Prolidase deficiency: case reports of two Argentinian brothers

Topical Insulin Application in the Management of Resistant Leg Ulcers in a Patient With Prolidase Deficiency: A Case Report

Leg ulcers are a significant cause of morbidity and mortality and can be caused by vascular, neuropathic, infectious, and traumatic factors, as well as rare metabolic diseases like prolidase deficiency. Despite various wound care methods and systemic treatments, managing ulcers can be challenging. This case presents a male patient with prolidase deficiency for 35 years whose leg ulcers were resistant to standard treatments such as wound dressings, topical treatments, and hyperbaric oxygen therapy. Considering the ulcers' resistant nature, we applied topical insulin to ulcers as an add-on therapy and observed clinical improvement. In this case, we want to emphasize the potential of insulin as a supplementary treatment agent in prolidase deficiency-induced ulcer treatment.

Quantitative analysis of the natural history of prolidase deficiency: description of 17 families and systematic review of published cases

PURPOSE

Prolidase deficiency is a rare inborn error of metabolism causing ulcers and other skin disorders, splenomegaly, developmental delay, and recurrent infections. Most of the literature is constituted of isolated case reports. We aim to provide a quantitative description of the natural history of the condition by describing 19 affected individuals and reviewing the literature.

METHODS

Nineteen patients were phenotyped per local institutional procedures. A systematic review following PRISMA criteria identified 132 articles describing 161 patients. Main outcome analyses were performed for manifestation frequency, diagnostic delay, overall survival, symptom-free survival, and ulcer-free survival.

RESULTS

Our cohort presented a wide variability of severity. Autoimmune disorders were found in 6/19, including Crohn disease, systemic lupus erythematosus, and arthritis. Another immune finding was hemophagocytic lymphohistiocytosis (HLH). Half of published patients were symptomatic by age 4 and had a delayed diagnosis (mean delay 11.6 years). Ulcers were present initially in only 30% of cases, with a median age of onset at 12 years old.

CONCLUSION

Prolidase deficiency has a broad range of manifestations. Symptoms at onset may be nonspecific, likely contributing to the diagnostic delay. Testing for this disorder should be considered in any child with unexplained autoimmunity, lower extremity ulcers, splenomegaly, or HLH.

Topical tacrolimus therapy in the management of lower extremity ulcers due to prolidase deficiency

Prolidase deficiency is a rare autosomal recessive disorder characterized by cutaneous ulcers, facial dysmorphism, recurrent infections, and intellectual disability. We report a unique case of a 6-year-old boy with prolidase deficiency and Crohn's disease who presented with lower extremity ulcers. Cutaneous ulcers due to prolidase deficiency are historically resistant to treatment, and we report success with the novel use of topical tacrolimus.

A Rare Cause of Lower Extremity Ulcers: Prolidase Deficiency

Prolidase deficiency is an autosomal recessive disorder, which is associated with chronic skin ulcers, a characteristic facial appearance, mental retardation, and recurrent infections. This study describes 4 patients with recurrent leg ulcerations and abnormal facies who were first clinically suspected of prolidase deficiency and then biochemically confirmed. Two siblings and 2 other patients were admitted to our clinic at different times, and they had some common features such as chronic leg and foot ulcers recalcitrant to treatment, consanguineous parents, facial dysmorphism, mental retardation, and widespread telangiectasias. Physical examination and detection of low prolidase level in blood finally led us to the diagnose of ulcers secondary to prolidase deficiency. Prolidase deficiency is a rare genodermatosis and must be considered in the differential diagnosis of recurrent leg and foot ulcers that develop at an early age.

Enalapril stimulates collagen biosynthesis through prolidase-dependent mechanism in cultured fibroblasts

The mechanism of a lower incidence of dermatological manifestations in patients treated with enalapril compared to patients treated with other ACE-inhibitors, e.g., captopril, is not known. The finding that prolidase plays an important role in collagen biosynthesis and that some angiotensin-converting enzyme inhibitors affect prolidase activity led us to evaluate its effect on collagen biosynthesis in cultured human skin fibroblasts. Since insulin-like growth factor (IGF-I) and transforming growth factor beta 1 (TGF-β1) are the most potent stimulators of both collagen biosynthesis and prolidase activity, and prolidase is regulated by β₁ integrin signaling, the effect of enalapril and enalaprilat on IGF-IR, TGF-β1, and β₁ integrin receptor expressions was evaluated. Cells were treated with milimolar concentrations (0.3 and 0.5 mM) of enalapril and enalaprilat for 24 h. The activity of prolidase was determined by colorimetic assay. Collagen biosynthesis was evaluated by radiometric assay. Expression of signaling proteins was evaluated using Western blot. It was found that enalapril- and enalaprilat-dependent increase in prolidase activity and expression was accompanied by parallel increase in collagen biosynthesis. The exposure of the cells to 0.5 mM enalapril and enalaprilat contributed to increase in IGF-IR and α₂β₁ integrin receptor as well as TGF-β1 and NF-κB p65 expressions. Enalapril- and enalaprilat-dependent increase of collagen biosynthesis in fibroblasts results from increase of prolidase activity and expression, which may undergo through activation of α₂β₁ integrin and IGF-IR signaling as well as upregulation of TGF-β1 and NF-κB p65, the inhibitor of collagen gene expression.

Extracellular matrix and HIF-1 signaling: the role of prolidase

Hypoxia-inducible factor-1 (HIF-1) plays an important role in stress-responsive gene expression. Although primarily sensitive to hypoxia, HIF-1 signaling can be regulated by a number of stress factors including metabolic stress, growth factors and molecules present in the extracellular matrix (ECM). Degradation of ECM by metalloproteinases (MMP) is important for tumor progression, invasion and metastasis. ECM is predominantly collagen, and the imino acids (Pro and HyPro) comprise 25% of collagen residues. The final step in collagen degradation is catalyzed by prolidase, the obligate peptidase for imidodipeptides with Pro and HyPro in the carboxyl terminus. Defective wound healing in patients with inherited prolidase deficiency is associated with histologic features of angiopathy suggesting that prolidase may play a role in angiogenesis. Because HIF-1 alpha is central to angiogenesis, we considered that prolidase may modulate this pathway. To test this hypothesis, we made expression constructs of human prolidase and obtained stable transfectants in colorectal cancer cells (RKO). Overexpression of prolidase resulted in increased nuclear hypoxia inducible factor (HIF-1 alpha) levels and elevated expression of HIF-1-dependent gene products, vascular endothelial growth factor (VEGF) and glucose transporter-1 (Glut-1). The activation of HIF-1-dependent transcription was shown by prolidase-dependent activation of hypoxia response element (HRE)-luciferase expression. We used an oxygen-dependent degradation domain (ODD)-luciferase reporter construct as a surrogate for HIF-1 alpha as an in situ prolyl-hydroxylase assay. Since this reporter is degraded by VHL-dependent mechanisms, the increased levels of luciferase observed with prolidase expression reflected the decreased HIF-1 alpha prolyl hydroxylase activity. Additionally, the differential expression of prolidase in 2 breast cancer cell lines showed prolidase-dependent differences in HIF-1 alpha levels. These findings show that metabolism of imidodipeptides by prolidase plays a previously unrecognized role in angiogenic signaling.

[Effective therapy with a glycine-proline ointment in a patient with recurrent ulcers from prolidase deficiency]

INTRODUCTION

Prolidase deficiency is a rare disease. Lower leg recalcitrant ulcerations are the most characteristic symptoms.

CASE REPORT

Woman diagnosed of prolidase deficiency with leg recalcitrant and infected ulcerations. Dermatology service solicits a proline and glycline containing ointment after failing other topical treatment and a skin grafting. After initiation of treatment, ulcerations improved partially. FORMULA DESCRIPTION: According to "Real Decreto 175/2001, de 23 de febrero", Pharmacy service draws up an elaboration guide and a patient information leaflet of a proline 5%-glycine 5% water emulsive ointment.

DISCUSSION

Topical application of a glycine-proline ointment is an alternative for the treatment of recalcitrant ulcerations and it has resulted in variable response. In our patient it has been effective, with a partial improvement of leg ulcerations and a decrease in admissions due to over infection.

A nonsense mutation of PEPD in four Amish children with prolidase deficiency

Encoded by the peptidase D (PEPD) gene located at 19q12-q13.11, prolidase is a ubiquitous cytosolic enzyme that catalyzes hydrolysis of oligopeptides with a C-terminal proline or hydroxyproline. We describe here four Amish children with a severe phenotype of prolidase deficiency in the Geauga settlements of Ohio as the first report of prolidase deficiency in the Amish population as well as in the United States. The patients presented with infection, hepatosplenomegaly, or thrombocytopenia, in contrast to most cases previously reported in the literature, presenting with skin ulcers. All four patients had typical facial features, classic skin ulcers, and multisystem involvement. Recurrent infections, asthma-like chronic reactive airway disease, hyperimmunoglobulins, hepatosplenomegaly with mildly elevated aspartate transaminase (AST), anemia, and thrombocytopenia were common and massive imidodipeptiduria was universal. Prolidase activity in our patients is nearly undetectable. Direct sequencing of PCR-amplified genomic DNA for all of the exons from the four patients revealed the same homozygous single nucleotide mutation c.793 T > C in exon 11, resulting in a premature stop-codon at amino acid residue 265 (p.R265X). It is speculated that the severe phenotype in these patients might be associated with the type of the PEPD gene mutation.

A homozygous missense mutation in PEPD encoding peptidase D causes prolidase deficiency associated with hyper-IgE syndrome

BACKGROUND

Prolidase deficiency is a complex disease characterized by various skin manifestations accompanied by mental retardation, facial dysmorphism and susceptibility to pyogenic infections.

METHODS

We assessed a patient presenting a peculiar phenotype combining manifestations of prolidase deficiency with features typical of hyper-IgE syndrome. Mutation analysis was performed using direct PCR amplification and PCR restriction fragment length polymorphism analysis.

RESULTS

We identified a novel homozygous recessive mutation in the PEPD gene, which was found to segregate in the family of the patient with the disease and was not found in a panel of DNA samples representative of all major Druze families living in northern Israel.

DISCUSSION

Our results suggest that prolidase deficiency associated with hyper-IgE syndrome, a rare disorder, can be caused by mutations in PEPD.