C3 glomerulopathy (C3G)
Description
●Introduction:
➣C3G = rare glomerulopathy due to dysregulation of the alternative complement pathway.
➣Includes: Dense Deposit Disease (DDD) and C3 glomerulonephritis (C3GN).
➣Histology: proliferative GN with MPGN pattern, C3-only staining.
➣Causes: genetic mutations, autoantibodies (C3NeF).
➣Possible environmental trigger = Group A streptococcus; NAPlr protein implicated.
●Discussion:
➣C3G = uncontrolled activation of the alternative complement pathway → C3 deposition is the mechanism.
➣ Causes include environmental triggers, C3Nef autoantibodies, and genetic mutations.
➣ Streptococcus link:
•Noted in PSAGN but also present in certain C3G cases, NAPlr (from Group A streptococcus) binds plasmin, resulting in glomerular injury + complement activation.
•NAPlr and PA persistence after 30 days points to a potential function in C3G.
➣In our case, there was no elevated ASO/ASK or clinical pharyngitis, but we tested positive for NAPlr, suggesting an occult or asymptomatic infection.
➣The prognosis for C3G is generally dismal, with over 50% of DDD and 23% of C3GN progressing to ESRD in less than 28 months.
Nonetheless, instances like this one that were connected to streptococcal infections had favourable kidney outcomes.
➣Reaction to treatment:
• Proteinuria is effectively reduced by steroids, such as mizoribine;
• It is suggested that streptococcus-related C3G may be more responsive to steroids.Certain situations could end on their own.
●Investigations
➣Urinalysis: RBCs 5–10/HPF; 24h proteinuria = 4.4 g/day; 4+ protein, 2+ blood.
➣Blood tests:
•Hypoalbuminemia (2.9 g/dL).
• Low CH50 and low C3 (6 mg/dL).
• Normal C4.
•Hb 7.5 g/dL, a mild form of anaemia.
• Normal creatinine (0.72) and BUN (11.6).
• ASK and ASO are not raised.
➣Renal US/CT imaging shows normal kidneys.
➣ Renal biopsy: 66 glomeruli: thicker walls, lobulation, double contour, and significant mesangial proliferation.
•C3 deposition is the sole immunofluorescence method.
•EM: deposits in the subendothelium and subepithelia.
•C3GN with MPGN pattern is the diagnosis.
➣Special tests:
• Plasmin activity (PA) is NAPlr positive.
• C3Nef is negative.
➣ Course and Treatment
• Began taking 2 mg/kg of prednisolone every other day.
•A combination of dipyridamole, atorvastatin, and losartan.
• There was a notable reduction in proteinuria.
• Proteinuria reappeared after two years of steroid tapering; mizoribine was administered, and proteinuria reduced once again.
•After five years: proteinuria was minimal, renal function was maintained, but C3 was consistently low.
Protocol
● Problems Patients Face: Patients may suffer from a mix of symptoms brought on by glomerular damage, such as oedema, hypertension, proteinuria (protein in urine), and haematuria (blood in urine). If acute presentations are not well treated, they may potentially result in renal insufficiency or possibly develop into chronic kidney disease. Patients may experience persistent or recurring infectious symptoms in infection-triggered instances, and they may react atypically or slowly to usual supportive care.
•Adolescents, the elderly, and those with impaired immune systems are more susceptible to poor renal prognoses because of recurrent or unusual infections. Severe instances may necessitate acute uremia therapies, such as haemodialysis.
● Nursing Management and Interventions
Nursing interventions are essential for handling these issues:
Monitoring: To identify acute kidney damage or progressive oedema early, routinely check vital signs, weight, fluid balance, and urine output.
➣Infection Control: Encourage good hygiene, give antibiotics as directed, and teach patients how to avoid becoming sick, especially if they have a history of staphylococcal or streptococcal infections.
➣Supportive Care: Use prescription drugs and lifestyle recommendations to treat problems such hypertension and fluid overload, promote relaxation, and offer nutritional guidance (low sodium/protein as necessary).
➣ Immunosuppression Management: Assist patients receiving immunosuppressive treatment (like steroids) by keeping an eye out for adverse effects (including infection or glucose intolerance) and providing information on how to take their medications as prescribed.
➣ Psychosocial Support: Provide knowledge and emotional support to increase adherence to long-term treatments, lower anxiety, and foster awareness of the illness.
➣ Renal Biopsy Preparation and Aftercare: To guarantee appropriate healing and early detection of problems, help with renal biopsy operations and post-procedure care in instances where the diagnosis is uncertain or the symptoms are refractory.
Notes
for more details visit 10.1007/s13730-021-00662-2
