Case series: Odontohypophosphatasia or missed diagnosis of childhood/adult-onset hypophosphatasia? – Call for a long-term follow-up of premature loss of primary teeth

AbstractIntroductionHypophosphatasia, a metabolic bone disease caused by a tissue-nonspecific alkaline phosphatase deficiency, leads to undermineralization of bone and/or teeth, impaired vitamin B6 metabolism, and a spectrum of disease presentation. At the mild end of the spectrum, it presents as pathologic fractures in later adulthood. Patients with isolated dental manifestations, typically presenting as premature loss of primary teeth, are classified as having odontohypophosphatasia (odontoHPP). A subset of patients diagnosed with odontoHPP in childhood can later develop extra-dental manifestations that constitute childhood- or adult-onset hypophosphatasia.Case reports: methods/resultsRetrospective data related to onset, detailed clinical course, and method of diagnosis were collected as part of a natural history of adult patients with hypophosphatasia.Of 9 initial patients, all had low serum alkaline phosphatase levels for their age and gender at adult presentation (Table 2). The majority (8/9) demonstrated childhood dental signs of hypophosphatasia as the initial clinical manifestation: premature loss of primary teeth (7/9), absent primary teeth (1/9), and delayed loss of primary teeth (1/9). Despite childhood dental presentation and/or other signs/symptoms, diagnosis of hypophosphatasia was delayed 20–54years (median=46) since the primary tooth problems and 8–45years (median=27) since the first fracture or onset of a major adult tooth problem.ConclusionPatients with primary tooth loss in childhood were often diagnosed with hypophosphatasia later in life. Pediatric patients classified as having odontoHPP under present practice can manifest significant disease burden later in life

Treatment of profound thrombocytopenia in a patient with Gaucher disease type 1: Is there a role for substrate reduction therapy

The availability of three enzyme replacement therapy (ERT) drugs and two substrate reduction therapy (SRT) drugs to treat Gaucher disease provides an opportunity to tailor therapies to a patient's specific clinical concerns. However, there is a gap in the literature regarding individual drug effectiveness in treating particular symptoms and the potential benefits of combination treatment. This report details treatment of a patient with Gaucher disease type 1 whose main clinical concern was profound thrombocytopenia (around 20 × 109/L, normal range: 150–450 × 109/L) with several episodes of bleeding with minimal trauma and bruises. The patient was treated with ERT at doses up to 60 units/kg weekly, with no improvement in platelet levels for 6 years. Subsequently, the patient transitioned to SRT and platelet levels increased almost two fold within the first month, and have remained stable at safe levels (30–60 × 109/L) for almost 2.5 years at the time of publication. This report demonstrates a possible therapeutic benefit of SRT in individual patients who do not meet therapeutic goals in terms of thrombocytopenia after a considerable period on first-line ERT treatment. Oral administration of SRT also improved this patient's quality of life allowing discontinuation of weekly ERT infusions, which better accommodated her demanding career and busy lifestyle

Algorithm for the early diagnosis and treatment of patients with cross reactive immunologic material-negative classic infantile pompe disease: a step towards improving the efficacy of ERT.

OBJECTIVE: Although enzyme replacement therapy (ERT) is a highly effective therapy, CRIM-negative (CN) infantile Pompe disease (IPD) patients typically mount a strong immune response which abrogates the efficacy of ERT, resulting in clinical decline and death. This study was designed to demonstrate that immune tolerance induction (ITI) prevents or diminishes the development of antibody titers, resulting in a better clinical outcome compared to CN IPD patients treated with ERT monotherapy. METHODS: We evaluated the safety, efficacy and feasibility of a clinical algorithm designed to accurately identify CN IPD patients and minimize delays between CRIM status determination and initiation of an ITI regimen (combination of rituximab, methotrexate and IVIG) concurrent with ERT. Clinical and laboratory data including measures of efficacy analysis for response to ERT were analyzed and compared to CN IPD patients treated with ERT monotherapy. RESULTS: Seven CN IPD patients were identified and started on the ITI regimen concurrent with ERT. Median time from diagnosis of CN status to commencement of ERT and ITI was 0.5 months (range: 0.1-1.6 months). At baseline, all patients had significant cardiomyopathy and all but one required respiratory support. The ITI regimen was safely tolerated in all seven cases. Four patients never seroconverted and remained antibody-free. One patient died from respiratory failure. Two patients required another course of the ITI regimen. In addition to their clinical improvement, the antibody titers observed in these patients were much lower than those seen in ERT monotherapy treated CN patients. CONCLUSIONS: The ITI regimen appears safe and efficacious and holds promise in altering the natural history of CN IPD by increasing ERT efficacy. An algorithm such as this substantiates the benefits of accelerated diagnosis and management of CN IPD patients, thus, further supporting the importance of early identification and treatment initiation with newborn screening for IPD

Algorithm for the early diagnosis and treatment of patients with cross reactive immunologic material-negative classic infantile pompe disease: a step towards improving the efficacy of ERT.

ObjectiveAlthough enzyme replacement therapy (ERT) is a highly effective therapy, CRIM-negative (CN) infantile Pompe disease (IPD) patients typically mount a strong immune response which abrogates the efficacy of ERT, resulting in clinical decline and death. This study was designed to demonstrate that immune tolerance induction (ITI) prevents or diminishes the development of antibody titers, resulting in a better clinical outcome compared to CN IPD patients treated with ERT monotherapy.MethodsWe evaluated the safety, efficacy and feasibility of a clinical algorithm designed to accurately identify CN IPD patients and minimize delays between CRIM status determination and initiation of an ITI regimen (combination of rituximab, methotrexate and IVIG) concurrent with ERT. Clinical and laboratory data including measures of efficacy analysis for response to ERT were analyzed and compared to CN IPD patients treated with ERT monotherapy.ResultsSeven CN IPD patients were identified and started on the ITI regimen concurrent with ERT. Median time from diagnosis of CN status to commencement of ERT and ITI was 0.5 months (range: 0.1-1.6 months). At baseline, all patients had significant cardiomyopathy and all but one required respiratory support. The ITI regimen was safely tolerated in all seven cases. Four patients never seroconverted and remained antibody-free. One patient died from respiratory failure. Two patients required another course of the ITI regimen. In addition to their clinical improvement, the antibody titers observed in these patients were much lower than those seen in ERT monotherapy treated CN patients.ConclusionsThe ITI regimen appears safe and efficacious and holds promise in altering the natural history of CN IPD by increasing ERT efficacy. An algorithm such as this substantiates the benefits of accelerated diagnosis and management of CN IPD patients, thus, further supporting the importance of early identification and treatment initiation with newborn screening for IPD

Representative Western gel blot showing CRIM negative status of four patients (lanes 3–6).

<p>Lane 1- protein magic marker; lane 8 -CRIM negative control cell line; lane 10 - normal human fibroblast (NHF) control; Lanes 2, 7 and 9 - left empty. 20 ug of skin fibroblast cell protein extract was loaded for each patient lane and 2.5 ug protein was loaded for NHF. Western blot was probed with anti-GAA antibody and ß-Actin was used as a protein loading control.</p

Clinical parameters.

<p>Clinical parameters.</p

Comparison of median left ventricular mass index (LVMI) values seen over time in CRIM-negative (CN) ERT monotherapy (n = 11) versus CN ERT+ITI (n = 7) treated patients.

<p>The upper limit of normal LVMI is 64 g/m² (represented by a horizontal dashed line).</p