What are the complications of Minimal change disease?
The complications of Minimal change disease are those of nephrotic syndrome or are related to the toxicities of the treatments used. For the patient with frequent relapses, there is a delicate trade-off between the complications of the disease and the side effects of the medications.
Minimal change disease may have life-threatening complications. These include the risks of overwhelming infection, thromboembolic phenomenon, and the cardiovascular complications related to hyperlipidemia.
The cause of the increased risk of infection is multifactorial but is in part related to loss of opsonizing factors in the urine.
Opsonizing factors are particularly important in defense against encapsulated bacteria such as Pneumococcus and Haemophilus influenzae. Another risk factor for infection in the patient with Minimal change disease is the frequent occurrence of hypogammaglobulinemia in these patients, especially during episodes of relapse.
There is an increased risk of serious bacterial infections when the plasma IgG levels fall to less than 400 mg/dL and a very increased risk when levels fall to less than 200 mg/dL.
In a patient with low IgG levels and sepsis, or in those patients with chronic hypogammaglobulinemia, intravenous gamma globulin may be used.
Thromboembolism may be seen in patients with Minimal change disease, more commonly in the adult with MCD than in the child with Minimal change disease.
Children are more prone to sagittal sinus thrombosis, pulmonary artery thrombosis, or inferior vena caval thrombosis, whereas adults with Minimal change disease are more prone to deep vein or renal vein thrombosis.
The hypercoagulable state in MCD results from several factors, including increased clotting factor synthesis (fibrinogen, II, V, VII, IX, X, XIII), urinary losses of anticoagulants (antithrombin III), platelet abnormalities (thrombocytosis, increased aggregability), hyperviscosity, and hyperlipidemia.
Patients in a severe relapse have an increased risk of developing acute kidney injury secondary to decreased kidney perfusion and edema of the kidney interstitium.
Acute kidney injury is usually reversible in this setting. Intravenous albumin therapy should not be given during an episode of acute kidney injury because of the risk of pulmonary edema.
Chronic hyperlipidemia in the patient with Minimal change disease can lead to the accelerated development of arteriosclerosis.
