapeutic arsenal described by the specialists remains largely conventional: immunosuppressants and corticosteroids, including azathioprine, mycophenolate, cyclophosphamide, cyclosporine, antimalarial medicines, methotrexate, anticoagulants and corticosteroids. Among biological therapies, the specialists mentioned belimumab, rituximab and immunoglobulins. All respondents agreed that treatment guidelines are the main standards for patient therapy and that the current therapy is well tolerated.

The experts were unanimous on one point: timely treatment is essential not only to delay the development of complications but to prevent them altogether. They pointed out that with contemporary medication strategies, approximately 70 to 80 percent of complications could be avoided. That figure gives real weight to the diagnostic delays the survey surfaced, because lupus nephritis causes inflammation of the kidneys that reduces renal function and increases protein loss in the urine, and patients who experience diagnostic delays are at greater risk of developing renal complications. Left untreated, the condition can progress to chronic kidney disease, hypertension and kidney failure, often requiring dialysis or kidney transplantation.

The duration of therapy, the specialists reported, depends on patient response and is relatively long, ranging from two months to at least five years, with the general rule being to continue treatment until patients achieve remission. Once remission is reached, therapy is reduced until the next recurrence of symptoms. Similar rules apply to biological therapy, although its duration may be shorter, at approximately two years until remission. This treat-to-target philosophy, which aims to achieve a defined state of remission or low disease activity, mirrors international practice, and the specialists confirmed that the European League Against Rheumatism recommendations, combining hydroxychloroquine, lower-dose steroids and immunosuppressants such as mycophenolate or cyclophosphamide, with so-called triple therapy adding calcineurin inhibitors or belimumab, guide their approach.

Beyond the kidney, the specialists described a heavy burden of other systemic lupus erythematosus complications, including cardiovascular diseases, neurological, dermatological and joint complications. This aligns with the broader clinical picture of a disease whose symptoms do not always occur simultaneously but develop over time at different stages, producing joint and muscle involvement in approximately 90 percent of patients and nephritis in roughly half. The structural constraints of the Bulgarian system, however, add a distinctly local dimension to these challenges. Only rheumatologists can prescribe biological therapy in Bulgaria, but patient monitoring is the responsibility of both rheumatologists and nephrologists, and plasmapheresis is no longer subsidized by the National Health Insurance Fund, a gap the specialists identified as a major unmet need alongside the demand for new, more specific lupus nephritis therapies, potentially of biological origin.

As potential areas for improvement, the specialists identified the creation of a unified system for diagnosis and therapy, the establishment of coordinated medical centers with sufficient capacity for follow-up of lupus nephritis patients, the development of standardized therapeutic regimens including biopsy when needed, and the prescription of biological therapy through joint committees. They also confirmed, as previous international studies have reported, the need to involve rheumatologists, nephrologists, social workers and other health professionals to control both immune and non-immune risk factors for progressive kidney disease. The authors argue that collaborative efforts in disease management should extend beyond hospital-level cooperation to the national level. Their survey lands amid broader international momentum, as collaborative work among researchers, clinicians, patients and industry advances disease classification, predictive modelling of disease onset and flare risk, innovative clinical trial designs and the discovery of novel biomarkers, all supporting a move toward more personalized care for lupus nephritis.

The study’s findings land against a backdrop of fragmented epidemiological data. The first Bulgarian study, published in 2018, found a lupus nephritis prevalence of 7.68 per 100,000 people, depending on age and sex, while other authors have estimated that systemic lupus erythematosus accounts for 0.06 to 0.08 percent of autoimmune diseases in the country, or approximately 1,000 people diagnosed. The new survey’s estimate of roughly 4,050 patients sits far above that older figure, and the authors note that the study reveals discrepancies in the epidemiological data on systemic lupus erythematosus and lupus nephritis that need to be resolved. Globally, the incidence of the disease varies between 3.7 and 49 per 100,000 person-years in the United States, with prevalence ranging from 48 to 366.6 per 100,000 individuals, and regional figures differing markedly depending on factors such as ethnicity and sex.

The authors are candid about the limitations of their feasibility study, including the limited number of physicians surveyed, though they note that these respondents are specialists at highly experienced national centers for lupus nephritis treatment and key national consultants in both specialties. Differences in treatment practices and physicians’ awareness may well exist at the regional level, and further studies are needed to increase the number of respondents and identify areas for improving coordination of care. Still, as a first national snapshot, the survey establishes a broad overview of the current situation and points toward concrete fixes: early identification protocols, formalized multidisciplinary coordination between rheumatology and nephrology, and restored access to subsidized plasmapheresis. For Bulgarian patients with lupus nephritis, the message from their country’s leading specialists is clear: the treatments exist, the guidelines exist, but the system that connects patients to them, early and consistently, still needs to be built.

Subject of Research: Physician awareness, morbidity and treatment of lupus nephritis in Bulgaria

Article Title: Awareness of specialists about morbidity and treatment of lupus nephritis in Bulgaria: A feasibility study

Article References: Dimitrova, M., Mitkova, Z., Tsvetkova, A., Gueorgiev, S., Boyadzhieva, V., Stoilov, N., & Petrova, G. (2026). Awareness of specialists about morbidity and treatment of lupus nephritis in Bulgaria: A feasibility study. Pharmacia, 73, Article e217485. https://doi.org/10.3897/pharmacia.73.e217485

Image Credits: AI Generated

DOI: 10.3897/pharmacia.73.e217485

Keywords: lupus nephritis, systemic lupus erythematosus, Bulgaria, rheumatology, nephrology, biological therapy, autoimmune disease, kidney disease, treat-to-target, healthcare access, feasibility study, immunosuppressants