In cases of acute or chronic liver failure SBP is one of the main triggers for hepatic encephalopathy, and where there is no other clear causal indication for this, SBP may be suspected.These symptoms can also be the same for a spontaneous fungal peritonitis (SFP) and therefore make a differentiation difficult. Delay of diagnosis can delay antifungal treatment and lead to a higher mortality rate. Causes
SBP is most commonly caused by gram-negative E. coli, followed by Klebsiella. Common gram-positive bacteria identified include species of Streptococcus, Staphylococcus, and Enterococcus. The percentage of gram-positive bacteria responsible has been increasing.A spontaneous fungal infection can often follow a spontaneous bacterial infection that has been treated with antibiotics. The use of antibiotics can result in an excessive growth of fungi in the gut flora which can then translocate into the peritoneal cavity. Although fungi are much larger than bacteria, the increased intestinal permeability resulting from advanced cirrhosis makes their translocation easier. SFP is mostly caused by species of Candida and most commonly by Candida albicans. Pathophysiology
H2 antagonists and proton-pump inhibitors are medications that decrease or suppress the secretion of acid by the stomach. Their use in treating cirrhosis is associated with the development of SBP. Bacterial translocation is thought to be the key mechanism for the development of SBP. Small intestinal bacterial overgrowth which may be implicated in this translocation, is found in a large percentage of those with cirrhosis.
Pyridoxine-dependent epilepsy (PDE) is a rare genetic disorder characterized by intractable seizures in the prenatal and neonatal period. The disorder was first recognized in the 1950s, with the first description provided by Hunt et al. in 1954. More recently, pathogenic variants within the ALDH7A1 gene have been identified to cause PDE. Genetics
PDE is inherited in an autosomal recessive manner and is estimated to affect around 1 in 400,000 to 700,000 births, though one study conducted in Germany estimated a prevalence of 1 in 20,000 births. The ALDH7A1 gene encodes for the enzyme antiquitin or α-aminoadipic semialdehyde dehydrogenase, which is involved with the catabolism of lysine. Treatment
Patients with PDE do not respond to anticonvulsant medications, but seizures rapidly cease with therapeutic intravenous doses of vitamin B6 and remission from seizures are often maintained on daily therapeutic doses of vitamin B6. An optimal dose has not yet been established, but doses of 50–100 mg/day or 15–30 mg/kg/day have been proposed. Importantly, excessive doses of vitamin B6 can result in irreversible neurological damage, and therefore several guidelines recommend between 200 mg (neonates) and 500 mg per day as the maximal daily dose.Despite remission of seizure activity with vitamin B6 supplementation, intellectual disability is frequently seen in patients with PDE. Because the affected enzyme antiquitin is involved in the cerebral lysine degradation pathway, lysine restriction as an additional treatment modality has recently been explored. Studies have been published which demonstrate potential for improved biomarkers, development, and behavior in patients treated with lysine restriction in addition to pyridoxine supplementation.