Differential Diagnosis for Neutrophilia and Rapidly Progressing Glomerulonephritis

Single Most Likely Diagnosis

• Post-Streptococcal Glomerulonephritis (PSGN): This condition is a common cause of rapidly progressing glomerulonephritis, especially following a streptococcal infection. Neutrophilia can be present due to the underlying infection or the inflammatory response in the kidneys.

Other Likely Diagnoses

• Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: Conditions like Granulomatosis with Polyangiitis (GPA) or Microscopic Polyangiitis (MPA) can cause both neutrophilia due to systemic inflammation and rapidly progressing glomerulonephritis due to the vasculitic process affecting the kidneys.
• Infectious Endocarditis: This condition can lead to glomerulonephritis due to immune complex deposition and neutrophilia as a response to the infection. The renal involvement can sometimes present as rapidly progressing glomerulonephritis.
• Lupus Nephritis: Systemic Lupus Erythematosus (SLE) can cause both neutrophilia and rapidly progressing glomerulonephritis, especially in the context of a lupus flare.

Do Not Miss Diagnoses

• Wegener's Granulomatosis (now part of ANCA-Associated Vasculitis): Although included under ANCA-associated vasculitis, it's crucial to specifically consider this due to its potential for severe and rapid progression, including renal failure and respiratory involvement.
• Goodpasture Syndrome: An autoimmune disease causing glomerulonephritis and pulmonary hemorrhage, characterized by antibodies against the glomerular basement membrane. It's less common but critical to diagnose early due to its severe prognosis if untreated.

Rare Diagnoses

• IgA Nephropathy with Rapid Progression: While IgA nephropathy is a common cause of glomerulonephritis, rapid progression is less typical. However, it can occur and should be considered, especially in the absence of a clear infectious or autoimmune cause.
• Henoch-Schönlein Purpura (HSP) Nephritis: HSP can cause glomerulonephritis and is characterized by purpura, arthritis, abdominal pain, and renal involvement. Neutrophilia can be present due to the systemic inflammatory nature of the disease.
• Cryoglobulinemic Glomerulonephritis: This condition, associated with cryoglobulins (proteins that precipitate from blood at cold temperatures), can cause rapidly progressing glomerulonephritis and is often associated with hepatitis C infection or other chronic infections/inflammatory conditions.