Is tuberculosis (TB) more commonly associated with nephrotic syndrome or nephritic syndrome?

Tuberculosis is More Commonly Associated with Nephrotic Syndrome Than Nephritic Syndrome

Tuberculosis (TB) is more strongly associated with nephrotic syndrome, particularly membranous nephropathy, compared to nephritic syndrome, based on available evidence and clinical guidelines.

Relationship Between TB and Kidney Disease

TB and Nephrotic Syndrome

• TB is recognized as an important infectious cause of secondary glomerular diseases that present with nephrotic syndrome 1
• Screening for TB is specifically recommended in patients with glomerular disease and nephrotic syndrome according to KDIGO guidelines 1
• Practice Point 1.8.2 from KDIGO 2021 explicitly recommends screening for tuberculosis in clinically appropriate patients with glomerular diseases 1

Pathophysiological Mechanisms

• The association between TB and nephrotic syndrome appears to be immunologically mediated:
  • TB can trigger immune complex formation and deposition in glomeruli
  • T-cell dysfunction in TB may contribute to the development of nephrotic syndrome 1
  • Evidence suggests a primary T-cell disorder may be responsible in minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS), which are common causes of nephrotic syndrome 1

Specific Nephrotic Lesions Associated with TB

• Membranous nephropathy is the most commonly reported glomerular lesion associated with TB 2, 3
• Case reports document membranous nephropathy with granulomatous interstitial nephritis in TB patients 2
• Minimal change disease and amyloidosis have also been reported in association with TB

TB and Nephritic Syndrome

• While TB can occasionally cause rapidly progressive glomerulonephritis (RPGN) with nephritic features, this is much rarer 4
• Only a few case reports document crescentic glomerulonephritis associated with TB 4
• Tubulointerstitial nephritis is more common than glomerulonephritis with nephritic features in TB patients 5

Risk Factors and Screening Recommendations

High-Risk Populations

• Patients with chronic renal failure who are on hemodialysis have a TB risk 10-25 times greater than the general population 1
• Patients with nephrotic syndrome are at increased risk for infections including TB due to:
  • Loss of immunoglobulins in urine
  • Malnutrition from protein loss
  • Immunosuppressive treatments used for nephrotic syndrome 1

Screening Recommendations

• KDIGO guidelines specifically recommend TB screening in patients with glomerular disease 1
• Screening is particularly important before initiating immunosuppressive therapy for nephrotic syndrome 1
• Patients with nephrotic syndrome receiving high-dose corticosteroids or other immunosuppressants should be considered for prophylactic treatment 1

Management Considerations

• When TB is identified in patients with nephrotic syndrome:
  • Anti-TB therapy should be initiated promptly
  • Renal function and proteinuria should be monitored closely
  • In some cases, corticosteroids may be needed alongside anti-TB drugs 4, 3
  • Dose adjustments may be necessary for patients with renal insufficiency 1

Clinical Pearls and Pitfalls

• TB-associated glomerular disease may improve with appropriate anti-TB treatment
• Drug-induced nephrotoxicity from anti-TB medications (especially rifampicin) can complicate the clinical picture 6
• TB should be considered in the differential diagnosis of unexplained nephrotic syndrome, especially in endemic regions or high-risk populations
• Renal biopsy may be necessary to distinguish between TB-associated glomerular disease and drug-induced nephrotoxicity

In summary, while TB can be associated with both nephrotic and nephritic syndromes, the evidence more strongly supports its association with nephrotic syndrome, particularly membranous nephropathy. Clinicians should maintain a high index of suspicion for TB in patients presenting with unexplained nephrotic syndrome, especially in high-risk populations.