Neuromyelitis optica-IgG in idiopathic inflammatory demyelinating disorders amongst Hong Kong Chinese

Clinical features and prognoses of acute transverse myelitis in patients with systemic lupus erythematosus

BACKGROUND/AIMS

Acute transverse myelitis (ATM) is a severe complication of systemic lupus erythematosus (SLE). This study evaluated the clinical factors related to outcome in patients with SLE-associated ATM.

METHODS

The medical records of patients diagnosed with SLE-associated ATM between January 1995 and January 2015 were reviewed. The patients were divided into two groups based on improvement of neurological deficits after treatment: favorable response group and unfavorable response group. During follow-up, the recurrence of ATM was also analyzed.

RESULTS

ATM was identified in 16 patients with SLE. All of the patients were treated with high doses of methylprednisolone (≥ 1 mg/kg daily). Although 12 patients (75%) recovered (favorable response group), four (25%) had persistent neurologic deficits (unfavorable response group) after the treatment. Compared to the favorable response group, significantly higher Systemic Lupus Erythematosus Disease Activity Index-2000, lower complement levels and initial severe neurologic deficits were found in the unfavorable response group. Among the 12 favorable response patients, five (41.7%) experienced recurrence of ATM during the followup. Patients (n = 5) who experienced relapse had a shorter duration of high-dose corticosteroid treatment (13.2 days vs. 32.9 days, p = 0.01) compared to patients who did not relapse. The mean duration of tapering-off the corticosteroid until 10 mg per day was significantly longer in non-relapse group (151.3 ± 60.8 days) than in relapse group (63.6 ± 39.4 days, p = 0.013).

CONCLUSION

Higher disease activity in SLE and initial severe neurologic deficits might be associated with the poor outcome of ATM. Corticosteroid slowly tapering-off therapy might be helpful in preventing the recurrence of ATM.

Clinical Characteristics, Treatment Outcomes and Predictive Factors in Optic Neuritis

Background:

The causes, clinical presentations and treatment outcomes of optic neuritis are distinct among different populations. Early diagnosis based on clinical presentations plays an important role in treating optic neuritis patients.

Objective:

The study aimed to determine clinical characteristics, treatment outcomes and predictive factors of treatment outcomes in optic neuritis patients with and without demyelinating disease.

Methods:

A retrospective descriptive study of optic neuritis patients carried out between January 2009 and December 2016 was done. Univariate analysis and multivariate logistic regression analysis were used to evaluate the predictive factors of treatment outcomes.

Results:

Among 150 patients with optic neuritis, 58 patients were diagnosed with Neuromyelitis Optica Spectrum Disease (NMOSD), 23 patients were diagnosed with Multiple Sclerosis (MS) and 69 patients were idiopathic. The age at presentation in the NMOSD group was significantly younger than the MS group and the idiopathic group. The female:male ratio was significantly lower in the idiopathic group than in the NMOSD group. The initial Best Corrected Visual Activity (BCVA) of 20/20-20/60 (p = 0.001) and the idiopathic group (p =0.030) was associated with good visual outcomes. Initial BCVA of < 20/200 (p = 0.009) and the NMOSD group (p < 0.001) was associated with poor visual outcomes.

Conclusion:

NMOSD is a more common cause of optic neuritis than MS in Thai population. Female patients with poor initial VA, poor response to steroids treatment, and presenting recurrent attacks are highly suspicious for NMOSD. Optic neuritis without associated demyelinating disease has a better visual outcome and lower recurrence rate.

Short myelitis lesions in aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders

IMPORTANCE

Short transverse myelitis (STM; <3 vertebral segments) is considered noncharacteristic of neuromyelitis optica (NMO) spectrum disorders (NMOSDs). Nonappreciation of the potential for STM to occur in NMOSD may lead to increased disability from delay in diagnosis and appropriate treatment.

OBJECTIVES

To determine the frequency of short lesions at the initial myelitis manifestation of NMOSD and to compare the demographic, clinical, and radiological characteristics of aquaporin-4-IgG (AQP4-IgG) seropositive and seronegative STM.

DESIGN, SETTING, AND PARTICIPANTS

We reviewed the records and images of patients at the Mayo Clinic who were identified as AQP4-IgG positive from 1996 to 2014. Inclusion criteria were first STM episode, magnetic resonance imaging performed 90 days or less from symptom onset, spinal cord T2-hyperintense lesion less than 3 vertebral segments, AQP4-IgG seropositivity, and a final diagnosis of NMO or NMOSD. Patients with an initial longitudinally extensive transverse myelitis were excluded (n = 151). Patients with STM who were seronegative for AQP4-IgG among an Olmsted County population-based cohort of inflammatory demyelinating disorders of the central nervous system were used as a control group.

MAIN OUTCOMES AND MEASURES

Delay to diagnosis in months, clinical and radiological characteristics, and disability measured by ambulatory status.

RESULTS

Twenty-five patients who were AQP4-IgG seropositive with an initial STM represented 14% of initial myelitis episodes among patients with NMOSD. The STM episode was defined as the first manifestation of NMOSD in 10 patients (40%) preceded by optic neuritis in 13 patients (52%) and preceded by a nausea and vomiting episode in 2 patients (8%). In comparison with the excluded patients with NMOSD who had an initial longitudinally extensive transverse myelitis, delay to diagnosis/treatment was greater when initial lesions were short (P = .02). In AQP4-IgG-positive STM cases, subsequent myelitis episodes were longitudinally extensive in 92%. Attributes more common in patients with AQP4-IgG-positive STM than in 27 population-based patients with AQP4-IgG-negative STM included the following: nonwhite race/ethnicity; tonic spasms; coexisting autoimmunity; magnetic resonance imaging (central cord lesions, T1 hypointensity, and a brain inconsistent with multiple sclerosis); and cerebrospinal fluid (oligoclonal bands lacking).

CONCLUSIONS AND RELEVANCE

Short transverse myelitis is not uncommon in NMOSD and, when it is present, delays diagnosis and treatment. Clinical and radiological characteristics identified in this study may help select patients with STM who are at the highest risk for an NMOSD. Short transverse myelitis does not exclude consideration of AQP4-IgG testing or NMOSD diagnosis.

Idiopathic aquaporin-4 antibody negative longitudinally extensive transverse myelitis

Background:

Longitudinally extensive transverse myelitis (LETM) is a characteristic manifestation of neuromyelitis optica (NMO). However, not all patients with LETM are positive for aquaporin-4 (AQP4) antibodies. We evaluated the characteristics of idiopathic isolated LETM negative for AQP4 antibodies.

Methods:

From the National Cancer Center registry of inflammatory diseases of the central nervous system, patients with LETM as an initial manifestation and follow-up for at least two years were enrolled. Their medical records and MRIs were reviewed retrospectively. AQP4 antibody was confirmed by three different validated methods at least three times. Cerebrospinal fluid (CSF) glial fibrillary acidic protein (GFAP) levels were measured to investigate astrocyte damage.

Results:

Among 108 patients with first-ever LETM, 55 were positive for AQP4 antibodies (P-LETM) and 53 were consistently negative. Of them, seven were later diagnosed with seronegative NMO, and four were positive for MOG antibodies. The remaining 42 patients (N-LETM) showed several features distinct from P-LETM: male predominance, older age of onset, milder clinical presentation, spinal cord confinement and absence of combined autoimmunity. CSF GFAP levels were not increased in N-LETM but were markedly elevated in P-LETM.

Conclusions:

Idiopathic isolated N-LETM is not that rare among first-ever LETM, and has many features distinct from P-LETM where astrocytic damage is evident.

Seropositive Neuromyelitis Optica imitating an Intramedullary Cervical Spinal Cord Tumor: Case Report and Brief Review of the Literature

A 44-year-old woman with progressive cervical myelopathy and central cord syndrome was noted to have an extensive cervical intramedullary contrast-enhancing lesion on magnetic resonance imaging (MRI). The lesion resembled a spinal astrocytoma or ependymoma that required surgical intervention. She was subsequently diagnosed to have neuromyelitis optica (NMO), a rare idiopathic inflammatory demyelinating disorder, when the clinical examination revealed left optic atrophy. This was confirmed by a test showing seropositivity for NMO-immunoglobulin (IgG). Disease control was achieved with corticosteroids and immunosuppressive therapy. We report a rare case of a patient with NMO who had MRI features that could have easily led to the condition being misdiagnosed as a spinal cord tumor. The importance of careful history taking, awareness of typical radiological findings and the usefulness of serum NMO-IgG as a diagnostic tool are emphasized.

Distinct serum cytokine profiles in neuromyelitis optica and multiple sclerosis

Multiple sclerosis (MS) is the most common prototypic inflammatory demyelinating disease. Neuromyelitis optica (NMO) is another inflammatory demyelinating disease of the central nervous system that exhibits clinical symptoms mainly associated with optic neuritis and myelopathy. The inflammatory reaction in MS is associated with an upregulation of a variety of T helper 1 (Th1)- or Th17-mediated cytokines. However, NMO and MS are intertwined both clinically and pathologically, which complicates their diagnosis and treatment. The aim of this study was to evaluate the differences in serum cytokine levels in patients with NMO and MS. We collected peripheral serum from patients with these central nervous system demyelinating diseases for the study. A cytometric bead array was used to assess the cytokine levels using flow cytometry. We found more inflammatory [interleukin (IL)-2 and interferon-γ) and anti-inflammatory (IL-4 and IL-10) cytokines in NMO than in MS. The differences in the optimal cutoff points of serum cytokines, including IL-2 ≥5 pg/mL, can differentiate NMO from MS. In conclusion, patients with NMO had an increased Th1-mediated inflammatory response, but similar Th17-mediated inflammation changes compared to patients with MS. Serum cytokine studies can differentiate NMO cases from MS.

Clinical features and sera anti-aquaporin 4 antibody positivity in patients with demyelinating disorders of the central nervous system from Tianjin, China

AIMS

To investigate the clinical characteristics and sera anti-aquaporin 4 (AQP4) antibody positivity in patients with inflammatory demyelinating disorders (IDDs) of the central nervous system (CNS) in Tianjin, China.

METHODS

We retrospectively evaluated 234 patients with IDDs including neuromyelitis optica (NMO), recurrent optic neuritis (rON), longitudinally extensive transverse myelitis (LETM), clinically isolated syndrome (CIS), and multiple sclerosis (MS) groups. Sera from 217 patients were determined for AQP4-Ab. The clinical characteristics and sera anti-AQP4 positivity were compared.

RESULTS

The IDDS comprised 63 MS, 51 NMO, 56 LETM, 10 rON, and 54 CIS. Compared with MS, NMO had a higher frequency of occurrence in women, intractable hiccup and nausea (IHN), medullospinal lesion, longitudinally extensive spinal cord lesions (LESCL) and bilateral ON, disease onset at a later age, and worsening residual disability. AQP4-Ab-positive rates were 84.1% and 69% in NMO and NMO spectrum disorders (NMOSD), respectively, whereas it was undetectable in all of the MS sera samples.

CONCLUSIONS

We comprehensively contrast the distinct clinical features of MS, NMO, and NMOSD in our center. A sensitive AQP4-Ab assay is necessary for the early diagnosis of NMOSD in our patients. Neither medullospinal lesion nor IHN is unique in NMO.

Central nervous system inflammatory demyelinating disorders among Hong Kong Chinese

Classical multiple sclerosis (CMS) and neuromyelitis optica spectrum disorders (NMOSD) are distinct central nervous system inflammatory demyelinating disorders (CNS IDD). Early diagnosis of CNS IDD is important as appropriate immunotherapies to optimize prognosis. We studied the diagnoses of CNS IDD among Hong Kong Chinese in a hospital-based setting. Consecutive Chinese patients who presented to our hospital with clinically isolated syndrome and subsequently diagnosed to have CNS IDD from 1980 to 2010 were reviewed. Patients with known diagnosis of CNS IDD referred for further care were excluded. Serial sera were assayed for aquaporin-4 autoantibodies (AQP4 Ab), at least 3 assays within 2-5years. A total of 210 patients diagnosed to have CNS IDD with disease duration of at least 2years were studied. Among 198 patients with serial sera available, 40 (20.2%, 20 had NMO and 20 other NMOSD) were AQP4 Ab-positive. Four patients who were AQP4 Ab-negative on the initial assay converted to AQP4 Ab-positive on repeated assays. The diagnoses of 210 patients were CMS in 88 (41.9%), NMOSD 47 (22.4%, 27 NMO, 20 other NMOSD), single attack of myelitis 23 (11.0%), single attack of optic neuritis 21 (10.0%), relapsing myelitis 10 (4.8%), acute disseminated encephalomyelitis (ADEM) 9 (4.3%), relapsing optic neuritis in 6 (2.9%), opticospinal multiple sclerosis 3 (1.4%) and single attack of brainstem encephalitis 3 (1.4%). Compared to CMS, NMOSD patients had older onset age, lower frequencies of brain MRI abnormalities and CSF OCB, higher frequency of LETM, higher CNS inflammation attack frequency in the first 2years, worse clinical outcome with higher EDSS score and mortality rate. This hospital-based study suggests that CMS (41.9%) and NMOSD (22.4%) are the most common CNS IDD among Hong Kong Chinese. NMOSD has worse clinical outcome than CMS. Detection of AQP4 Ab facilitates early diagnosis and prompts immunotherapies of NMOSD.

Aquaporin-4 autoantibodies cause asymptomatic aquaporin-4 loss and activate astrocytes in mouse

BACKGROUND

Neuromyelitis optica (NMO) is a central nervous system inflammatory demyelinating disorder. Up to 90% of patients are seropositive for aquaporin-4 autoantibodies (AQP4 Ab). The pathogenetic mechanisms underlying clinical onset and relapse of NMO are uncertain.

OBJECTIVE

Study the pathogenicity of AQP4 Ab in the absence of complement activation.

METHODS

Female C57BL/6N mice (human IgG cannot activate mouse complements) pretreated with complete Freund's adjuvant (CFA, day 0) and pertussis toxin (PTx, day 0 and day 2) were transferred with IgG isolated from serum of healthy subjects or NMO patients (AQP4 Ab-positive or negative) intraperitoneally (day 7-9). Mice were observed for signs of experimental autoimmune encephalomyelitis (EAE) by standard 6-grade EAE scores. Spinal cord was obtained at day 11 for immunohistochemistry.

RESULTS

None of the mice had clinical signs of encephalomyelitis, inflammatory cells infiltration or demyelination of spinal cord. CFA and PTx induce BBB breakdown evidenced by leakage of human IgG into cord parenchyma. Patchy areas of AQP4 loss were observed in spinal cord of mice transferred with IgG from AQP4 Ab-positive NMO patients but not in mice transferred with IgG from AQP4 Ab-negative NMO patients or healthy subjects; but there was no loss of glial fibrillary acidic protein immunoreactivity in all mice. Markedly increased proliferation of astrocytic processes suggestive of astrocytic activation was observed in mice transferred with IgG from AQP4 Ab-positive patients.

CONCLUSION

AQP4 Ab cause asymptomatic AQP4 loss and astrocytic activation but not myelitis, demyelination or astrocytic cytotoxicity in spinal cord of mouse in the absence of complement activation.

Neuromyelitis optica antibodies in patients with severe optic neuritis in China

BACKGROUND

Severe visual loss is seen in both multiple sclerosis-associated optic neuritis (ON) and neuromyelitis optica (NMO)-associated ON. NMO (aquaporin 4) antibodies have been reported to have diagnostic and prognostic value for visual and neurological outcomes of recurrent ON. We performed this study to investigate the frequency of NMO antibodies and its prognostic value for visual and neurological outcomes in Chinese patients with severe ON.

METHODS

Single-center prospective cohort study. Detection of NMO antibodies was by indirect immunofluorescence method using human aquaporin 4-transfected cells. Severe ON was defined as visual acuity of 20/200 or worse in at least 1 eye at the nadir of the patients' course. Clinical features at baseline, visual outcome, and sequential neurological events were compared between seropositive and seronegative groups.

RESULTS

NMO antibodies were detected in 11 of 34 patients (32.4%) with severe ON. Five seropositive patients with recurrent ON had significantly higher titers (range: 1:512 to 1:65,536; median: 1:512) than those of 6 seropositive patients with only 1 episode (range: 1:16 to 1:512; median: 1:32) (P=0.021). Female to male ratio (10:1) and antinuclear autoantibody positivity in seropositive patients (3 of 9, 33.3%) were statistically higher than those of the seronegative group (12:11; 0 of 19; P=0.026). The seropositive patients had significantly poorer visual outcomes than seronegative patients (P=0.025). During the averaged 32-month follow-up, 2 of 11 seropositive patients (18.2%) developed clinically incomplete transverse myelitis, while no similar symptoms were reported in the seronegative group.

CONCLUSION

NMO antibody positivity is relatively high in Chinese patients with severe ON and suggests a poorer visual outcome, probably higher risk of developing spinal cord lesions and a closer association with systemic autoimmune disorders.

Quantitative assessment of the cervical spinal cord damage in neuromyelitis optica using diffusion tensor imaging at 3 Tesla

PURPOSE

To investigate whether quantitative MRI measures of cervical spinal cord white matter (WM) using diffusion tensor imaging (DTI) in neuromyelitis optica (NMO) differed from controls and correlated with clinical disability.

MATERIALS AND METHODS

Ten referred patients and 12 healthy volunteers were imaged on a 3 Tesla scanner and patients were clinically assessed on the Expanded Disability Status Scale (EDSS). Two raters quantified DTI-derived indices from all participants, including fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity (lambda[parallel]) and perpendicular diffusivity (lambda[perpendicular]) at C1-C6 for lateral and dorsal columns. After the inter-rater reliability test, univariate correlations between DTI measures and disability were assessed using the Spearman's rho correlation coefficient. Multiple regression analysis was performed to investigate which DTI measures independently correlated with the clinical score.

RESULTS

Statistical test results indicated high reliability of all DTI measurements between two raters. NMO patients showed reduced FA, increased MD and lambda[perpendicular] compared with controls while lambda[parallel] did not show any significant difference. The former three DTI metrics also showed significant correlations with disability scores, and especially FA was found to be sensitive to mild NMO (EDSS ≤ 3)

CONCLUSION

FA is a potentially useful quantitative biomarker of otherwise normal appearing WM damage in NMO. Such damage is associated with clinical disability.

Neuromyelitis optica (NMO)--an autoimmune disease of the central nervous system (CNS)

In the past 10 years, neuromyelitis optica (NMO) has evolved from Devic's categorical clinical description into a broader disease spectrum. Serum IgG antibodies have been identified in NMO patients with the water channel aquaporin-4 (AQP4) as their main target antigen. AQP4 antibodies/NMO-IgG have been shown to be a highly specific and moderately sensitive serum biomarker for NMO. The immunopathology of NMO lesions supports that anti-AQP4 antibodies/NMO-IgG are involved in the pathogenesis of NMO. In vitro studies have demonstrated that human NMO-IgG induce necrosis and impair glutamate transport in astrocytes. Certain ethnic groups, notably of Asian and African origin, seem to be more susceptible to NMO than others. The genetic background for these putative differences is not known, a weak human leucocyte antigen association has been identified. AQP4 gene variants could represent a genetic susceptibility factor for different clinical phenotypes within the NMO spectrum. Experimental models have been described including a double-transgenic myelin-specific B- and T-cell mouse. NMO-like disease has been induced with passive transfer of human anti-AQP4 antibodies to the plasma of mice with pre-established experimental autoimmune encephalomyelitis or by intrathecal administration to naive mice. NMO may be characterized as a channelopathy of the central nervous system with autoimmune characteristics.

The prevalence of long spinal cord lesions and anti-aquaporin 4 antibodies in neuromyelitis optica patients in Taiwan

BACKGROUND AND OBJECTIVE

It was the aim of this study to determine the prevalence of anti-aquaporin 4 antibody (anti-AQP4 Ab) and long spinal cord lesions in neuromyelitis optica (NMO) and multiple sclerosis (MS) patients in Taiwan. Asia has a relatively high rate of NMO compared with MS patients. Anti-AQP4 Ab is an important marker for NMO worldwide, but serological data and clinical profiles of NMO patients in Taiwan have not been reported.

METHODS

This retrospective study compared the clinical symptoms, demographics, spinal cord lesion length and AQP4 Ab status of 34 patients with NMO with 34 patients diagnosed with conventional MS.

RESULTS

Our NMO patients were predominantly middle-aged women (median age 45 years), exhibited many relapses (1.0/year) and displayed a higher Expanded Disability Status Scale score (4.75) than conventional MS patients. NMO patients exhibited long spinal cord lesions as detected by MRI. Forty-one percent of the NMO patients had detectable anti-AQP4 Ab. The Expanded Disability Status Scale score was significantly higher in AQP4 Ab- NMO patients.

CONCLUSION

The prevalence of AQP4 Ab in a Taiwanese NMO group was 41%. Long spinal cord lesions and detection of AQP4 Ab helped to differentiate NMO patients from MS patients. Long spinal cord lesions with the anti-AQP4 Ab test may allow for an earlier diagnosis of NMO and improve therapeutic decisions.

Aquaporin-4 autoantibodies in neuromyelitis optica spectrum disorders: comparison between tissue-based and cell-based indirect immunofluorescence assays

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) are severe central nervous system inflammatory demyelinating disorders (CNS IDD) characterized by monophasic or relapsing, longitudinally extensive transverse myelitis (LETM) and/or optic neuritis (ON). A significant proportion of NMOSD patients are seropositive for aquaporin-4 (AQP4) autoantibodies. We compared the AQP4 autoantibody detection rates of tissue-based indirect immunofluorescence assay (IIFA) and cell-based IIFA.

METHODS

Serum of Chinese CNS IDD patients were assayed for AQP4 autoantibodies by tissue-based IIFA using monkey cerebellum and cell-based IIFA using transfected HEK293 cells which express human AQP4 on their cell membranes.

RESULTS

In total, 128 CNS IDD patients were studied. We found that 78% of NMO patients were seropositive for AQP4 autoantibodies by cell-based IIFA versus 61% by tissue-based IFA (p = 0.250), 75% of patients having relapsing myelitis (RM) with LETM were seropositive by cell-based IIFA versus 50% by tissue-based IIFA (p = 0.250), and 33% of relapsing ON patients were seropositive by cell-based IIFA versus 22% by tissue-based IIFA (p = 1.000); however the differences were not statistically significant. All patients seropositive by tissue-based IIFA were also seropositive for AQP4 autoantibodies by cell-based IIFA. Among 29 NMOSD patients seropositive for AQP4 autoantibodies by cell-based IIFA, 20 (69%) were seropositive by tissue-based IIFA. The 9 patients seropositive by cell-based IIFA while seronegative by tissue-based IIFA had NMO (3), RM with LETM (3), a single attack of LETM (1), relapsing ON (1) and a single ON attack (1). Among 23 NMO or RM patients seropositive for AQP4 autoantibodies by cell-based IIFA, comparison between those seropositive (n = 17) and seronegative (n = 6) by tissue-based IIFA revealed no differences in clinical and neuroradiological characteristics between the two groups.

CONCLUSION

Cell-based IIFA is slightly more sensitive than tissue-based IIFA in detection of AQP4 autoantibodies, which are highly specific for NMOSD.

Aquaporin-4 water channel expression by thymoma of patients with and without myasthenia gravis

BACKGROUND

Neuromyelitis optica (NMO) is a serious idiopathic inflammatory demyelinating disorder characterized by acute transverse myelitis and optic neuritis. A significant proportion of NMO patients are seropositive for NMO-IgG, an autoantibody targeting aquaporin-4 (AQP4) water channel. Paraneoplastic NMO associated various tumors were recently reported.

AIM

We studied the expression of AQP4 by thymoma from patients with and without myasthenia gravis (MG).

METHODS

Thymoma obtained from thymomectomy in patients with and without MG were studied by immunohistochemistry and western blot.

RESULTS

Ten thymoma patients (9 with MG) and two control patients without thymoma or MG were studied. Immunohistochemistry revealed AQP4 immunoreactivity in cell membrane of thymoma cells from all ten thymoma specimens whereas thymic tissues from patients without thymoma or MG were negative for AQP4 immunoreactivity. Western blot revealed that lysates of nine of the ten thymoma specimens reacted with anti-human AQP4 antibody with a band of ~30 kDa compatible with the molecular weight of AQP4. Interestingly, immunofluorescence revealed that IgG isolated from 2 NMO patients seropositive for NMO-IgG bound to cell membrane of thymoma cells from all ten thymoma specimens while IgG from healthy control subject did not.

CONCLUSION

Thymoma cells of patients with and without MG express AQP4. AQP4 autoantibodies from serum of NMO patients bound to AQP4 expressed on thymoma cell membrane.

Long-term outcome after total parathyroidectomy for the management of secondary hyperparathyroidism

In patients with chronic renal failure, secondary hyperparathyroidism (sHPT) is a common problem requiring surgical parathyroidectomy (PTX) if medical treatment with active vitamin D and calcimimetics fails. To minimize the risk for recurrence, we perform total PTX (tPTX) without autotransplantation. From October 1997 to January 2004, 46 patients (31 men and 15 women) underwent tPTX without autotransplantation (median age 51 years; range 19-80 years; median dialysis time before PTX 5 years; range 0-25 years). Indications for PTX were hyperparathyroid bone disease in 41 cases and calciphylaxis in 5 cases. Postoperatively, all patients were supplemented with vitamin D analogues, both calcitriol and cholecalciferol. Patients were followed up for 4-107 months (median 63 months). Although tPTX was intended in all cases, we saw recurrent or persistent hyperparathyroidism in 26% and supernumerary glands in 15% of cases. In 7 patients (15%), five or more glands were documented and in another four suspected confirming the clinical relevance of intraoperative parathyroid hormone (PTH) measurement. In our study, the positive predictive value of a low intraoperative PTH (<20 pg/ml) for a successful tPTX was 92%. 15 patients received a renal transplant after tPTX without autotransplantation. Here, an uncomplicated hypocalcaemia was noted in 3 patients. Last available calcium levels were between 1.72 and 2.66 mmol/l (median 2.35 mmol/l). After follow-up, active vitamin D was given in a median daily dose of 0.5 microg calcitriol (range 0-2.5 microg/day). There was no evidence of clinical bone disease and no pathological fractures after tPTX after a median observation period of 63 months. tPTX still offers the highest percentage of cure for sHPT, it is safe and postoperatively easily manageable. It allows for adequate supplementation with active vitamin D, and it is the most cost-effective procedure. It should be reconsidered an option for the treatment of sHPT.