Pulmonary-Renal Syndrome with Negative ANCAs and Anti-GBM Antibody

Pulmonary Renal Syndrome in ANCA-Negative Vasculitis

Below we highlight a rare case of anti-neutrophil cytoplasmic antibody (ANCA)-negative vasculitis, unique in its own right, as the diagnosis was hard to make and the respiratory decline rapid, with the patient going from a 23% fraction of inspired oxygen (FiO2) on admission to 100% FiO2 within four days for what was initially presumed to be community-acquired pneumonia. Precise data on the incidence or prevalence of ANCA-associated vasculitis are lacking. However, a 20-year population-based study in the United States found that, of 58 incident cases, 9% were ANCA-negative. We present the case of a 69-year-old Egyptian male with worsening shortness of breath who was found to have elevated inflammatory markers and an ANCA-negative panel and was later diagnosed with ANCA-negative vasculitis. By highlighting this case, we aim to increase awareness and point out the need to keep the disease high on the list of differential diagnoses in order to allow for timely intervention. Though there isn't a lot of data available on definitive treatment or the disease itself, there are studies that point to rituximab, cyclophosphamide, plasmapheresis, and hemodialysis as useful interventions for treatment.

A Case of Seronegative Pulmonary-renal Syndrome: Diagnostic and Therapeutic Challenge

BACKGROUND: Pulmonary renal syndrome (PRS) is not a single entity but is caused by varied etiologies, including anti-neutrophil cytoplasmic antibody (ANCA), associated small vessel vasculitis (such as Wegener’s granulomatosis, microscopic polyangiitis, and Churg-Strauss vasculitis), Goodpasture’s syndrome, systemic lupus erythematosus, Henoch-Schonlein purpura, cryoglobulinemia, and rare causes such as druginduced vasculitis and subacute endocarditis. CASE REPORT: We report a case of a 51-year-old man who was referred to our hospital with a 2-month history of breathing difficulties, mild hemoptysis, and deteriorated renal function with a serum creatinine of 269 μmol/L. Serological testing was negative for anti-neutrophil cytoplasmic antibody (ANCA) and anti-glomerular basement membrane (GBM) antibody, and also all cultures, including blood and urine, remained negative. In the renal biopsy, not linear deposition of IgG along the GBM and crescents at varying stages with extracapillary glomerulonephritis emphasizes the possibility of a double-seronegative pulmonary renal syndrome. Regarding therapeutic dilemmas, on the 3rd day of hospitalization, we initiated immunosuppression with cyclophosphamide and corticosteroids as well as plasma exchange (5 treatments). Under immunosuppressive therapy and plasma exchange, the patient’s status continually improved; there was no pulmonary bleeding, but the serum creatinine remained high and renal function remained in stage 4 chronic kidney disease. Four weeks later, he was hospitalized again, and we faced a new therapeutic dilemma because of the rapid relapse during immunosuppressive therapy and renal function deterioration that required hemodialysis treatment. Despite repeatedly negative results for anti-GBM and ANCA, initial immunosuppressive therapy with plasma exchange (9 treatments) was included again. The patient was discharged 30 days after admission in a stable general condition, with the maintenance immunosuppressive therapy with mycophenolate mofetil and hemodialysis 3 times/week. After 24 months, we have received information from the hemodialysis center that he is on regular hemodialysis and that he is in good condition. CONCLUSION: We think that in this atypical case, intensive plasma exchange and immunosuppressive therapy are crucial in the early stage and maintenance therapy is necessary for vasculitis in remission. This reported case has important clinical implications because pulmonary-renal syndrome with negative ANCAs and anti-GBM antibodies is extremely rare and no treatment recommendations have been established yet.

Pulmonary renal syndrome: A case report of diffuse alveolar hemorrhage in association with ANCA negative pauci-immune glomerulonephritis

RATIONALE

Pulmonary renal syndrome (PRS) is a term most commonly used to describe a combination of glomerulonephritis and pulmonary hemorrhage as a manifestation of a multisystem autoimmune disease. It is usually associated with ANCA vasculitis and anti-GBM disease. Diffuse alveolar hemorrhage in a patient with ANCA and anti-GBM negative pauci-immune glomerulonephritis is rare and optimal management is unknown.

PATIENT CONCERNS

An 85-year-old man with hypertension, diabetes mellitus, prostate cancer and recently diagnosed pauci-immune necrotizing glomerulonephritis presented to our emergency department with worsening dyspnea and pedal edema for several days. Clinical presentation and radiological studies were suggestive of fluid overload but he developed worsening respiratory failure despite hemodialysis.

DIAGNOSES

Bronchoscopy confirmed diffuse alveolar hemorrhage. ANCA and anti-GBM antibodies were negative. The patient was diagnosed with pulmonary renal syndrome - diffuse alveolar hemorrhage in the setting of ANCA and anti-GBM negative pauci-immune glomerulonephritis.

INTERVENTIONS

Patient was started on intravenous pulse steroids, cyclophosphamide and received seven sessions of plasmapheresis.

OUTCOMES

There was an improvement in patient's respiratory status and repeat bronchoscopy at the end of treatment did not show diffuse alveolar hemorrhage.

LESSONS

Pauci-immune crescentic necrotizing glomerulonephritis is usually associated with the presence of ANCA, however, ANCA may be absent in 10% of these cases. Immunosuppression is the mainstay of treatment for ANCA and anti-GBM associated PRS. This case highlights the importance of immunosuppression and plasmapheresis in patients with ANCA negative vasculitis due to presence of unidentified serum antibodies. If left untreated, these patients can have a fulminant course with high mortality ranging from 25 to 50%.

A Rare Clinical Course of Seronegative Pulmonary-Renal Syndrome

Purpose. Pulmonary-renal syndrome (PRS) is characterized by diffuse alveolar hemorrhage and rapidly progressive glomerulonephritis mainly due to autoimmune etiologies. Seronegative PRS is a challenging entity to the clinician, since early diagnosis may be missed leading to delayed appropriate treatment. Materials and Methods. We present the clinical course of a 77-year-old patient who was admitted under the suspected diagnosis of pneumogenic sepsis and septic renal failure with fever, dyspnea, and elevated CRP levels. The diagnosis of pulmonary-renal syndrome was initially missed because of the absence of autoantibodies in all serological findings. Results. Despite delayed initiation of immunosuppressive therapy and a prolonged period of dialysis and extracorporeal membrane oxygenation the patient recovered well and was released to a rehabilitation center with nearly normalized creatinine levels. The diagnosis of PRS was established by renal biopsy. Conclusion. This case illustrates the important differential diagnosis of seronegative pulmonary-renal syndrome in patients with pulmonary and renal impairment.